Four years after the market launch of the W 221 model series, Mercedes-Benz is presenting the 2009 S-Class. Trailblazing innovations in the areas of comfort and drive engineering combined with state-of-the-art technology for enhanced safety consolidate the Mercedes -Benz flagship’s position as the brand’s innovation driver and underscore its pioneering role in the automotive industry as a whole. The technology highlights include the world’s first standard production hybrid drive with a lithium-ion battery in the S 400 HYBRID, which makes the top-of-the-line Mercedes-Benz model the most economical petrol-engine luxury saloon. The fuel consumption of 7.9 litres per 100 kilometres corresponds to carbon dioxide emissions of just 186 grams per kilometre.
The engine range further includes eight modern petrol and diesel engines that require up to seven per cent less fuel. With an average fuel consumption of 7.6 litres of diesel, the S 350 BlueEFFICIENCY is one of the most efficient models in the luxury segment. The S-Class’s traditionally exemplary standard of safety is further enhanced by a unique combination of innovative camera- and radar-based driver assistance systems which turn the luxury saloon into an "intelligent" partner on the road. These systems include Adaptive Highbeam Assist, Lane Keeping Assist, Speed Limit Assist and the advanced Night View Assist PLUS facility. Other innovations are the ATTENTION ASSIST drowsiness detection function and automatic crosswind stabilisation.
With 270,000 units sold since its market launch in autumn 2005, the W 221-series S-Class is the world’s most successful luxury saloon, and seamlessly continues the success story of the flagship model in the Mercedes line-up. Since 1951, when the model 220 began the lineage of the S-Class, Mercedes-Benz has delivered around 3.3 million passenger cars from this model series to customers.
S 400 HYBRID: the world’s most economical petrol-engined luxury saloon
The 2009 S-Class once again represents the cutting edge of automotive development. Mercedes-Benz’s technology leadership is demonstrated by the new S 400 HYBRID, which is the first production vehicle in the world to feature a hybrid drive with a lithium-ion battery. "The S 400 HYBRID is an important milestone on the way to emission-free mobility," notes Dr Dieter Zetsche, CEO of Daimler AG and head of Mercedes-Benz Cars. "Our first series production hybrid car exemplifies Mercedes-Benz’s long-standing development strategy geared towards sustainability, with its clearly defined aim of producing economical and environment-friendly premium cars without compromising on safety, comfort and superior performance."
The first hybrid drive in a series production car from Mercedes-Benz makes this S-Class model the most economical petrol-engined luxury saloon. The fuel consumption of 7.9 litres per 100 kilometres corresponds to carbon dioxide emissions of just 186 grams per kilometre. This is the lowest level worldwide in this vehicle segment, confirming the new S 400 HYBRID as the "CO2 champion of the luxury class".
The new S 400 HYBRID is the first car to be designed on the basis of the highly intelligent modular concept developed by Mercedes-Benz to give its customers the best hybrid solution for their requirements. The S 400 HYBRID, which assumes the role of technological trendsetter within this concept, offers all the essential features from the word go:
- a compact yet powerful electric motor
- the appurtenant power electronics
- a modern high-capacity lithium-ion storage battery.
The compact hybrid module combines the hybrid functions of an automatic start-stop system and energy recuperation. In all, this means that the S 400 HYBRID sets a new standard in its class, making it the world’s most economical luxury saloon with a petrol engine.
The excellent fuel consumption and the low CO2 emissions of the S 400 HYBRID are accompanied by truly superior performance potential: the modified 3.5 litre petrol engine generates 205 kW/279 hp, while the electric motor produces 15 kW/20 hp and starting torque of 160 Nm.
The Mercedes-Benz S 400 HYBRID is based on the S 350, and features an extensively modified drive train. This encompasses a further development of the 3.5-litre V6 petrol engine, an additional magneto-electric motor, the 7G-TRONIC seven-speed automatic transmission specially configured for the hybrid module, the necessary power and control electronics, the voltage converter and the high-voltage lithium-ion battery.
During braking the electric motor acts as a generator, and is able to recover kinetic energy by a process known as recuperation. During this process the electric motor works together sensitively with the engine brake of the internal combustion engine and the conventional wheel brakes. The recuperated energy is stored by a compact but efficient lithium-ion battery in the engine compartment, and retrieved when required. Major advantages over conventional nickel/metal hydride batteries include a higher energy density and greater electrical efficiency combined with more compact dimensions and a low battery weight. Thanks to space-saving installation in the engine compartment, the boot capacity and generous interior dimensions remain unchanged. The hybrid module also has a convenient start-stop function.
Efficient diesel and petrol engines
Apart from the trailblazing hybrid of the S 400 HYBRID, the range of engines for the 2009 S-Class comprises eight other powerful units: two diesel variants and six petrol engines with six, eight and twelve cylinders. Detailed fine-tuning of these engines has been supplemented with addition fuel economy measures as part of the BlueEFFICIENCY package. These include aerodynamic optimisation, demand-controlled fuel pumps and the fuel-efficient gearshift programme for the standard 7G-TRONIC automatic transmission. These measures have enabled Mercedes-Benz developers to reduce fuel consumption and CO2 emissions by up to seven percent compared to the preceding models. By means of additional well-aimed aerodynamic measures, the Mercedes-Benz engineers have also managed to reduce wind noise, thus further enhancing the standard of ride comfort.
With diesel fuel consumption of 7.6 litres per 100 kilometres and CO2 emissions of 199-201 grams per kilometre, the S 350 CDI BlueEFFICIENCY (173 kW/ 235 hp) likewise boasts outstanding figures for the luxury class. Mercedes-Benz achieves this exemplary efficiency with a tailor-made BlueEFFICIENCY package, which also includes closed underbody panelling and decoupling of the 7G‑TRONIC automatic transmission at standstill.
The 3.0 litre diesel engine is also used in the S 350 CDI 4MATIC. The second diesel variant is the eight-cylinder S 450 CDI(235 kW/320 hp) with a displacement of 4.0 litres. The range of petrol engines comprises the six-cylinder S 350/ S 350 4MATIC (200 kW/272 hp) with a displacement of 3.5 litres and the two eight-cylinder units in the S 450/S 450 4MATIC (250 kW/340 hp; displacement 4.7 litres) and S 500/S 500 4MATIC (285 kW/388 hp; displacement 5.5 litres). The flagship model is still the S 600 with the 380 kW/517 hp twelve-cylinder biturbo unit (displacement 5.5 litres), which accelerates the luxury saloon to 100 km/h in 4.6 seconds. The Mercedes-AMG high-performance contributions to the range are the S 63 AMG with its 386 kW/525 hp V8 engine (displacement 6.2 litres) and the S 65 AMGwith a 450 kW/612 hp twelve-cylinder engine (displacement 6.0 litres).
Unique combination of driver assistance systems
A world-first combination of state-of-the-art assistance and protection systems is available for the 2009 S-Class. Many of these systems are also available in the new E-Class, which has been on the market since the end of March. The new assistance systems turn the models of the E- and S-Class into "intelligent" partners for their drivers. The car is able to "see", "feel", to respond "instinctively" to detected dangers and to act "on its own initiative" in order to avoid accidents or to reduce the severity of accidents.
"Similarly to the established Mercedes inventions ABS, ESP®, Brake Assist and PRE-SAFE®, the new assistance systems are also geared to the realities of how accidents occur and what consequences they entail," observes Dr. Thomas Weber , member of the board of management at Daimler AG and responsible for corporate research and the development of Mercedes-Benz Cars. "The aim in developing these systems was to prevent particularly common and serious collisions. With this concept, the S-Class not only protects its own occupants but also plays a key role in enhancing safety for other motorists," Dr. Weber adds.
To this end, Mercedes-Benz also deploys cameras which scan the road far ahead of the vehicle, monitor the surrounding area and interpret typical critical situations. Such cameras are employed in the optionally available Adaptive Highbeam Assist system, for example. This system detects vehicles with their lights on which are travelling towards or ahead of the car in which the system is fitted and controls the headlamps such as to ensure the largest possible range without dazzling other drivers.
The Sindelfingen-based engineers have also enhanced Night View Assist, which is now equipped with a special pedestrian detection function: as soon as the system detects pedestrians ahead of the car, they are highlighted on the display to make them more readily noticeable.
Lane Keeping Assist is another system that "looks ahead" for even safer driving. The system’s computer is able to recognise lane markings by evaluating the contrasting images of the road surface and the markings. If the vehicle leaves the lane identified by the Assist function unintentionally, the driver is warned by short vibrations of the steering wheel. Unlike conventional systems of this kind, the Mercedes system is able to evaluate the driver’s activities as well, and can reliably ascertain whether the car is leaving its lane intentionally or not. There is therefore no warning if the driver accelerates before overtaking or joining a motorway, brakes heavily or enters a bend, for example.
The images supplied by the windscreen camera are also used by the new, optional Speed Limit Assist system, which identifies speed limit signs in passing and shows the relevant speed limit in the central display (standard for S 600).
Drowsiness detection on the basis of more than 70 parameters
With the drowsiness detection system ATTENTION ASSIST, the 2009 S-Class has a very sensitive feel for the attention level of its driver, and warns him in good time when he becomes drowsy. This innovative technology continuously monitors more than 70 different parameters. Once the high-resolution steering angle sensor recognises the steering behaviour that typically indicates the onset of drowsiness, a warning signal is sounded and "ATTENTION ASSIST. Break!" appears in the instrument cluster.
Mercedes-Benz has also improved the long and medium-range radar used by Brake Assist PLUS and DISTRONIC PLUS proximity control. Both systems assist the driver during emergency braking. If the driver is distracted and fails to recognise the immediate danger of a rear-end collision, the PRE-SAFE®Brake is able to intervene and brake the vehicle independently. The new generation of the system offers even greater safety: if the driver fails to react even after receiving a visual and acoustic warning, the PRE - SAFE ® Brake is able to activate the maximum braking pressure around 0.6 seconds before an accident which is identified by the system as being unavoidable — an emergency braking action that significantly mitigates the severity of the impact. The system therefore acts as an "electronic crumple zone", as it were.
Detailed fine-tuning has also given the 2009 S-Class better driving dynamics and agility. This is in large measure due to the new Direct-Steer system, where the ratio varies with the steering angle.
New: Active Body Control (ABC) compensates crosswinds
Mercedes-Benz developers have also added a crosswind stabilisation function (standard for S 600) to Active Body Control (ABC). For this purpose ABC uses the yaw rates and lateral acceleration sensors of the Electronic Stability Program ESP®to vary the wheel load distribution via the ABC spring struts, depending on the direction and intensity of the crosswind. This enables the effects of crosswinds to be compensated, or reduced to a minimum in the case of strong gusts.
The Torque Vectoring Brake provides the 2009 S-Class with added safety in critical conditions and even greater agility by specifically braking the inner rear wheel in bends so as to enable precise cornering by the saloon without compromising on driving dynamics.
State-of-the-art multimedia technology
In line with its self-assured character and its claim to be a technological trendsetter, the 2009 S-Class also sets standards where onboard infotainment is concerned. As a world first, on request Mercedes-Benz will equip its flagship model with the new SPLITVIEW technology for the COMAND control and display system centrally located in the centre console. This innovative display concept allows the driver and front passenger to view different content simultaneously on one and the same screen. While the driver uses the map-based navigation system, for example, the front passenger can be watching the latest film on DVD.
Mercedes-Benz has also extended the standard control and display system COMAND with additional functions, for example an SD memory card slot. Other new features include a modified Bluetooth® interface, which provides for a wireless link between a mobile phone and the standard onboard hands-free system, and a USB interface. These enable customers to export saved data and import them into any other S-Class. It is also possible to transfer navigation data. As an optional extra Mercedes-Benz also offers a Media Interface – a universal interface in the glove compartment for mobile audio devices such as an iPod® and USB stick (standard for S 400 HYBRID and S 600).
The optionally available COMAND APS (standard for S 400 HYBRID and S 600) is additionally equipped with a Europe-wide navigation system whose data are stored on a 40 GB hard disc. This allows particularly fast route calculation. The high level of navigating convenience is also aided by the detailed three-dimensional city map mode.
Musical entertainment is provided by a radio, a CD/DVD player with MP3 function, an equalizer with speed-dependent volume control and the Music Register with a 7.2 GB hard disc which stores around 2500 digital music files in MP3, AAC or WMA format. The system recognises music files played on CD, DVD or from the Music Register using its stored Gracenote® database, and shows the title, album and performer in the colour display. The new Music Search function enables S-Class drivers and passengers to search SD memory cards, USB sticks, CDs and DVDs for specific music titles and performers. COMAND APS also includes the latest-generation LINGUATRONIC voice-operated control system, which operates the navigation, telephone and audio devices by whole-word commands. This has the advantage that the driver no longer has to spell out his commands.
Mercedes-Benz has also increased the range of rear-seat entertainment functions in the 2009 S-Class. Passengers in the rear now have a remote control unit which enables all the audio and telematics functions of COMAND to be operated, plus access to external devices via the Media Interface. Mercedes-Benz also offers a rear-seat entertainment package with two eight-inch displays on the rear surfaces of the front seat head restraints, two wireless headphones and a separate CD/DVD player with connections for external audio and video devices.
The "Logic7" surround sound system developed by Mercedes-Benz together with the audio specialists harman/kardon® delivers outstanding performance with three-dimensional sound as a natural 360-degree musical experience for all passengers.
Design: a muscular, self-assured presence
The modified design reflects the effortless superiority and power of the S-Class Saloon. It is characterised by the more pronounced arrow-shape of the radiator grille, plus a new front bumper with a discreet light-catching contour and a chrome strip below the cooling air intakes. In future the exhaust tailpipes of all S‑Class variants will be visibly integrated into the rear bumper. The headlamps have bi-xenon technology as standard.
An even more dynamic look is ensured by the LED Light package with its striking LED arrays for daytime driving lights, indicators and marker lights (standard for S 400 HYBRID and S 600). These lend an unmistakable day-and-night design to the front end. The rear end is characterised by tail lights in an innovative LED design. Here too, a total of 52 LEDs in the form of a double-C form an unmistakable light signature.
Mercedes-Benz also makes more use of light as a styling element in the interior. In future customers who specify the optional ambient lighting (standard for S 400 HYBRID and S 600) have a choice between three lighting moods: solar (amber), neutral (white) and polar (ice-blue).
The 2009 Mercedes-Benz S-Class will be in the showrooms of the premium manufacturer’s own sales outlets and authorised dealers from June 2009, and can be ordered now.
With trailblazing innovations for even more safety, comfort and functionality, the 2009 S-Class once again sets the pace and provides decisive impulses in automobile technology. The high technological level of the luxury saloon is combined with an intriguing design that exudes the serenity, self-assurance and elegance of the vehicle even at first glance.
The 2009 Mercedes-Benz S-Class provides a choice of two body variants and nine engine variants. Customers are also able to choose between rear-wheel drive and 4MATIC all-wheel drive. Engine output ranges from 170 kW/231 hp to 380 kW/517 hp. The V6 and V8 models are optionally available with a 130-millimetre longer wheelbase; the luxurious S 600 flagship model is available only with the long wheelbase.
Innovative systems in series production
A number of new or further developed high-tech systems that enhance safety and comfort are included in the standard appointments of the new S-Class. Among them are ATTENTION ASSIST, which warns the driver when it detects signs of drowsiness, Active Body Control with crosswind stabilisation for the S 450, S 500 and S 600, the Direct-Steer system, a driver kneebag and the further refined preventive occupant protection system PRE-SAFE®.
Selection of standard appointments:
- Adaptive driver and passenger airbags
- Adaptive brake lights
- AIRMATIC with Adaptive Damping System
- Anti-lock braking system (ABS)
- ATTENTION ASSIST
- 7G-TRONIC automatic transmission
- Bluetooth® interface
- ADAPTIVE BRAKE
- COMAND system with CD/DVD player , SD card slot and USB interface
- Diesel particulate filter (for all diesel variants)
- DIRECT SELECT gearshift
- Displays in the instrument cluster and for COMAND in black with LED backlighting
- ESP® with acceleration skid control (ASR)
- Headlamp assist
- Electric parking brake
- Belt tensioners on all seats
- Automatic climate control with separate settings for front footwell area
- Kneebag for driver
- Leather upholstery (S 500 and S 600)
- Light-alloy wheels: 17-inch (S 350, S 400 HYBRID and S 350 CDI BlueEFFICIENCY) and 18-inch (S 450, S 450 CDI, S 500 and S 600)
- Memory function for the seats (S 500 and S 600)
- Metallic paintwork (S 500 and S 600)
- Nappa leather multifunction steering wheel
- NECK-PRO crash-responsive head restraints
- Two-stage rain sensor
- Tyre pressure loss warning system
- Front and outer rear seatbelts with automatic comfort-fit feature
- Sidebags front and rear
- Daytime driving lights and foglamps integrated into the bumper
- Telephone keypad
- Front seats with electric fore/aft and height adjustment with lumbar support and PRE-SAFE® positioning function
- Tinted, sound-insulating, infrared-reflecting laminated glass all round
Additional standard equipment for the long-wheelbase version of the new S-Class includes:
- Leather upholstery
- Electric rear windscreen roller blind
- Tilting/sliding glass sunroof, electric, with PRE-SAFE® function
- Heated front and rear seats
- Rear seat bench with electrically adjustable outer seats and PRE-SAFE® positioning function for the seat bench and outer head restraints
Equipment packages: substantial benefits thanks to perfect combinations
No automobile in the luxury class offers such an extensive and intelligently coordinated combination of modern assistance systems and comfort-enhancing features as the S-Class. To ensure that customers derive the greatest possible benefit from these technologies, Mercedes-Benz offers specific innovations as optional packages. This ensures that the systems work together perfectly and complement each other. In addition to their major benefits, these packages also have a clear price advantage for the customer.
- In the Driving Assistance package Mercedes-Benz mainly combines systems that can actively help to prevent rear-end collisions: the radar-based proximity cruise control system DISTRONIC PLUS, Brake Assist PLUS and the automatic braking system PRE-SAFE® Brake. This equipment package also includes Lane Keeping Assist and Blind Spot Assist.
- Mercedes-Benz has put together the LED Light package for drivers who are frequently on the road at night, or who wish to give their S-Class even further visual enhancement. This not only includes the Intelligent Light System, LED daytime driving lights as well as indicators and side lights employing LED technology, but also the innovative Adaptive Highbeam Assist (standard for S 400 HYBRID and S 600).
- Mercedes-Benz offers the Navigation package for drivers who cover high mileages. This includes the multimedia system COMAND APS with 40 GB HDD navigation, 3D map display, LINGUATRONIC voice control, the MUSIC REGISTER, Music Search and Speed Limit Assist (standard for S 400 HYBRID and S 600).
- An exclusive audio experience and video entertainment for the front passenger is provided by the Front Seat Entertainment package. This includes the SPLITVIEW display, the 6-disc DVD changer and the Harman Kardon® Logic 7® surround sound system (standard for S 600).
- In the Rear Seat Entertainment package Mercedes-Benz combines a DVD player with remote control unit and two colour displays in the front head restraints with the surround-sound system.
- For comfort-oriented customers the S-Class is available with the Front Seat Comfort package, which comprises improved active multicontour seats with massage function and dynamic function with comfort head restraints featuring adjustable side bolsters and NECK-PRO technology.
- The Rear Seat Comfort package equips the S-Class with multicontour rear seats with a massage function and comfort head restraints (standard for S 600).
- The Parking package comprises PARKTRONIC including Parking Guidance and a reversing camera (standard for S 600).
- The Memory package has electrically adjustable seats with 4-way lumbar support for the driver and front passenger, including a memory function for the seats, exterior mirrors and steering column (standard for S 500 and S 600).
- The Rear Seat Memory package for the short-wheelbase S-Class includes the rear seat unit of the long-wheelbase version with electrically adjustable outer seats and a folding centre armrest with wood trim, as well as the seat memory function.
- The KEYLESS-GO package offers additional convenience with the keyless access and starting system KEYLESS-GO and automatic boot lid closing (standard for S 600).
The S 600: luxury and performance with a distinctive appearance
Mercedes-Benz stylishly underlines the exceptional status of the twelve-cylinder S 600 with numerous distinguishing features in the exterior and interior. In addition to the model-specific radiator grille with three twin louvres, these include the V12 emblem on the flanks, model-specific, five-spoke 18-inch wheels in a bi-colour look and a large range of option packages. Standard ex factory specifications include:
- LED Light package
- Navigation package
- Front Seat Comfort package:
- Rear Seat Comfort package:
- Front Seat Entertainment package
- KEYLESS-GO package
- Comfort telephony
The active multicontour front seats and multicontour rear seats are upholstered in particularly soft "Exclusive PASSION" nappa leather. In addition to the familiar transverse contouring in the S-Class, the seats also feature longitudinal piping. This pattern is repeated in the Alcantara roof lining and interior door panels. Travelling pleasure is further enhanced by comfort head restraints in the front and rear. The V12 symbol in the backrests underlines the exclusive character of this model. When entering the car, the logo also lights up in the instrument cluster. Brown poplar wood trim with a high-gloss finish and ambient lighting as standard equipment round off the matchless appearance of the Mercedes-Benz S 600. Technical highlights include the Active Body Control suspension with crosswind stabilisation.
designo and designo Selection: individual and exclusive
For further individualisation, S-Class customers are also able to choose from a restructured range of designo features. Ten different designo paint finishes can be combined with twelve designo aniline leather interiors and four natural leather interiors – with practically no limitations on personal taste. For designo wood trim, customers have a choice between natural-grain maple and natural-grain matt oak. The unique natural stone designo trim of genuine granite is available for the S-Class in two versions - Labrador Blue Pearl and black Star Galaxy. Trim in black piano lacquer and champagne white piano lacquer can also be ordered.
With designo Selection, Mercedes-Benz is for the first time offering a special, high-end package of designo features for the long-wheelbase S-Class. Customers are able to configure their car according to their personal preferences and taste from the different designo features available. The highlight is designo lettering in solid 18-carat gold on the rear air conditioning unit cover. This is exclusive to the designo Selection.
AMG Sports package: the S-Class in a muscular and dynamic outfit
The S-Class becomes even more dynamic with the AMG Sports package with AMG bodystyling and AMG light-alloy wheels. At the front the newly-designed front apron ensures a decidedly muscular appearance to make the 2009 S-Class look even more imposing. Its distinguishing feature is a tapered air intake with a wider lower edge. The side skirts continue the design of the front bumper, with striking contours that find an echo in the rear apron. The prominent rear bumper with a black insert is the perfect finishing touch.
A particularly sporty touch is also provided by the 19-inch AMG light-alloy wheels in a five-spoke design, which are painted in sterling silver. Shod with wide-base tyres in size 255/40 (front) and 275/40 (rear), they not only fill the wheel arches to perfection to give the S-Class a decidedly dynamic appearance, but also contribute to the outstanding handling characteristics. A sporty look is also ensured by the silver-painted front brake callipers with Mercedes-Benz lettering. When equipped with the AMG Sports package, the 6-cylinder models also receive the 350-millimetre (standard: 335 mm) perforated front brake discs of the 8-cylinder variants.
The interior is characterised by a wood/leather steering wheel, black ash wood trim and sports pedals of brushed stainless steel with black rubber studs. Like the striking AMG light-alloy wheels, AMG bodystyling is available for all engine variants of the Mercedes-Benz S-Class.
Design and equipment
Modern but not fashion-driven – the S-Class represents the hallmark of Mercedes design, and stands for perfection down to the last detail in this discipline too. The unmistakable visual appearance of the flagship Mercedes model communicates progressiveness, dynamism and emotional appeal, but also prestige, physical presence and high formal value retention. As part of the model facelift, Mercedes-Benz designers have added yet more edge to the appearance of the S-Class. The modified front-end design reflects the superiority and power of the luxury saloon without appearing aggressive. This effect is heightened by the more pronounced arrow-shape of the radiator grille, which has four louvres in the six and eight-cylinder models and three twin louvres in the twelve-cylinder S 600 – updated interpretations of the classic Mercedes face.
Unmistakable look: the headlamps
The headlamps likewise make their mark from afar: their external contours remain unchanged, however the internal components and their layout have changed dramatically. This is because the S-Class is now already equipped with bi-xenon headlamps as standard. While the dipped and main beam modules are on the outside, the main beam spot reflector is on the inside. However, the most striking features of the new S-Class lights are the eyecatching driving lights at the outer edge and the indicators on the lower edge of the headlamp housings. As further highlights, round twin daytime driving lights and foglamps with chrome surrounds are integrated into the front bumper. The location of the daytime driving lights at the outer edges of the bumper underlines the muscular and serene character of the S-Class.
As an alternative Mercedes-Benz offers the high-quality LED Light package for the S-Class, which literally adds sparkling highlights (standard for S 400 HYBRID and S 600). This includes the Intelligent Light System, Adaptive Highbeam Assist and two seven-section LED strips for the daytime driving lights in the right and left of the front apron, which underline the high-tech character of the saloon. These are supplemented with two additional LED strips on the undersides of the main headlamps for the indicators and driving lights. Together with the dimmed daytime driving lights, these ensure an eyecatching and unmistakable night design.
The redesigned front bumper now features a discreet light-catching contour and a continuous chrome trim strip below the cooling air intakes. Like the daytime driving lights in their outside positions, both design features lend the 2009 S‑Class a wider, more dominant appearance. At the same time the new bumper design increases the overall length of the Mercedes-Benz flagship model by 20 millimetres to 5069 and 5226 mm (long-wheelbase version).
Luxury saloon with outstanding aerodynamics
A better view to the rear is provided by the slightly larger exterior mirrors, while the integrated LED indicator repeaters have a modified design with a fine centre division. The optimised shape of the mirror housings as a result of intensive fine-tuning in the wind tunnel ensures that the side windows hardly become soiled in poor driving conditions, and that wind noise - especially from crosswinds and when overtaking trucks - is substantially eliminated. There is another benefit: although the larger mirror housings increase the width of the S‑Class by seven millimetres to 2120 millimetres, there is an overall improvement in the saloon’s aerodynamics with the . drag coefficient reduced to Cd = 0.27.
The S 350 BLUE EFFICIENCY is additionally equipped with aerodynamically advantageous, full-surface underbody panelling that further improves the drag coefficient to Cd = 0.26. This is the best figure ever achieved in the long history of the S-Class, and significantly contributes to the exemplary efficiency of the Mercedes flagship model. Other contributing factors include the new exterior mirrors, the redesigned drainage channel in the A-pillar, the joint seals between the bonnet and headlamps and the reduced height of the spoiler lip.
Tail lights: 52 LEDs for an unmistakable light signature
What strikes you first when looking at the powerfully shaped rear of the vehicle is the new tail light design. The previous horizontal stripes in the vehicle colour have each been replaced by horizontal white light strips for reversing lights and indicators. The tail light design in the form of a double-C creates an unmistakable light signature.
A total of 52 LEDs are used in the 2009 S-Class for the tail lights as well as the indicators and brake lights. They offer distinct advantages over regular bulbs: LEDs use less energy, last for the car’s lifetime and can be activated quicker. Given the immediate visibility of the brake light therefore, they also make a significant contribution to safety. By specifying such lights the Mercedes designers and engineers are emphasising that form and function are of equal importance in their eyes.
The discreetly redesigned rear bumper, with its light-catching contour blending into the vehicle flanks and visually extended by an expressive swage line running into the powerfully flared wings, likewise underlines the high design quality of the S-Class. At the same time this feature emphasises the power of the Saloon, suggesting the safety and solidity of its stance on the road. This impression is heightened even further in the twelve-cylinder S 600, which has a chrome trim strip above the exhaust tailpipes. In future the trapezoidal exhaust tailpipes themselves are visibly integrated into the rear bumper in the six and eight-cylinder models as well. For the purpose of visual differentiation, they also feature a vertical division in the S 600.
Exquisite materials for maximum wellbeing
In the interior too, Mercedes-Benz developers have perfected the S-Class with enormous attention to detail. In addition to visual and tactile enhancements, the focus here was on driver stress relief with further improved seating comfort and the latest infotainment systems – major aspects for a car that is primarily used for long-distance journeys and must offer its occupants the maximum feeling of wellbeing.
The elegant appearance of the S-Class is in large measure due to a perfectly coordinated choice of materials. The interior design specialists have used first-class materials such as aluminium, leather and wood to this end. They have used even more wood for the 2009 S-Class, replacing the polyurethane surface of the front centre console section and cupholder cover with carefully finished wood trim. All in all, depending on the model and interior appointments, there are around 20 different wood trim elements in the interior of the S-Class – most of them hand-made and individually coordinated by specialists according to colour shade and grain.
In the 2009 S-Class, five different types of wood trim provide perfectly coordinated material and colour concepts to suit individual tastes. The base-version black interior with fabric upholstery is combined with dark-brown eucalyptus wood. Optionally, light or dark burr walnut (high-gloss) or - exclusively for the S 600 - high-gloss brown poplar are available. The AMG Sports package includes black ash wood trim.
When it comes to colour-coordinating the interior, S-Class customers now have even more choice of personal surroundings. To make the decision-making process easier, Mercedes-Benz designers have developed three new interior combinations for the colour scheme: alpaca grey/basalt grey, cashmere beige/savanna beige and chestnut brown/black. Together with an all-black interior for the comfort-oriented business saloon and the well-proven combination of sahara beige/black, this produces a total of five tasteful interior design options.
The seat covers likewise meet the highest standards. In addition to high-quality fabrics there is a choice of three different leather qualities. The leather upholstery is relatively loose-fitting, which creates a ruffled effect and immediately appears soft and inviting.
First-class seating comfort
A new 12-way seat already offers the driver and front passenger outstanding comfort even in the standard version. The fore-and-aft position, backrest and cushion angle, seat height, head restraint and seat cushion depth are electrically adjustable – independently and variably, so that each occupant is able to choose the best individual seating position. Pneumatic, two-way lumbar supports are also standard equipment for the front seats. So that the optimal seating position does not have to be changed for another driver or front passenger after being found, the S 500 and S 600 are equipped with a memory function as part of the Memory package as standard. Three memory settings can be stored for both the driver and front passenger.
Climate comfort is likewise enhanced by the optionally available actively ventilated comfort seats: a total of six miniature ventilators in the seat cushion and backrest extract cool air from the floor area of the interior and distribute it evenly through a ventilation tissue beneath the seat surface. This gentle airflow prevents the occupants from getting into a sweat even when outside temperatures are very high.
Active multicontour seat: lateral support to suit the driving situation
First-class seating comfort is assured with the optional active multicontour seats (standard for S 600) available as part of the Front Seat Comfort package. Multicontour means that the occupants are able to adapt the shape of the seat to their anatomy or personal comfort preferences. In the S-Class this is made possible by a total of eleven inflatable air chambers under the upholstery. Three of these chambers, instead of two previously, provide support for the lumbar area, while as a new feature two now provide support for the shoulder area. In addition the firmness of the seat can be adjusted by varying the spring and damper characteristics of the seat cushion. The air chambers in the seat cushions can be inflated more or less fully in three stages. The firmness of the seats is programmed using the COMAND Controller and the colour display of the operating system.
In addition, high-speed piezo valves in the air chambers adjust the charging pressure and volume of the air chambers in the side bolsters of the seat backs, depending on the steering angle, lateral acceleration and vehicle speed, to provide both driver and front seat passenger with even greater support. This active function relieves pressure on the muscular system and increases the feeling of wellbeing and safety.
The pneumatics of the multicontour system work quietly, quickly and precisely thanks to high-performance piezo valves, such that the seats can be integrated into the PRE-SAFE® preventive occupant protection system: if the PRE-SAFE® system identifies a critical driving situation, it activates the air cushions of the seat backrests in a split second. They embrace the vehicle occupants and support them in such a way that in the event of an accident, the dangerous whiplash forces of the upper body can be reduced. Mercedes-Benz offers the active multicontour seats as an optional extra, and fits them as standard to the S 600.
Comfort head restraints with manually adjustable side bolsters are also included with the active multicontour seat. These also incorporate crash-responsive NECK‑PRO technology: in the event of a rear-end collision, the head restraint is immediately moved 44 millimetres forwards and 30 millimetres upwards by a pretensioned spring to give early support to the head of the seat occupant.
Finally, the S-Class represents the state of the art in terms of seating comfort with the massage pad in the backrest of the active multicontour seat. This consists of seven air chambers that are cyclically inflated and deflated, so that the seat occupant feels a pleasant rolling sensation over the entire back area. This stimulates the muscles, improves blood circulation and helps to prevent early fatigue. The massage pad operates independently of the contour and lumbar support settings. Four massage programmes are available, from "slow and gentle" to "fast and strong".
Multicontour seats with the massage function, awarded the "Healthy Back Action" seal of approval, as well as the PRE-SAFE® positioning function are also available for the rear seats of the S-Class on request. This requires the rear seat unit with electrically adjustable outer seats, which is standard equipment in models with the long wheelbase. There is a choice of two massage programmes.
New steering wheel with a sporty look
The multifunction steering wheel of the S-Class has also been carefully modified by the Mercedes-Benz designers: in future the rim and airbag module are lined with soft nappa leather as standard. Customers are also able to order a wood/leather steering wheel as an option, with a choice of four wood types. The new, flatter airbag module also lends a sporty touch to the multifunction steering wheel.
The armrests in the front doors have also been given an updated look: to heighten their perceived value even further, they now have extended chrome trim strips. Standard equipment with the model change also includes a telephone keypad under the handrest for the COMAND Controller. This also makes it possible to enter radio frequencies, personal points of interest and navigation data.
Ambient lighting heightens the sense of wellbeing
Mercedes-Benz also makes more use of light as a styling element in the 2009 S‑Class, to give its occupants an even more pleasant motoring experience. Two further colour tones have been added to the optional ambient lighting available for the interior (standard for S 400 HYBRID and S 600). In addition to the "solar" lighting mood in warm amber, customers can now use the COMAND Controller to choose between the new "neutral" in white and "polar" in ice-blue.
The ambient lighting consists of slim optical fibres concealed beneath the wood trim strips in the front and rear doors, as well as the dashboard. Their indirect light can be dimmed in five stages via the COMAND system. With ambient lighting, the pleasant feeling of spaciousness in the S-Class is also retained during journeys at night. Moreover the light keeps the driver alert and creates a relaxed mood, therefore it greatly contributes to driver-fitness safety.
Even in its basic configuration, a sophisticated lighting concept in the S-Class heightens the sense of wellbeing in the dark. In addition to the indirect lighting from the switches and controls, there are lights in the door handle recesses and footwells that create a pleasant, amber-coloured lighting effect. An LED in the housing of the rear-view mirror is directed at the centre console as another component of the interior lighting system.
The diffused light for the front of the car has five dimmer settings and can be adjusted individually using the buttons on the multifunction steering wheel and the central display in the instrument cluster. The brightness of the front and rear footwell lighting automatically dims when the doors are closed. Reading lights are provided for the rear passengers. These are equipped with xenon crown-mirrored bulbs, which produce a bright but non-dazzling light. There are a total of 45 lights in the interior of the S-Class.
New display technology with high-contrast imagery
In line with its serene character and claim to be the technical trendsetter, the onboard infotainment systems of the 2009 S-Class also set standards in the automobile industry. This already starts with the visual presentation of information: the displays in the instrument cluster and standard control and display system COMAND are like modern LCD television screens with LED backlighting. The result is brilliant colour reproduction and crystal-clear images. As another advantage, the displays can be viewed from extreme angles with no colour distortion. The displays are black when the ignition is off. In addition to the "classic" information, Mercedes-Benz developers have integrated the warning and control lamps of the new driver assistance systems and the new fuel consumption display into the instrument cluster. S-Class drivers can activate this by selecting the menu item "Trip", and ascertain the current fuel consumption and operating range.
SPLITVIEW: two programmes on a single screen
As a world first, and on request, Mercedes-Benz will equip its flagship model with the new SPLITVIEW technology (standard for S 600) for the COMAND control and display system centrally located in the centre console. This innovative display concept allows the driver and front passenger to view different content simultaneously on one and the same screen. While the driver e.g. uses the map-based navigation system, the front passenger can be watching the latest film on DVD. For this purpose the SPLITVIEW option includes a remote control unit and wireless headphones.
The generously dimensioned, 8-inch (approx. 20 cm) COMAND screen has a backlighted active matrix colour display (TFT-LCD) in combination with SPLITVIEW. This shows two different images simultaneously by placing pixels adjacent to each other. A filter masking the display divides this mixed image in such a way that depending on the seating position, only the pixels making up one or the other image can be seen. As a result, the driver and front passenger can view different programmes on the same screen at the same time.
The driver still has access to all the information from the control and display system COMAND in the display. The front passenger is able to choose his own entertainment programme with DVDs, TV channels or music videos, but is also able to operate the telephone and navigation system. As before, he can view all the information provided by the COMAND and COMAND APS system in the display.
Personal data always to hand during a journey
Mercedes-Benz has also added additional functions to the COMAND system. In future the multimedia head unit with a radio, telephone operation and a CD/DVD player also has a slot for SD memory cards. Another new feature for COMAND and the even more versatile, optional COMAND APS system is the Bluetooth® interface, which wirelessly connects the mobile phone to the standard hands-free system. The Bluetooth® interface and likewise standard USB interface also make it possible for customers to transfer their personal address book from a mobile phone or organizer to the control and display system, where it can be stored for immediate access during a journey. Stored data can also be exported and imported into any other S-Class.
Specific search for a favourite music track
The new Music Search function enables S-Class drivers and passengers to search SD memory cards, USB sticks, CDs and DVDs for specific music tracks and artists. The search can be according to various criteria, e.g. album, music category or composer. If a name needs to be entered, the software will also tolerate spelling mistakes. The driver is therefore able to devote his full attention to the road. As a further advantage, the occupants are able to search all the connected media and devices simultaneously.
The media interface in the glove compartment as an optional extra is a universal interface for connecting an iPod, USB stick or other external audio devices (standard for S 400 HYBRID and S 600). All that is required is a suitable cable from the Mercedes accessories range. The interface includes a control unit that links the external music memory to the onboard electronics and control systems. The advantage of this is that the titles of the tracks stored on the iPod can be shown on the colour display in the dashboard and in the instrument cluster, allowing them to be selected almost effortlessly using the Controller or the buttons on the multifunction steering wheel. The battery in the audio device is also charged while it is connected to the car via the media interface.
COMAND APS: HDD navigation for a swift arrival
The infotainment system COMAND APS provides S-Class customers with even more high-end electronics that contribute greatly to a safe and relaxed arrival at their destination (standard for S 400 HYBRID and S 600). This unit is equipped with a Europe-wide navigation system whose data are stored on a 40 GB hard disc, which makes for even faster route calculation compared to a DVD-based navigation system. The high level of navigating convenience is also aided by a three-dimensional map display.
With COMAND APSthe information in a personal address book can also be used for navigation purposes - a significant benefit for S-Class drivers whose professional life is often governed by the time pressure of meetings and appointments. Depending on the structure of the personal address book, the route search can be according to a telephone-number or name. As a particularly important benefit for leasing customers or business travellers using a rented S‑Class, the data can be quickly and easily exported to an SD memory card and then imported into another S-Class.
Voice-operated control: whole-word voice input for navigation, telephone and radio
Mercedes-Benz combines COMAND APSwith the voice-operated control system LINGUATRONIC and a so-called text-to-speech function as standard. This makes it possible for route-related traffic reports, SMS messages, address book entries or radio station names to be read out. The system automatically reads out traffic reports that are relevant to the current route.
Mercedes-Benz is among the inventors of modern voice control systems, and has continuously developed its LINGUATRONIC system further in recent years. The navigation system in the new S-Class can now be operated on the basis of whole-word commands, for example: the driver no longer needs to spell out countries, towns or street names, but can simply say them as a whole word. The voice control system is equally convenient when selecting radio stations or entries from the telephone directory: all the available or stored names can be called up without previously training the voice recognition system. The system also has a stored list of synonyms. For example, the driver does not necessarily have to confirm entries or commands with "Yes", but can also say "Ok", "Right", "Good" or "Correct" instead. A special filter suppresses coughing or clearing the throat, so that a voice command does not need to be repeated. LINGUATRONIC also understands variations in tone and pronunciation due to dialects.
Music Register for 2500 tracks
For musical entertainment COMAND APS includes a radio, a CD/DVD player with MP3 function, an equalizer with speed-dependent volume control and the Music Register with a 7.2 GB hard disc which stores around 2500 digital music files in the MP3, AAC or WMA format that can be loaded from PC memory cards. The system recognises music files played on CD, DVD or from the Music Register using its stored Gracenote® database, and shows the title, album and performer in the colour display.
With an improved DAB tuner (DAB = Digital Audio Broadcasting) and additional aerials (optional), the occupants of the new S-Class can also receive digital radio stations in CD quality. The system switches to analogue reception automatically when the DAB signal is too weak. In North America the S-Class is equipped with a tuner for the digital HD radio as standard.
Comfort telephony for a mobile conference room
Mercedes-Benz specialists have also added new functions to the comfort telephony option for the 2009 S-Class (standard for the S 600). The driver and passengers are now able to conduct telephone conferences and send or receive SMS messages. Whereas the basic telephony system connects the mobile phone to the control and display system via Bluetooth®, comfort telephony connects the mobile phone to the vehicle via a telephone cradle housed in the compartment beneath the centre armrest. This interface enables the phone to be connected to the vehicle aerial, and its battery is also charged during the journey.
The ultimate listening pleasure and entertainment in the rear too
A growing number of S-Class owners like to enjoy the unrivalled comfort of the Mercedes-Benz flagship model while seated on the luxurious rear seats. To meet the expectations of these customers, Mercedes-Benz has increased the range of the Rear Seat Entertainment package in the 2009 S-Class. A remote control unit is available which enables all the audio and telematic functions of COMAND and COMAND APS to be operated, plus access to external devices via the Media Interface.
In addition, the Rear Seat Entertainment package comprises two newly designed eight-inch displays on the rear surfaces of the driver and front seat passenger head restraints, two wireless headphones and a separate CD/DVD player.
The Rear Seat Entertainment package, as well as the optional Front Seat Entertainment package (standard for S 600), also include the Harman Kardon® Logic 7® surround sound system, developed by Mercedes-Benz together with the audio specialists, which delivers three-dimensional sound as a natural 360‑degree musical experience for all passengers, from both DVD and CD and regardless of whether the source was recorded in 5.1 surround or normal stereo. The audio signals are distributed via a 600-watt amplifier connected to 15 high-performance loudspeakers. For the 2009 S-Class, the sound experts at Harman Kardon® have optimised the amplifier software and equipped the mid-range speakers with Neodym magnets. A tweeter is also installed above the centre loudspeaker. The result is an even better sound experience.
In the surround-sound system for the 2009 S-Class, a 200 x 320-millimetre oval subwoofer on the parcel shelf teams up with another two 200-millimetre bass loudspeakers in the front doors, each of which is flanked by a 100-millimetre mid-range loudspeaker, to deliver high-class bass output. An additional 43-millimetre tweeter sends out the higher frequencies to the left and right in the front. In the centre of the car is a 100-millimetre diameter mid-range speaker and above it the new tweeter, while a 165-millimetre woofer/mid-range speaker and a tweeter are fitted in each of the rear doors. In addition to the powerful subwoofer, another two mid-range speakers in the parcel shelf ensure the interior of the new S-Class is flooded with sound. The amplifier supplies the eleven main channels – centre, front left/right, side left/right and rear left/right – with 40 watts of power each, the door woofers with 80 watts and the subwoofer in the parcel shelf with 160 watts.
As an optional extra, Mercedes-Benz also offers rear-seat occupants a new telephone handset with a colour display, more rapid connections and faster access to the telephone directory stored in memory. The unit is connected to COMAND and COMAND APS via the Bluetooth® interface.
S 400 HYBRID
The S 400 HYBRID is the first passenger car model with hybrid drive to be introduced by Mercedes-Benz. Its combination of a further developed V6 petrol engine and a compact hybrid module makes the S 400 HYBRID the world’s most efficient luxury saloon with a petrol engine. In the New European Driving Cycle, the combined fuel consumption is only 7.9 litres per 100 kilometres. This produces the world’s lowest CO2 emissions in this vehicle and output class - just 186 grams per kilometre.
These exemplary figures go hand in hand with outstanding performance potential: the 3.5-litre petrol engine develops 205 kW/279 hp, while the electric motor adds another 15 kW/20 hp and a starting torque of 160 Nm. The combined output is therefore 220 kW/299 hp, with a combined maximum torque of 385 newton metres. Moreover, the new S 400 HYBRID is the first series-production model to be equipped with a particularly powerful lithium-ion battery specifically designed for automotive use. This is another pioneering step by Mercedes-Benz towards the electrification of the automobile.
The Mercedes-Benz S 400 HYBRID is based on the S 350, and features an extensively modified drive train. This encompasses a further development of the 3.5-litre V6 petrol engine, an additional magneto-electric motor, the 7G-TRONIC seven-speed automatic transmission specially configured for the hybrid module, the necessary operating and control electronics, the transformer and a high-voltage lithium-ion battery.
The compact hybrid module is a disc-shaped electric motor that also acts as a starter and generator. The system offers a double benefit, as it both helps to save fuel and increases driving enjoyment. This is partly due to the booster effect of the electric motor, as it powerfully backs up the petrol engine with additional torque of up to 160 newton metres during the high-consumption acceleration phase. The driver benefits from the combined action of these two units in the form of even more impressive torque characteristics and smooth, effortlessly superior acceleration.
The hybrid module also has a convenient ECO start/stop function, which switches the engine off when the vehicle is at a standstill – for example at traffic lights. When it is time to move off again, the electric motor almost imperceptibly restarts the main power unit. This makes a significant contribution to fuel economy and environmental protection: because the engine restarts first time, and practically instantly, emissions are also minimised during the starting phase.
When the vehicle is braked the electric motor acts as a generator, and is able to recover braking energy by a process of recuperation. Working in finely tuned partnership, the electric motor supplements the braking effect of the combustion engine and the wheel brakes to deliver a smoothly progressive braking action. The recuperated energy is stored in a compact yet highly efficient lithium-ion battery in the engine compartment, and made available when required. This complex system is managed by a high-performance control unit, which is likewise located in the engine compartment.
A milestone on the road to electrification
The centrepiece of the modular, very compact and highly efficient hybrid drive system is the new high-voltage lithium-ion battery, which was specially developed for automotive use and is the first such unit worldwide to be introduced in a series-production vehicle. In this way Mercedes-Benz is making a trailblazing contribution to the electrification of the car, with the S-Class once again playing the role of the technological trendsetter.
Major advantages over conventional nickel/metal hydride batteries include a higher energy density and better electrical efficiency, together with more compact dimensions and a lower weight. Thanks to space-saving installation in the engine compartment, where it replaces the conventional starter battery, the generous interior space and boot capacity remain unchanged. The lithium-ion battery not only stores energy for the electric motor and the electrical refrigerant compressor, but is also connected to the 12-Volt onboard network via the DC transformer to supply power to other standard consumers such as the headlamps and comfort features. The completely newly designed battery system consists of the cell block with its lithium-ion cells and the electronic cell monitoring system, the battery management function, the high-strength housing, the cooling gel, the cooling plate, the coolant feed and the high-voltage connection.
Optimised thermal efficiency lowers the engine’s fuel consumption
The 3.5-litre V6 petrol engine with variable valve control has been thoroughly re-engineered and improved. In the process the development engineers made use of the advantages offered by the Atkinson principle,where the expansion phase is longer than the compression phase. The intake valve is kept open slightly longer between the intake and compression phases, which improves the engine’s thermal efficiency while reducing the specific fuel consumption and untreated emissions. A new cylinder head, different pistons and a modified camshaft with different camshaft control increase the output by 5 kW/7 hp to 205 kW/279 hp – while reducing fuel consumption at the same time.
Fuel economy also on inter-urban journeys and motorways
Especially on rural journeys and on motorways, the S 400 HYBRID achieves a further efficiency improvement by moving the operating point of the petrol engine to produce a lower specific fuel consumption. The extremely high start-off torque made possible by the boost effect of the electric motor gives the driver a particularly exhilarating feeling of powerful acceleration, while fuel consumption and emissions are reduced.
The electric motor improves efficiency
The compact, disc-shaped electric motor, which is space-savingly installed between the engine and the 7G-TRONIC 7-speed automatic transmission, improves efficiency even further. This is a 3-phase AC external rotor magneto motor, which develops a peak output of 15 kW/20 hp and a starting torque of up to 160 newton metres with an operating voltage of 120 Volts. This compact motor also acts as a starter and generator, adopting the functions of both these conventional ancillary units.
Sophisticated interaction with the internal combustion engine makes numerous additional functions possible that positively influence the emissions and agility of the S 400 HYBRID in equal measure. Moreover, this disc-shaped motor effectively dampens torsional vibrations in the drive train, thereby further reducing noise and vibrations in the interior. The result is even more ride comfort for both driver and passengers.
"Boost" effect for even more driving pleasure
The overall system offers extensive benefits: firstly by helping to save fuel, and secondly by increasing driving pleasure with the help of the "boost" effect, where the electric motor gives powerful assistance to the petrol engine with its maximum torque of 160 newton metres right from the beginning of the fuel-intensive acceleration phase. This means that the hybrid drive system of the S 400 HYBRID moves off powerfully even from very low engine speeds, as the torque curve impressively confirms. The additional torque of the hybrid module also has a consistently positive effect during subsequent acceleration phases. In all driving situations, the driver therefore benefits from the interaction between the two units in the form of powerful responsiveness and muscular torque – but without an increased fuel consumption.
The S 400 HYBRID accelerates from zero to 100 km/h in 7.3 seconds, and reaches an electronically governed top speed of 250 km/h. The S 400 HYBRID betters the already very favourable NEDC fuel consumption of the conventionally powered S 350 by up to 2.2 litres per 100 kilometres. CO2 emissions are reduced by about 21 percent.
The ECO start/stop function already saves fuel when rolling to a stop
In addition the hybrid module features an extremely comfortable and efficient start/stop function, which already switches the engine off when the vehicle is rolling to a stop at less than 15 km/h, for example before stopping at traffic lights. When it’s time to move off again, the electric motor immediately and imperceptibly restarts the main engine as soon as the driver releases the brake pedal or operates the accelerator. This likewise contributes to fuel economy and environmental conservation: as the engine restarts practically instantly, emissions are also minimised during the starting phase. The vibrations and jolts that are unavoidable when starting with a conventional starter are also reduced to a minimum.
Steering and climatic comfort remain unchanged, as both the steering servo pump and the refrigerant compressor are electrically powered. Both systems therefore continue to operate even when the vehicle is at a standstill with the engine automatically switched off. Even the partial vacuum required for brake servo assistance is generated electrically. The intelligent control logic is able to detect whether the driver is executing a turning or parking manoeuvre. In this case the automatic start/stop function is temporarily deactivated, so that these manoeuvres can be carried out in comfort.
Every braking action generates electric power for the battery
When the vehicle decelerates, the electric motor acts as a generator and uses a process of recuperation to convert the kinetic energy into electrical energy. This energy is stored in the compact yet highly efficient lithium-ion battery, and made available when required.
The electric motor assists the engine braking effect of the internal combustion engine in two smooth, seamless stages: in stage one, on the overrun with no braking action, the electric motor acts as a generator and begins to recuperate energy. Stage two commences as soon as the driver lightly operates the brake pedal: the generator output is then increased proportionally, and perceived as heavier deceleration by the driver.
Only in the case of heavier deceleration and when more brake pedal pressure is applied are the wheel brakes activated in addition to recuperation. In this way more electrical energy can be generated, while saving wear and tear on the hydraulic braking system at the same time. To make the best possible use of this double benefit, Mercedes engineers also developed a new braking system with a new brake pedal module for the S 400 BlueHYBRID.
Cleverly located control electronics
Dedicated control electronics are required to operate the 3-phase AC electric motor in the 120-Volt high-voltage DC network. The current converter is accommodated in the space formerly occupied by the starter. As the control electronics heat up as a result of electric currents measuring up to 150 amps, the system is equipped with its own, additional low-temperature cooling circuit.
Mercedes-Benz engineers have accommodated the transformer in the right front wheel arch, where it facilitates the exchange of energy between the 120-Volt high-voltage network and the 12-Volt onboard network – and also allows the option of emergency starting with jump leads if the standard battery should lose its charge. To ensure a consistently high level of electrical efficiency, the transformer is likewise cooled by a low-temperature circuit. The 12-Volt lead/acid battery is installed in the boot, and not only supplies the standard consumers but also the monitoring system for the high-voltage components with energy. Thanks to its interaction with the lithium-ion battery, it is considerably smaller in size and lighter than usual.
Tried-and-tested automatic transmission with a new configuration
Mercedes-Benz developers also adapted the well-proven 7G-TRONIC automatic transmission to suit the hybrid drive, with newly programmed software for the transmission management system. A newly developed auxiliary oil pump ensures reliable lubrication of the transmission even during phases when the combustion engine is switched off.
This complex system is managed by the modified high-performance engine control unit. This incorporates extensive functions, and distinguishes between operating conditions such as city traffic, rural journeys, motorway driving or slow manoeuvring.
Hybrid status shown in the instrument cluster
The driver is also able to monitor the status of the hybrid drive system visually. The instrument cluster has a separate, centrally positioned display showing the energy flow during boost and recuperation phases, as well as the battery charge status.
7-stage safety concept in addition to the Mercedes-Benz standard
As is usual at Mercedes-Benz, the development engineers gave safety aspects their very special attention. Know-how incorporated into the series-production car included long years of Daimler research experience with fuel-cell technology. The challenge lay in not only complying with all the worldwide and in-house legal crash test requirements, but also in ensuring the greatest possible safety for the electrical components. This safety system already applies in production, includes workshop personnel during servicing and maintenance, and also takes the emergency services into account when passengers need to be recovered following an accident.
Accordingly the hybrid technology of the S 400 HYBRID is equipped with an extensive 7-stage safety concept.
1. In the first stage all the wiring is colour-coded to eliminate confusion, and all components are marked with safety instructions. This makes the regular quality checks easier to carry out.
2. The second stage comprises comprehensive contact protection for the entire system by means of generous insulation and newly developed, dedicated connectors.
3. As part of the third stage, the world’s first lithium-ion battery to be used in a series-production model has been given a whole package of carefully coordinated safety measures. This innovative battery is accommodated in a high-strength steel housing, and also secured in place. Bedding the battery cells in a special gel effectively dampens any jolts and knocks. There is also a blow-off vent with a rupture disc and a separate cooling circuit. An internal electronic controller continuously monitors safety and immediately signals any malfunctions.
4. The fourth stage of the safety concept includes separation of the battery terminals, individual safety-wiring for all high-voltage components and continuous monitoring by multiple interlock switches. This means that all high-voltage components are connected by an electric loop. In the event of a malfunction the high-voltage system is automatically switched off.
5. As soon as the ignition is switched to "off" or if there is a fault, circuit breakers are activated in the fifth stage so that the high-voltage components are de-energized. The battery remains charged so that the engine can be re-started at any time.
6. During an accident, the high-voltage system is completely switched off within fractions of a second (stage six).
7. As the seventh and last stage, the system is continuously monitored for short circuits.
Thanks to its compact dimensions and modular design, the additional weight of the overall system is only 75 kilograms - including the comprehensive safety systems. The superior driving experience for which a Mercedes is known is therefore ensured by this trailblazing and very versatile technology, which can be used for practically all Mercedes-Benz model series. At 595 kilograms, payload is the same as that of the S 350.
The intelligent high-performance engine management system responds very sensitively to different driving conditions, and optimally configures the drive system for the relevant application, ensuring that both fuel consumption and emissions are kept to the lowest possible level.
- At standstill the petrol engine is usually switched off, and therefore consumes no fuel. The electric drive of the refrigerant compressor and steering servo pump allows uninterrupted operation of the air conditioning and power steering. Comfort is in no way compromised, and is at the same high level as in all S-Class models. Even the partial vacuum required for brake servo assistance is generated electrically.
- Moving off and acceleratingaway gently remains a smooth and comfortable procedure. A driver who kicks down the accelerator for a brisk start benefits from the boost function of the electric motor, which produces considerably more dynamic acceleration.
- At cruising speed, the intelligent electronic management system detects the situation, for example a stretch of relaxed driving on a motorway, and automatically moves the load point of the petrol engine over to lower specific fuel consumption, thereby helping to save fuel and reduce emissions.
- When rolling to a stopthe recuperation function is activated as soon as the drive is interrupted in any way (foot off the accelerator, engine braking). Once the vehicle speed falls below 15 km/h, the petrol engine is automatically switched off.
- If the driver brakes using the brake pedal, the electric motor initially begins to convert the vehicle’s kinetic energy into electrical energy. In this case the electric motor acts as a generator, storing the kinetic energy as electrical energy in the lithium-ion battery. This process feels like an engine braking effect to the driver. The conventional disc brakes at the wheels are not yet employed. The disc brakes are only activated if the driver requires heavier deceleration, braking the car together with the engine brake and recuperation.
- Once the driver selects "R" (reverse) in the 7G-TRONIC automatic transmission when manoeuvring,‑this automatically activates the manoeuvring mode and prevents the ECO start/stop function from switching off the engine at short, frequent intervals.
- The advantages of the hybrid drive system really come into their own in city traffic, with frequent stops at red traffic lights. Already switching off the petrol engine as the car frequently coasts to a stop significantly lowers the fuel consumption and emissions, while the long recuperation phases increase the battery charge. The electric motor ensures particularly comfortable and rapid restarting when the ECO start/stop function is active.
- On rural roadsthere are frequent changes between boost, constant speed and recuperation phases. Depending on the nature of the route, large quantities of recuperation energy are available to reduce fuel consumption and emissions. The more braking and acceleration phases there are, the better: uphill and downhill gradients, as well as winding, dynamic stretches, make for the largest savings.
- The hybrid effect is inherently less important on motorways, however thanks to specific modifications to the V6 petrol engine and the 7G-TRONIC automatic transmission, the driver is also able to achieve significant fuel savings and correspondingly lower emissions on fast road stretches like these.
The S 400 BlueHybrid is produced at the Sindelfingen plant, together with the other S-Class models. The petrol engine, 7G-TRONIC automatic transmission and electric motor are first put together to form a hybrid module, then delivered to the production line as a unit.
To test the practical suitability of the hybrid drive system with a lithium-ion battery, the specialists in Sindelfingen subjected 200 pre-series examples of the S 400 HYBRID to extended trials around the globe. In the process these test vehicles covered almost ten million kilometres in the extreme heat and cold, under full acceleration and in stop-and-go traffic, and also in typical day-to-day motoring. To sum up, the drive system of the S 400 HYBRID proved to be robust, efficient and unreservedly suitable for practical operation.
Modular technologies for the environmentally friendly future of the premium car
The new S 400 HYBRID exemplifies the strategy of Mercedes-Benz, whose declared aim is to offer the brand’s customers economical and environmentally compatible premium cars – without compromising in terms of typical brand attributes such as safety, comfort and superior driving pleasure.
The fundamental development strategy that Mercedes-Benz has defined in its "Road to the Future" is focused on the modular design principle: modular drive technologies that can be used individually or in combination depending on vehicle class, operating profile and customer requirements are a key factor in this.
Mercedes-Benz has already introduced numerous solutions to meet the requirements of tomorrow. The most recent examples are the B 170 NGT with natural gas drive, the powerful, economical and clean BlueTEC SUVs introduced in the USmarket, the BlueEFFICIENCY models in the A, B, C and E-Class and – as the latest example – the S 350 CDI BlueEFFICIENCY.
Apart from the trailblazing hybrid of the S 400 HYBRID, the range of engines for the 2009 S-Class comprises eight other units: two diesels and six petrol engines with six, eight and twelve cylinders. Their fuel consumption and CO2 emissions have been reduced by up to seven percent for the same, high output. Mercedes-Benz developers have achieved these advances with aerodynamic fine-tuning, tyres with a lower rolling resistance and a higher air pressure, and modifications to the fuel pump and 7G-TRONIC automatic transmission.
Tyres with a lower rolling resistance
The 2009 S-Class makes use of tyres for which the rolling resistance has been reduced by up to ten percent, thanks to the use of specially specified rubber blends for the tyre tread and sidewall, while retaining good handling and braking characteristics. Rolling resistance is primarily caused by deformation of the tyre on contact with the road surface, known as the working defelection. This causes the vehicle to slow down and also requires it to use more energy in order to overcome this deformation resistance. As a general rule: the greater the rolling resistance, the higher the fuel consumption. As much as 20 percent of the fuel consumption can depend on the tyres.
Lower engine speeds, demand-controlled fuel pump
In addition, the standard 7G-TRONIC transmission has a fuel economy shift program in the comfort ("C") driving mode of the V6 and all V8 petrol models. This is always active when the engine is started. Thanks to earlier upshifts, the engine operates at a lower speed and therefore consumes less fuel.
In order to ensure on-demand energy management, Mercedes-Benz uses demand-controlled fuel pumps in the petrol engines of the S-Class. In this setup, the engine control unit only calls for the maximum pump output during full-load operation. In all other driving situations, the pump adapts the delivery volume and pressure in line with the current driving situation, resulting in a fuel saving of 0.15 litres per 100 kilometres (NEDC).
An additional new development: the V6 models as well as the V8 petrol-engine versions with AIRMATIC air suspension feature an electric power steering pump. The main advantage of this system is that when driving in a straight line, only a small quantity of oil is delivered to the steering gear when needed and as a result the power steering pump requires less energy.
S 350 CDI BlueEFFICIENCY: as economical as a medium-class model
Mercedes-Benz developers have come up with a tailor-made package to realise even greater savings potential in the S 350 CDIBlueEFFICIENCY. In addition to the above measures, these include aerodynamically efficient, enclosed underbody panelling and standstill decoupling of the 7G-TRONIC automatic transmission when the car is at rest. The torque converter interrupts the power flow as soon as the car comes to a stop with the engine running. This eliminates the hydrodynamic resistance of the torque converter, the engine is subjected to less load and the fuel consumption falls. This decoupling function also reduces noise and vibrations when at rest, and improves idling smoothness even further. The slip-controlled clutch is engaged as soon as the drive releases the brake pedal.
With a combined NEDC fuel consumption of up to 7.6 litres of diesel per 100 kilometres, which corresponds to CO2 emissions of 199 - 201 grams per kilometre, the 173 kW/235 hp S 350 CDI BlueEFFICIENCY has the fuel consumption and emissions of a medium-class car. At the same time this V6 CDI engine impresses with superior output and torque figures of 173 kW/235 hp and 540 Nm at 1600 rpm. Accordingly this model accelerates to 100 km/h is 7.8 seconds, with a maximum speed of 250 km/h.
This highly efficient diesel is also available in the S 350 CDI4MATIC with permanent all-wheel drive, where it consumes 7.8–8.0 litres of fuel per 100 kilometres (NEDC), corresponding to CO2 emissions of 207 - 211 grams per kilometre.
Key technical features of the engine include an aluminium crankcase, common-rail injection and piezo-electric injectors in place of solenoid valves. Their crystalline structure changes within milliseconds when subjected to an electric voltage. As a result the needle at the tip of the injector is raised with a precision of only a few thousandths of a millimetre, producing a particularly fine injection of fuel. Up to five fuel injections with a peak pressure of up to 1600 bar are possible for each power stroke.
An electrically controlled intake port shut-off modifies the swirl characteristics of the air flowing into the cylinders, which also optimises the combustion process with the aim of reducing the fuel consumption and exhaust emissions even further. The VNT turbocharger (Variable Nozzle Turbine) with electrically adjustable turbine blades, the exhaust gas recirculation with a control valve and the intake air throttling are also regulated as the situation requires on the basis of measured data.
S 450 CDI: plenty of torque with a moderate fuel consumption
The second diesel variant for the S-Class is the eight-cylinder S 450 CDI, which has the same output (235 kW/320 hp) as in the preceding model but consumes three percent less fuel (NEDC combined) at 9.1-9.3 litres per 100 kilometres.
CO2 emissions are reduced to 240 - 245 grams per kilometre.
The S 450 CDI accelerates to 100 km/h in 6.6 seconds, and has a top speed of 250 km/h (electronically limited). The 4-valve CDI engine develops a maximum torque of 730 newton metres from 2200 rpm and has a displacement of 3996 cubic centimetres. High-pressure common-rail injection with a maximum injection pressure of 1600 bar ensures highly efficient combustion. Optimised flow characteristics for the best possible gas cycle, plus two turbochargers with variable turbine geometry, guarantee a high output and torque yield. Up to five diesel injections per injection cycle, special multi-hole nozzles, piezo-electric injectors and effective exhaust gas recirculation help to reduce emissions substantially. To minimise emissions still further, this V8 engine is equipped with a maintenance-free diesel particulate filter as standard.
S 350: performance, smoothness and economy
Compared to the preceding model, the V6 petrol engine in the 2009 S-Class consumes around one percent less fuel. The combined NEDC consumption is 10.0-10.2 litres of premium petrol per 100 kilometres, while CO2 emissions have been reduced to 234 - 237 grams per kilometre. In the S 350 4MATIC the reduction in fuel consumption is even more dramatic at four percent, to 10.2 - 10.5 litres per 100 kilometres(CO2: 240 - 245 g/km).
The six-cylinder powerplant develops 200 kW/272 hp at 6000 rpm from a displacement of 3498 cc, as well as 350 newton metres of torque which is available from as low as 2400 rpm and remains constant up to 5000 rpm. That guarantees exceptional pulling power and rapid mid-range acceleration, but also relaxed driving in high gears. The S 350 sprints from standstill to 100 km/h in 7.3 seconds, and reaches a top speed of 250 km/h.
With four-valve technology and four overhead camshafts, Mercedes engineers created major conditions for an exemplary performance curve, but this was not all. In addition they developed a system by which the interaction of the 24 valves can be controlled as required – depending on the engine load – while ensuring an extremely rapid gas cycle in the cylinders: continuously variable adjustment of all four camshafts. This means that the angles of both the intake and exhaust camshafts can be continuously varied by 40 degrees, ensuring that the valves open or close at the best possible moment in any driving situation.
Tumble flaps in the intake ducts, a two-stage intake manifold and intelligent thermal management to keep the engine oil and coolant at the best possible temperature round off this high-tech package. The cylinder head and crankcase of the V6 engine are of aluminium. A balancer shaft between the two banks of cylinders ensures exemplary smoothness. This counter-rotates with the crankshaft and at the same speed.
S 450 and S 500: eight cylinder models with effortless power delivery
In the S 450 V8 petrol model, Mercedes-Benz developers have reduced the combined NEDC fuel consumption by five percent to 10.6 - 10.9 litres per 100 kilometres. CO2 emissions have fallen to 249 - 255 grams per km.
The combined NEDC fuel consumption of the S 450 4MATIC is 11.0 - 11.1 litres per 100 kilometres (256–258 g CO2/km). This is likewise five percent less than for the preceding model.
The ultra-modern 4.7-litre eight-cylinder engine generates 250 kW/340 hp and a torque of 460 newton metres at 2700 to 5000 rpm, providing the basis for outstanding performance: the S 450 accelerates to 100 km/h in 5.9 seconds, with a top speed of 250 km/h (electronically limited).
The difference is even more pronounced for the S 500: while the rear-wheel drive variant requires six percent less fuel at 11.0 - 11.2 litres per 100 kilometres (NEDC combined), the 4MATIC models are happy with seven percent less premium petrol (11.3 - 11.4 l/100 km). CO2 emissions are correspondingly lower too (S 500: 258–262 g/km; S 500 4MATIC: 264-266 g/km).
The 5.5-litre engine develops 285 kW/388 hp, with a torque of 530 newton metres. Maximum torque is available from 2800 rpm, remaining constant over a wide engine speed range up to 4800 rpm. An ideal basis for powerful acceleration and fast mid-range sprints:
- The S 500 accelerates from zero to 100 km/h in 5.4 seconds.
- In manually selected third gear, the V8 Saloon sprints from 60 to 120 km/h in just 5.6 seconds.
The maximum speed of the S 500 is likewise an electronically limited 250 km/h.
Both V8 engines are produced together with the six-cylinder unit of the S 350 in Stuttgart Bad Cannstatt. This means that all four engines come from the same family, and share the same characteristics: lightweight alloys for the blocks and cylinder heads, four overhead camshafts, four-valve technology and variable camshaft adjustment on the intake and exhaust sides for an optimal supply of fresh mixture to the cylinders.
The "quadruple", continuously variable camshaft adjustment process is further enhanced by shifting camshafts, which are used to enable opening of the exhaust valves and, therefore further improve the engine’s gas cycle. The exhaust cams are designed so that the valves open at different times during the exhaust process. As a consequence, the pressure fluctuations inherent to a V8 engine’s exhaust train are reduced. Thanks to a more constant residual gas content, a higher knock limit and improved bottom-end and mid-range cylinder charging, the shifting camshafts increase the engine’s torque and refinement.
Moreover, the V8 engines have the same technical innovations for the demand-related control of the combustion processes with which the six-cylinder engines excel: a two-stage intake module for a controlled air intake depending on the engine load and engine speed, flow-optimised air ducting for the best possible air supply to the engine and tumble flaps at the end of each intake duct for more complete combustion. As a further feature shared with the V6 units, a characteristic map controlled thermostat ensures that the engine oil and coolant are always at the optimal temperatures.
Other characteristics of the V8 engines in the S 450 and S 500 include low-friction cylinder liners made from an aluminium/silicon alloy and the forged steel crankshaft with five bearings, whose main and connecting rod bearings are induction hardened. The connecting rods are likewise of forged steel, are are weight-optimised by precision milling.
S 600: twelve-cylinder engine with twin turbochargers
The flagship model remains the S 600 with a 380 kW/517 hp twelve-cylinder biturbo engine, which accelerates the luxury saloon from zero to 100 km/h in just 4.6 seconds. Maximum torque is 830 newton metres at 1800 rpm, which makes the 5.5-litre engine one of the world’s most powerful series-production car engines. The V12 combines its impressive performance potential with exemplary smoothness and outstanding noise comfort – the best possible preconditions for refined and highly enjoyable travel.
The crankcase of the twelve-cylinder engine is made from diecast aluminium, while diecast magnesium is used for the cylinder-head covers. Fracture-split or "cracked" conrods made from high-strength forged-steel alloy, pistons made from a high-quality aluminium alloy, hollow camshafts of induction-hardened forged steel, a weight-optimised forged-steel crankshaft and a diecast aluminium sump feature among the other lightweight components of the engine.
On both sides, the turbines of the two turbochargers are integrated into the exhaust manifolds to save space, and are therefore in the best position for high efficiency. The compressed air flows through two close-coupled water intercoolers on the cylinder head covers. Depending on the engine load the air is cooled by up to 100 degrees Celsius, achieving just the right temperature and density for the combustion process.
The Mercedes-AMGhigh-performance contributions to the range are the S 63 AMG with its 386 kW/525 hp V8 engine (displacement 6.2 litres) and the S 65 AMG with a 450 kW/612 hp twelve-cylinder engine (displacement 6 litres).
Transmission: seven ratios and three driving modes
The six and eight-cylinder engines are combined with the 7G-TRONIC seven-speed automatic transmission as standard, while Mercedes-Benz combines the V12 engine of the S 600 with a five-speed automatic transmission. The DIRECT-SELECT lever on the steering column enables the driver to select "P", "N", "R" and "D" by nudging the selector. The operating commands are transferred purely electronically, by wire.
The S/C/M/ mode selector switch on the centre console allows the driver to choose between three different modes: Sport, Comfort and Manual. As well as the transmission characteristics, these modes also allow the characteristics of the accelerator pedal and the suspension (springing and damping) settings to be varied. In Manual mode, the driver changes gear using the steering-wheel gearshift buttons.
Chassis and suspension
The 2009 S-Class not only impresses with its exemplary ride and suspension comfort, but also meets the highest expectations in terms of driving dynamics and agility. This is in large measure due to various new and improved systems such as Direct-Steer, which varies the steering ratio according to the steering angle, and the modified Active Body Control (ABC) with crosswind stabilisation for the eight and twelve-cylinder models.
The basis for the exemplary ride comfort of the Mercedes-Benz S-Class is still the well-proven combination of a four-link front suspension, multi-link independent rear suspension and AIRMATIC air suspension. The intelligent combination of all systems, their precise coordination and their reliable interaction are the reason why Mercedes-Benz holds such a leading position with its flagship model.
More cornering enjoyment and steering precision thanks to the Direct-Steer system
The new Direct-Steer system was developed from the familiar speed-dependent steering that Mercedes-Benz offers for many of its models. In this case the steering effort depends on the vehicle speed – the effort required increases with the speed. In practice this means more steering comfort during parking manoeuvres and more safety at higher speeds, for example on motorways, where a greater steering effort ensures safe straight-line stability.
The new Direct-Steer system retains these positive attributes of speed-sensitive steering and adds a variable steering ratio to them. This changes depending on the steering angle. The ratio is normal when the steering is more or less centred, which makes for good straight-line stability and therefore safety. The steering ratio changes very rapidly to become more direct as soon as the steering angle reaches five degrees, reaching its end value at a steering wheel angle of ninety degrees, where the steering feels very direct. Only relatively small movements of the wheel are then required to make course corrections. With the new Direct-Steer system, the number of turns of the steering wheel required from stop to stop is reduced by around 25 percent.
The perceived effect of Direct-Steer is however even more important than measured data. Even at inner-city speeds the driver needs to turn the wheel less frantically, with changes of direction faster and involving less effort. Winding country roads also become the natural habitat of the Mercedes-Benz luxury saloon equipped with Direct-Steer, as very small steering wheel movements are necessary to steer the car. Rapid sequences of bends can be mastered almost intuitively safely and precisely, and with enormous enjoyment. This all adds up to considerably more agile handling.
Variable steering ratio by mechanical means
Despite its remarkable effect, the key component of the Direct-Steer system is simply a steering rack. Its secret lies in the teeth cut into it. Starting from the neutral position for driving straight ahead, they are spaced increasingly further apart. The change in steering ratio is therefore produced by purely mechanical means. With this solution, Mercedes engineers have been able to dispense with the complex actuators and sensor systems used by other variable steering systems. The advantages include very low susceptibility to faults and low weight. Moreover, the system always responds predictably and in the same way, while other variable steering systems sometimes require rapid adaptation by the driver in rapidly changing situations.
Torque Vectoring Brake: ESP® helps with the steering
Extra safety at the physical limits, as well as even more agility, is provided by the Torque Vectoring Brake in the 2009 S-Class – targeted, one-sided braking intervention at the inside rear wheel when cornering. If ESP® detects a tendency to understeer, the newly developed Torque Vector ing Brake generates a defined turning or yawing moment around the vehicle’s vertical axis within fractions of a second. Thanks to the different torque distribution that results, the S-Class turns into the bend under precise control without any loss of handling dynamics. The advantage of this solution over complex mechanical components such as an active steering rear axle, additional multi-disc clutches or an active differential: the Torque Vectoring Brake can be implemented without an increase in vehicle weight and therefore no disadvantages in terms of fuel consumption. This Torque Vectoring Brake function is standard equipment in the 2009 S-Class.
The S-Class steers precisely when cornering thanks to targeted braking intervention at the inside rear wheel.
Active Body Control reduces the effect of a crosswind
Mercedes-Benz offers the Active Body Control (ABC) suspension system as an optional extra for the eight-cylinder S 450 and S 500 models with rear-wheel drive. It is standard equipment for the twelve-cylinder S 600. This system, which adapts the springs to the current driving situation within fractions of a second, has been improved even further for the 2009 S-Class by the suspension engineers with the addition of crosswind stabilisation.
The effect of crosswind is largely compensated by varying the wheel load distribution.
In strong crosswinds, and depending on the direction and intensity of the wind having an effect on the vehicle, this system varies the wheel load distribution in such a way that the effects of crosswinds are largely compensated or reduced to a minimum. For this purpose the ABC control unit uses the yaw rate, steering angle and lateral acceleration sensors of the Electronic Stability Program ESP® to vary the wheel load distribution via the ABC spring struts.
The system filters out weak crosswind signals, only coming into action when a certain threshold has been exceeded. In this case the driver is assisted by a change in the diagonal wheel load distribution, for example affecting the left front wheel and the right rear wheel. Specialists refer to this as Active Body Control crossover. The resulting steering effect is sufficient to reduce the effect of the crosswind.
Crosswind stabilisation is active at speeds above 80 km/h, when travelling straight ahead or taking gentle corners. If the driver takes purposeful and immediate corrective action himself, the function deactivates itself. Trials with test drivers, in which wind conditions akin to hurricane speed were simulated, elicited a positive response from all those involved.
Technical background to ABC: In this Mercedes-Benz active suspension system, the four spring struts are equipped with microprocessor-controlled plunger cylinders that can almost completely compensate for lifting, rolling and pitching of the body. The computer uses various acceleration sensors to obtain information on the current driving situation, and compares these data with those from the pressure sensors in the spring struts and the level sensors on the control arms. The system then computes the control signals, which the servo-hydraulic valves at the front and rear axle transform into precisely metered oil flows.
Once oil flows into the plunger cylinders, this modifies the tracing point of the steel springs integrated into the spring struts, generating the necessary force
to counteract the body movements. Thanks to a constantly available hydraulic pressure of up to 200 bar, ABC is able to stabilise the body practically instantly, within fractions of a second. Short transfer lines and a fast processor enable the latest development stage of ABC to reduce body roll by 60 percent when cornering at speed.
At speeds between 65 and 140 km/h, ABC gradually lowers the suspension level by up to 15 millimetres to reduce aerodynamic drag. If more ground clearance is required on very poor road surfaces, the S-Class driver is able to raise the suspension level by 40 millimetres at the touch of a button.
AIRMATIC air suspension with Adaptive Damping System
AIRMATIC air suspension is included as standard in the S 350, S 400 HYBRID, S 450, S 500, S 350 CDI BlueEFFICIENCY and S 450 CDI, as well as the 4MATIC variants. Mercedes-Benz combines this with the Adaptive Damping System (ADS), which continuously regulates the shock absorber characteristics and takes the road conditions, driving style and vehicle load into account. The system adapts the damping forces for each individual wheel to the current situation within just 50 milliseconds.
Pressing the "S", "C" and "M" key in the centre console enables the driver to individually adjust the vehicle level and suspension. In "Comfort" mode the body is automatically lowered by up to 20 millimetres from a speed of 120 km/h, and from 100 km/h in "Sport" mode, so as to improve handling, aerodynamics and fuel economy even further. In addition to this, the driver can change the transmission characteristics of the saloon from "comfortable" to "sporty". In "Manual" mode the 7G-TRONIC automatic transmission can be shifted manually using the keys on the steering wheel.
The "S", "C" and "M" keys are also on board if the S-Class is equipped with Active Body Control.
ADAPTIVE BRAKE: high-tech brakes for maximum safety
The Mercedes-Benz S-Class also represents the technological standard where its braking system is concerned: thanks to electronic control, the standard ADAPTIVE BRAKE allows control functions that enhance safety and comfort. These include priming of the braking system in critical situations: when the driver changes abruptly from the accelerator to the brake pedal prior to emergency braking, ADAPTIVE BRAKE increases the pressure in the brake lines to bring the brake linings close to the discs, so that they are able to enage instantly, and with full force when the brake pedal is operated. In this way the system supports the standard Brake Assist and Brake Assist PLUS.
ADAPTIVE BRAKE also has safety benefits in the wet: the system briefly applies the brakes at regular intervals to wipe the film of water from the brake discs and ensure that the brakes are able to perform at their peak. This automatic brake drying function is always activated when the windscreen wipers have been operating for a certain length of time. The finely metered brake pulses are imperceptible to the driver.
After the S-Class has been braked to a standstill, briefly pressing the brake pedal a little further is all that is required to activate the HOLD function. The car is then held by the brakes, even if the driver’s foot comes off the brake pedal. In this way ADAPTIVE BRAKE prevents the car from rolling forward inadvertently when stopped at traffic lights or stuck in stop-and-go traffic, and from rolling back when facing a slope. The HOLD function is deactivated automatically when the car moves off.
Extra-large brakes guarantee maximum deceleration
Large brake discs at the front and rear provide the technological basis for safe and reliable deceleration using ADAPTIVE BRAKE. Depending on the engine installed, the disc diameters range up to 360 mm at the front and up to 330 mm at the rear. The front brake discs are perforated for all model variants. The perforations shed moisture and dirt, which increases the brakes’ reliability and maintains their excellent deceleration values even in inclement weather conditions. A 9.5-inch tandem brake booster satisfies high standards for responsiveness and ease of use.
The S-Class also features an extremely easy-to-use electric parking brake as standard. Pressing a button on the dashboard is all that is needed to activate the brake. If the driver engages a gear and drives off, the brake is automatically released. The key components of this system are two separate servo drum brakes on the rear wheels and an electric motor with speed-reducing gear that applies the brake clips by means of cables. The electric parking brake can also be engaged if the engine is switched off.
Wide choice of wheel/tyre combinations
New light-alloy wheels ensure that the Mercedes-Benz flagship model impresses with an even more dynamic appearance. The V6 saloons are shod with 17-inch wheels in a seven-spoke design, while the V8 models have newly designed 18-inch wheels with five spokes. The twelve-cylinder S 600 is fitted with 18-inch five-spoke wheels of different widths as standard (front: 8.5-inch; rear: 9.5-inch).
The tyre pressures are monitored by the standard Electronic Stability Program ESP® or, on request, the electronic tyre pressure monitoring system. Should a puncture nonetheless occur, all S-Class models are equipped with the tyre sealing kit TIREFIT and an electric air pump. An emergency spare wheel is available as optional equipment.
Effortless progress in any weather: the S-Class with 4MATIC all-wheel drive
Mercedes-Benz offers 4MATIC all-wheel drive variants of the S 350, S 450 and S 500. The centrepiece is a centre differential with a planetary gear set. The permanent, defined torque distribution of 45:55 percent between the front and rear axles ensures reliable and highly predictable driving characteristics on all road surfaces. An integrated multi-disc clutch guarantees even more traction and optimal handling stability with the onset of slip.
Mercedes-Benz combines 4MATIC with the Electronic Stability Program ESP®
and the traction system 4ETS, which specifically brakes spinning wheels and transfers the torque to the wheels which still have good traction. The system uses sensor signals to meter the automatic braking impulses that increase traction when moving off on slippery surfaces and can improve handling in critical situations. 4ETS achieves the effect of conventional differential locks and provides more comfort than the technology used in other all-wheel drive vehicles.
Owing to its compact, lightweight, low-friction design, 4MATIC all-wheel drive has definite advantages over other systems in terms of weight, fuel consumption, comfort and passive safety. Depending on the engine variant, this all-wheel drive technology incurs an unrivalled, low weight penalty of only 66 or 70 kilograms.
Active and passive safety
Following a successful commitment to occupant protection, the future focus of the developers at Mercedes-Benz will be more and more on the prevention of traffic accidents and the mitigation of their severity. The approach of the safety specialists in Sin delfingenfollows the principle of "Real Life Safety". The majority of all the safety measures are based on findings from accident research, and are a response to what actually happens during accidents. Examples include well-proven Mercedes inventions such as ABS, ESP®, Brake Assist and PRE-SAFE®. The development aim in these cases was to prevent particularly frequent and serious accidents, or at least - if an accident does occur - to mitigate the effects.
In the 2009 S-Class, Mercedes-Benz has continued this successful strategy with a pioneering synergy of the very latest assistance systems which turn the luxury saloon into an "intelligent" partner that can "see", "feel" and act independently. In line with this concept the new Mercedes-Benz model not only protects its occupants, but can also contribute decisively to the safety of other road users.
In addition to radar sensors, Mercedes-Benz also uses cameras for the first time in the S-Class - these are able to look well ahead and monitor the car’s surroundings. The system’s processors are in turn able to interpret critical situations on the basis of this information. The new camera-based assistance systems e.g. help the driver to stay in his lane, recognise speed limit signs, control the headlamps as the situation requires and provide enhanced visibility in the dark.
The right light in any driving situation with the Intelligent Light System
The Intelligent Light System (standard for S 400 HYBRID and S 600) offers five different bi-xenon light functions, each of which is suited to typical driving or weather conditions:
- Country mode
- Motorway mode
- Enhanced foglamps
- Active light function
- Cornering light function
The light system is based on powerful bi-xenon headlamps. These are variably controllable, and are networked with other electronic control units from which the headlamps obtain information about the current driving situation and distribute their beam patterns accordingly. The familiar low-beam headlamps are replaced by the new country mode, which illuminates the road verge on the driver’s side more widely and brightly than before. In the dark, this enables the driver to appraise the situation and respond more rapidly when other road users cross the vehicle’s path.
Motorway mode is activated automatically from a speed of 90 km/h, increasing the visibility range by up to 60 percent. This lighting function is activated in two stages: the Intelligent Light System first increases the output of the bi-xenon headlamps from 35 to 38 Watts, thereby increasing the light intensity with noticeably better illumination of the carriageway and its verges.
The second stage is activated from 110 km/h, when the bi-xenon module on the driver’s side is raised slightly. The beam range in motorway mode is around 120 metres; at the centre of the cone of light the driver is able to see around 50 metres further than with the previous dipped beams.
Motorway mode increases visibility by 60 percent
With the enhanced foglamps, Mercedes-Benz improves driver orientation when visibility is poor. The new lighting function is activated at speeds below 70 km/h, as soon as the rear foglamp is switched on. The variable headlamp technology incorporated in the Intelligent Light System makes it possible to pivot the bi‑xenon headlamp on the driver’s side outwards by eight degrees, while lowering the beam of light at the same time. This adjustment illuminates the inner half of the road more brightly and reduces the degree of glare from light reflected back by the fog.
The Intelligent Light System also includes the active light and cornering light functions. These are switched on automatically: depending on the steering angle, yaw rate and vehicle speed, the active headlamps pivot sideways by up to 15 degrees in fractions of a second, thereby greatly improving road illumination. On an extended bend with a radius of 190 metres, the driver is able to see 25 metres further than with conventional low-beam headlamps thanks to this system. This function operates in both low-beam and high-beam mode.
The cornering light function improves safety at crossroads, at T-junctions and on tight bends. It is activated automatically when the driver operates the turn indicators or turns the steering wheel at a speed below 40 km/h. The foglamps then swivel to illuminate the area diagonally in front of the vehicle for a distance of around 30 metres, with an angle of coverage of 65 degrees.
Mercedes-Benz combines the Intelligent Light System and Adaptive Highbeam Assist with daytime driving lights as well as indicators and side lights employing LED technology to form the LED Light package (standard for S 400 HYBRID and S 600).
Adaptive Highbeam Assist for the best possible road illumination
As part of the LED Light package, Mercedes-Benz combines the Intelligent Light System with Adaptive Highbeam Assist (standard for S 400 HYBRID and S 600). This recognises oncoming vehicles or vehicles ahead with their lights on, and dips the headlamps. It also adjusts the beam range of the headlamps to give the driver the best possible visibility – without dazzling oncoming road users. The driver is able to see the course of the road, pedestrians and potential hazards more easily, and respond at an earlier stage.
Once the system registers oncoming vehicles or vehicles ahead with their lights on, it continuously adjusts the beam range to the distance so that the cone of light ends before it meets these vehicles. Adaptive Highbeam Assist also takes the steering angle into account, dipping the headlamps on tight bends. On clear stretches of road the system smoothly switches over to main beam. Practical trials have shown that drivers travel in greater safety in the dark with Adaptive Highbeam Assist: despite oncoming traffic, dummy pedestrians positioned at the roadside were also detected at a range of around 260 metres — about 150 metres sooner than with conventional dipped headlamps. This new Mercedes assistance system therefore more than doubles the safety margin when driving at night.
Adaptive Highbeam Assist gives the best possible visibility without dazzling other drivers.
The system also relieves driver workload: he is no longer required to operate the multifunction stalk on the steering column, and can devote more attention to the road ahead. Once activated, Adaptive Highbeam Assist always ensures the best possible headlamp beam range. Research has shown that at night, the main beams are only switched on during around eight percent of all journeys.
Data transfer every 40 milliseconds
The newly developed Mercedes technology is based on a camera located on the inside of the windscreen, which monitors the traffic situation in front of the car. Thanks to an intelligent image-processing algorithm, the camera is able to detect other vehicles and the distance to them. The range of the variable-control bi-xenon headlamps is set based on these findings and adapted continuously depending on the distance to the vehicle in front or the oncoming traffic. The system operates at lightning speed, sending new data to the headlamps every 40 milliseconds.
Adaptive Highbeam Assist is ready to respond at speeds above 55 km/h, and operates autonomously once the driver has moved the rotary light switch to the "Auto" position and selected high beam using the multifunction stalk on the steering column.
Night View Assist PLUS with new function for highlighting pedestrians on the display
The Night View Assist Plus system likewise available for the S-Class uses infrared technology to enhance the driver’s range of vision when the main beams cannot be used: two separate headlamps illuminate the road with invisible, non-dazzling infrared light. A windscreen-mounted camera designed to pick up precisely this type of light records what happens in front of the car and sends the image to a display in the instrument cluster. The clear, needle-sharp greyscale image that appears here shows the scene in front of the car, allowing the driver to see pedestrians, cyclists or obstacles on the road at an early stage.
Night View Assist Plus features special pedestrian detection.
The latest development stage of the Night View Assist features special a special pedestrian-detection function: as soon as the system detects pedestrians ahead of the car, they are highlighted on the display to make it easier for the driver to see them.
Lane Keeping Assist gives a warning if the vehicles leaves its lane unintentionally
As a further system that "looks ahead", the newly developed Lane Keeping Assist is available for the 2009 S-Class. Vehicles leaving the road unintentionally is the cause of one in six serious accidents on German roads. More than one third of all traffic fatalities are victims of such accidents.
The centrepiece of this new technology is a camera on the inside of the windscreen, which is able to recognise clear lane markings by evaluating the contrasting images of the road surface and the markings. The image processing system informs an electronic control unit, which determines the position of the vehicle and recognises when the vehicle leaves its lane to the right or left unintentionally. Unlike conventional systems of this kind, the Mercedes system is able to evaluate the driver’s activities as well, and can reliably ascertain whether the car is leaving its lane intentionally or not. There is therefore no warning if the driver e.g. accelerates before overtaking or joining a motorway, brakes heavily or enters a bend.
If the system determines that the car is leaving its lane unintentionally, it activates an electric motor, causing the steering wheel to vibrate – a discreet yet highly effective way of prompting the driver to countersteer. The timing of the warning depends on the width of the road and the type of lane markings. If the car crosses over a continuous line on the road, as opposed to a broken one, the system emits its warning earlier.
Lane Keeping Assist operates at speeds of between 60 and 250 km/h, as soon as the system has detected a lane marking. The steering wheel does not vibrate to give a warning if the driver ...
- cuts a corner intentionally
- uses the turn indicators
- moves back into the original lane after overtaking
Furthermore, Lane Keeping Assist is deactivated immediately if ABS, ESP®,Brake Assist or another safety system intervenes.
Electronic image processing system recognises speed-limit signs
Intelligent electronic image processing is also the basis for the likewise newly developed Speed Limit Assist, which is available as part of the Navigation package as an optional extra for the 2009 S-Class (standard for S 400 HYBRID and S 600). This new Mercedes assistance system reminds the driver of a speed limit it has recognised. The applicable speed limit is shown in a display in the instrument cluster, and remains visible until no speed limit applies or a different speed limit is registered – an important contribution to safety, as unsuitable speeds are the cause of the most and most serious accidents worldwide.
Traffic signs indicating the speed limit appear in the instrument cluster.
A windscreen-mounted camera monitors the area in front of the car on a permanent basis, and literally has a trained eye for road signs showing speed limits. This is because a computer scans the camera image for round surfaces only and then highlights these. As a next step, a system of algorithms filters out all objects that are round but do not resemble traffic signs. Finally, a comparison with stored patterns eliminates all but those objects which the system is programmed to detect: round traffic signs indicating the speed limit. The symbols are displayed in the instrument cluster, meaning that the driver is always aware of the current speed limit and can adjust the car’s speed accordingly.
Some of the speed-limit signs in Europe – for example those seen when entering or leaving towns – are rectangular, however. In such cases, the assistance system also scans the data stored on the navigation system’s digital map to check the plausibility of the camera image. The last speed limit detected disappears from the display in the instrument cluster as soon as the car enters a built-up area, for example.
Thanks to the huge advances made in computer-based image-processing technology, Speed Limit Assist is able to work in real time, analysing the images within a fraction of a second so as to provide the driver with the required information very rapidly. It also makes no difference whether the speed-limit sign is at the side of the road or on a gantry above the road.
ATTENTION ASSIST is able to warn the driver before potentially fatal micro-sleep occurs
The attention of Mercedes-Benz accident researchers is also directed towards the dangers of micro-sleep at the wheel. Scientific studies have concluded that around 25 percent of all serious motorway accidents are caused by drowsy drivers. Accordingly this accident cause is even more significant than drinking and driving. The ATTENTION ASSIST system installed in the 2009 S-Class as standard* is able to recognise the typical signs of drowsiness and warn the driver early on that it is time to take a break.
*Not for S 400 HYBRID
The risk of falling asleep momentarily is at its greatest on long-distance journeys in the dark or in unchanging conditions because this is when drivers are most likely to suffer a lapse in attention. The sheer monotony further heightens the risk of falling asleep at the wheel. Studies show that, after just four hours of non-stop driving, reaction times can be up to 50 percent slower. So the risk of an accident doubles during this time. And the risk increases more than eight-fold after just six hours of non-stop driving!
ATTENTION ASSIST observes the driver’s behaviour and, at the start of every trip, produces an individual driver profile that is then continuously compared with current sensor data. This permanent form of monitoring is important for detecting the floating transition from awakeness to drowsiness and for warning the driver in plenty of time. The system is active at speeds of between 80 and 180 km/h.
Steering behaviour as the key indicator of drowsiness
As well as the speed, lateral acceleration and longitudinal acceleration, the Mercedes system detects steering wheel movements, use of the turn indicators or pedals and certain control inputs, and takes into account external influences such as crosswinds or road unevenness, for example. ATTENTION ASSIST monitors more than 70 different parameters. Observation of steering behaviour has proven to be extremely meaningful, as drowsy drivers find it difficult to steer a precise course in their lane and show a characteristic steering behaviour pattern. Intensive tests carried out by Mercedes engineers, involving more than 550 drivers, show that this effect occurs at a very early stage when drowsiness kicks in – often before the dangerous situation in which the driver falls asleep momentarily (microsleep phase).The crucial element of the Mercedes system is a high-resolution sensor which enables precise monitoring of steering movements and steering speed. Based on these data, ATTENTION ASSIST calculates an individual behavioural pattern during the first few minutes of every trip. This pattern is then continuously compared with the current steering behaviour and the current driving situation, courtesy of the vehicle’s electronic control unit. This process allows the system to detect typical indicators of drowsiness and warn the driver by emitting an audible signal and flashing up an unequivocal instruction on the display in the instrument cluster: "ATTENTION ASSIST. Break!"
Blind Spot Assist: radar sensors warn against dangerous lane-changes
In addition to the latest camera and image processing technology, innovative radar technology makes a major contribution to accident prevention in the 2009 S-Class. Blind Spot Assist is a prime example: first introduced in the S-Class in 2007, this system warns the driver once is recognises that a lane-change is too dangerous. In Germany alone, more than 9500 serious accidents occur each year because drivers change lanes without taking following traffic into account, or make mistakes when returning to their lane.
The Blind Spot Assist detects the area immediately adjacent to and behind the vehicle with the aid of radars.
This Mercedes system available for the S-Class as part of the Driving Assistance package can help drivers to change lanes safely: short-range radar sensors housed on both sides of the rear bumper monitor the areas directly alongside and behind the car. This process enables them to see if there is another vehicle in the next lane – in the so-called blind spot. In such situations, the system informs the driver by illuminating a red warning symbol in the lens of the exterior mirror. If the driver fails to see this warning and indicates to change lanes, a warning signal sounds as well.
DISTRONIC PLUS: keeping a safe distance with the help of radar
DISTRONIC PLUS proximity control and Brake Assist (BAS) PLUSare two more radar-based Mercedes-Benz assistance systems available for the S-Class. An analysis by Mercedes -Benz accident researchers has shown that an average of one fifth of all rear-end collisions could be prevented with this technology in Germany alone. In a further one quarter of these cases, the systems can significantly help to mitigate the severity of the accident. Interaction between radar and brake technology has the greatest safety potential of all on motorways, where around 36 percent of all rear-end collisions could be prevented.
DISTRONIC PLUSproximity control operates at speeds of between 0 and 200 km/h: it keeps the car a set distance behind the vehicle in front, applies the brakes as required and can even bring the car to a complete halt, depending on the traffic situation. If the gap to the vehicle in front narrows too quickly, the system gives the driver an audible warning and, as soon as this first warning signal sounds, automatically calculates the brake pressure required to prevent a collision in this situation. DISTRONIC PLUS is part of the Driving Assistance package.
Brake Assist (BAS) PLUS "looks ahead"
Brake Assist (BAS) PLUS detects the distance to vehicles in front and in the event of an impending rear-end collision calculates the necessary degree of braking assistance. If the driver does then in fact apply the brakes, either because traffic is building up or he has been warned by the PRE-SAFE® Brake, in fractions of a second the new Brake Assist (BAS) PLUS builds up the brake pressure calculated for the current situation and - if necessary - increases brake pressure up to full brake application.
DISTRONIC PLUS and Brake Assist (BAS) PLUS celebrated their world premiere in the S-Class in 2005. For the 2009 S-Class, Mercedes-Benz has improved this innovative radar technology even further.
Situations potentially leading to an accident are recognised by two short-range radar sensors behind the front bumper (80-degree scanning angle), which have a range of around 30 metres, and a long-range radar sensor in the radiator grille. Mercedes-Benz has improved the performance of these sensors even further. In the 2009 S-Class, the system uses a newly developed long-range radar sensor with a range of 200 rather then the previous 150 metres.
This sensor now also allows mid-range detection, monitoring the area up to 60 metres ahead of the car with a scanning angle of 60 degrees. This new technology enables the road ahead to be monitored even more precisely, with better detection of dynamic processes such as a sudden lane-change by a vehicle ahead.
PRE-SAFE® Brake acts as an "electronic crumple zone"
If the driver is distracted, and fails to heed the immediate danger of a rear-end collision and ignores the visual and acoustic warnings, the PRE-SAFE® Brake is able to intervene and brake the vehicle autonomously.
This process has two stages:
- Around 1.6 seconds before the calculated impact point – after three audible warning signals – the system initiates partial braking autonomously and decelerates the car with around 40 percent of the maximum braking power (approx four m/s²). Designed to supplement the visual and audible warnings, autonomous partial braking gives the driver a further, perceptible signal to act. If the driver then brakes immediately, the adapted braking force is made available by the Brake Assist (BAS) PLUS. If the driver swerves, the accident can be avoided at the last moment.
- The 2009 S-Class makes use of the latest development stage of the PRE-SAFE® Brake: if the driver fails to react even after this autonomous partial braking, it is able to activate the maximum braking pressure in this second stage in around 0.6 seconds before what is now recognised as an unavoidable accident — an emergency braking action that can significantly mitigate the severity of the impact. The PRE-SAFE® Brake therefore acts as something like an "electronic crumple zone" to give the occupants even greater protection.
Die PRE - SAFE ® Brake uses the same close-range and long-range radar sensors as DISTRONIC PLUS and Brake Assist ( BAS ) PLUS . Mercedes-Benz offers all three systems in combination as part of the Driving Assistance package. In Germany around 40 percent of S-Class customers equip their car with this safety technology.
The PRE-SAFE® Brake greatly reduces the severity of accidents
Mercedes-Benz has tested the functioning and effectiveness of the PRE-SAFE® Brake in practical trials and in the driving simulator. The practical trials involved around 400 drivers in Germany and the USA, who covered a total of around one million test kilometres. Mercedes engineers also conducted a series of tests lasting several weeks and involving 70 drivers in the driving simulator at the Daimler research facility in Berlin. Each of the drivers drove for half an hour and was distracted by an accident on the other side of the road, while at the same time the traffic in front of the car braked suddenly.
The results of the test, which reflects an everyday situation on the road, highlight the safety-enhancing effect of the sophisticated assistance systems: a total of 70 percent of these test drives remained accident-free thanks to the fast reactions of the drivers and the assistance provided by Brake Assist (BAS) PLUS and the PRE-SAFE® Brake. In a third of the simulator tests, those taking part were unable to avoid a crash. In these cases, automatic braking greatly reduced the accident severity. The practical trials conducted by Mercedes engineers showed that the impact speed is reduced by an average of 16 km/h by autonomous PRE‑SAFE® braking.
The PRE-SAFE®Brake is active at speeds of between 30 and 200 km/h when moving vehicles are detected in front of the car. The system also reacts if the car approaches a stationary queue of traffic, providing the car’s speed is below 70 km/h.
Just like the airbag, seat-belt tensioner, ESP® and other trailblazing Mercedes inventions, the PRE-SAFE® Brake was developed based primarily on real accident situations. When used in combination with Brake Assist (BAS) PLUS, this technology can make a key contribution towards reducing the high number of rear-end collisions or reduce the severity of such collisions. In Germany, over 17 percent of all serious road accidents involve rear-end collisions. In the USA, one in three road accidents involving deaths or injuries are rear-end collisions.
PRE-SAFE® reduces the forces acting on occupants during accidents by up to 40 percent
The PRE-SAFE® Brake is an optional component of the preventive occupant protection system PRE-SAFE®, which is standard equipment in the Mercedes-Benz S-Class and immediately takes protective action when the system recognises the danger of an accident. This intelligent Mercedes system, which had its world premiere in the S-Class in 2002 and has been continuously improved ever since, takes its lead from Nature: just as living creatures react reflexively and seek cover when danger threatens, PRE-SAFE® activates precautionary measures for the passengers. When PRE-SAFE® e.g. detects that skidding is imminent, the driver brakes sharply or the PRE-SAFE® Brake has intervened, the system tensions the front seat belts, moves the front passenger seat into the most favourable position and automatically begins to close the side windows and sliding sunroof if appropriate. The position of the electrically adjustable, individual rear seats is also improved.
PRE - SAFE ® can also be activated if the optional Brake Assist ( BAS ) PLUShas used the radar system to predict an impending collision and a certain level of deceleration is exceeded when braking. The occupants are prepared for the potential collision by preventive tensioning of the front seat belts and repositioning of the front-passenger seat, enabling the seat belts and airbags to offer the best possible protection.
As another PRE-SAFE® measure, the optional rear multicontour seats and further developed active multicontour front seats enable the driver and front passenger to be seated even more securely, thereby limiting dangerous whiplash movements by the upper body. If the PRE-SAFE® control unit detects a critical driving situation, it instantly activates the air chambers in the seat cushions and backrests. These then envelope the seat occupants and give them support. Tests at the Mercedes-Benz Technology Center have shown that this PRE-SAFE® function and preventive belt tensioning increases the distance between the shoulder and the inner door lining by up to 40 millimetres at a lateral acceleration of 0.6 g. This enables the sidebag to fulfil its protective function even more effectively.
The aim is to prepare the occupants and the car for an imminent collision, so that the seat belts and the airbags can deploy with maximum effect in the event of an impact. What’s more, the PRE-SAFE® protective measures are reversible: if the accident is averted, the advance tensioning of the seat belts is halted automatically and the occupants are able to reset the positions of the other systems. The anticipatory occupant protection system is then ready for action again straightaway.
Early accident detection is possible because PRE-SAFE® is an intelligent synergy of active and passive safety. It is linked to Brake Assist (BAS), the Electronic Stability Program (ESP®), Brake Assist (BAS) PLUS (optional), the PRE-SAFE® Brake (optional) and the short-range sensors of the DISTRONIC PLUS (optional). The sensors of these systems detect potentially critical situations and send the relevant information to the electronic control units within a matter of milliseconds. PRE-SAFE® also uses these sensor data for anticipatory occupant protection.
In the 2009 S-Class, in combination with the improved DISTRONIC PLUS and Brake Assist (BAS) PLUS, PRE-SAFE® also uses the information provided by the short-range radar sensors in the front bumper to tension the front seat belts at the very last moment before an unavoidable collision, thus reducing the forces exerted on the driver and front passenger during the crash. This PRE-SAFE® function is literally the "last resort" in anticipatory occupant protection, since the accident occurs around 200 milliseconds later. This means that the S-Class has opened up yet another new dimension in passenger car safety.
Belt tensioning reduces the forces exerted on the occupants by up to 40 percent
Analyses performed during crash tests show just how important and effective anticipatory occupant protection can be. In the case of belt tensioning, for example, the precautionary measures mean that the driver and front passenger are held in their seats in the best possible position and so do not move forwards as much in the event of an impact, thus reducing the load exerted on the head and neck area. These tests showed that the head was subjected to around 30 per cent less stress, while the Mercedes engineers recorded a reduction of around 40 per cent in the neck area.
PARKTRONIC with Parking Guidance makes slow manoeuvring easier
A newly developed system that can help the S-Class driver to park safely works on the basis of ultrasonic technology: sideways inclined sensors on the front bumper record the length of a parking space as the car drives past it (at a speed of up to 35 km/h), and indicate on the cockpit display whether the space is large enough to park in. The space must be at least 1.3 metres longer than the car. After reverse gear has been engaged, instructions for safe parking appear on the display in the instrument cluster. Parking Guidance replaces the previous Parking Assist with radar sensors.
The well-proven Mercedes system PARKTRONIC, which indicates the distance between the S-Class and an obstacle or other vehicle by means of visual and acoustic signals when parking, is also in action to assist the driver when Parking Guidance is active. As a further parking and manoeuvring aid, Mercedes-Benz offers a reversing camera that monitors the area behind the saloon and shows it in the COMAND display on the dashboard.
Individual safety according to personal height and bodyweight
If the accident is unavoidable, a powerful restraint system goes into action to protect the occupants in a way appropriate to the need and the situation. Using various sensors, a computer evaluates not only the seriousness of the accident, but also personal data describing the front-seat passenger. If the sensor in the seat cushion has identified a small passenger, and depending on the type of accident, it initially deploys only the first airbag stage so that the air cushion is less fully inflated. If it detects a larger passenger, however, both airbag stages are deployed.
In addition, the S-Class comes with the proven automatic child seat identification feature that deactivates the front passenger seat airbag when a special Mercedes-Benz child seat with transponder has been recognized.
Eleven sensors for accident detection
The S-Class has a total of eleven installed sensors that provide immediate data on the type and seriousness of a collision:
- Frontal impact: In addition to the central sensor in the airbag control unit, the S-Class is equipped with “up-front” sensors. Because of their exposed position in the front module, they detect the strength of an impact even earlier and with even more precision, so that the time between the crash and the activation of airbags and seat-belt tensioners can be reduced even further.
- Side impact:pressure sensors relay rapid, precise information to the control unit in the event of an impact from the side in the area of the doors. These sensors react when the air between the doors’ outer skin and inner lining is compressed on impact. Additional side sensors are installed in the B-pillars of the new S-Class.
- Rear impact:The central crash sensor in the interior of the S-Class detects a rear-end collision and supplies the information needed to activate the NECK-PRO headrests. If the accident is relatively major, the pyrotechnical belt tensioners are triggered in the front and rear to fix the occupants in their seats.
- Rollover: In side rollovers, a rollover sensor integrated into the airbag control unit can activate the seat-belt tensioners and windowbags.
Nine airbags as standard
With nine airbags fitted as standard, not to mention seat-belt tensioners, belt-force limiters and NECK-PRO crash-responsive head restraints for the driver and front passenger, the 2009 S-Class offers an even more extensive package of safety equipment than its predecessor. The airbags, which deploy in a matter of milliseconds in the event of an accident, for the first time include a kneebag for the driver plus two adaptive airbags for the driver and front passenger, two sidebags in the front-seat backrests and two large windowbags which extend from the A-pillar to the C‑pillar during a side impact. Rear sidebags can be ordered as optional extras.
Seat-belt force limiters for front and rear passengers
All the passengers have three-point automatic seat belts. The driver and front passenger seats and the outer seats in the rear are also equipped with seat-belt tensioners and belt force limiters. The force limiter of the front belt straps is adaptive: after attaining a certain maximum level of force, the force limiters switch to a lower level of force – the belts are loosened so that front passengers can plunge deeper into the airbags. This reduces the loads acting on the chest area of the occupants.
The steering column serves the same purpose. During a front-end impact, it collapses telescopically by up to 80 millimetres.
Sophisticated bodyshell design for high crash-resistance
The basis for the exemplary level of occupant protection is an intelligently designed bodyshell with large deformation zones at the front and rear ends. Around one half of all the components making up the bodyshell of the S-Class are of high or ultra high-strength high-tech steel alloys, which offer the maximum strength for the minimum weight. This is a top-class figure in passenger car engineering. The bonnet, front wings, doors, boot lid and other components are of aluminium.
The front module and the frame-type integral support, to which the engine, front axle and steering are attached, connect the front side members with the second side member plane above the wheel housings. During a frontal collision, this gives rise to two important paths along which forces and loads are transmitted, which is one of the major reasons for the exemplary passenger protection of the S-Class. Similarly, the solid, multi-layer side skirts can absorb large forces and divert the impact energy past the passenger compartment.
The continuous firewall cross member distributes the impact forces over a large area, into the centre tunnel and the longitudinal members at the sides. An additional upper member increases the rigidity of the firewall and reduces the extent to which the pedals are pushed into the passenger compartment during a front impact.
Practically undeformable: the passenger compartment
The passenger cell is a structure virtually immune to deformation which keeps the passengers’ survival space intact, even at high impact speeds, regardless of whether the collision is head-on, from the rear or from the side, or whether the vehicle rolls over. The use of high-strength steel and thicker panels plays as important a role here as the installation of additional load-bearing members.
A complex and carefully designed floor structure forms the sturdy foundation for comprehensive occupant protection. Eight side member sections, four cross members and a three-part tunnel reinforcement stabilize the passenger compartment in a crash, and ensure that impact forces are distributed over a large area.
Side structure made of ultra high-strength steel
In a side impact, the main elements that come into play to stabilize the passenger compartment are the sturdy side skirts, the B-pillars, the four cross members in the floor area and a solid steel section below the dashboard. Mercedes -Benz produces the sills and B-pillars using ultra high-strength steel alloys, which are far superior to all other materials in terms of their tensile strength. Side impact protection is also provided by steel reinforcing sections with a high tensile strength in the doors.
At the rear the passenger compartment is protected by a meticulously designed deformation zone. In addition to the aluminium transverse section and the steel crash boxes of the bolted rear module, this consists of two sturdy side members and a cross member in the area of the boot floor. The suspension sub-frame of the rear axle likewise forms an energy-absorbing plane in the event of an impact. The fuel tank is located in the protected area in front of the rear axle. Even with respect to rear-end protection, this means that the S-Class meets the world’s most stringent crash test standards such as the US test according to FMVSS301 at 80 km/h.