The new R-Class, the Grand Sports Tourer from Mercedes-Benz, reaffirms the role of Mercedes-Benz as the visionary and trendsetter amongst automotive brands. The unprecedented vehicle concept takes the acknowledged strengths of established vehicle categories, such as sporty saloon, estate, MPV and SUV, and fuses them to create a new car with a character all of its own, a car that is all about the three Ds: Design, Dimensions and Dynamism. The model range in the new R-Class has two body variants: the Grand Sports Tourer with a wheelbase of 2980 millimetres was developed specifically for Europe and other markets. The longer version, predominantly aimed at the US market but which is also available for European customers, has a wheelbase of 3215 millimetres. There is a choice of three engines with six and eight cylinders, including the latest V6 diesel unit with a muscular 510 newton metres of torque and a fuel consumption of 9.3 litres per 100/km.
The concept of the Grand Sports Tourer caters to the needs of modern-minded people looking for a car that offers tremendous versatility combined with athletic performance. Quite apart from boasting ample spaciousness, exemplary standards of safety and impeccable comfort for up to six passengers, the new R-Class also enthrals with its beguiling styling, prestigious flair and, last but by no means least, its dynamism out on the road. To put it in a nutshell: the Grand Sports Tourer provides a wholly new motoring experience.
The design provides a visual expression of the poised, assured and dynamic character of the new R-Class. The front end is dominated by a striking radiator grille whose long, horizontal louvres symbolise strength and energy - attributes which characterise more than just the shape of the Grand Sports Tourer. The arching roof line provides a sweeping link between the A-pillar and D-pillar and lends the car a sleek, coupé-like silhouette.
First-class space and comfort for six passengers
Measuring 4922 or 5157 millimetres from nose to tail, the body of the new Mercedes-Benz R-Class has the dimensions of a luxury saloon but is considerably more spacious inside. This is due primarily to the sophisticated vehicle concept and a dimensional design that has been ingeniously planned right down to the finest detail. Up to six passengers can be accommodated in three seat rows in the R-Class – each of them with a window seat. Anybody settling down in one of the individual seats will soon notice another characteristic of the R-Class: space travel on wheels.
The seat spacing, an important criterion when it comes to freedom of movement and spatial comfort, amounts to 860 or 920 millimetres between the first and second rows, equivalent to the level found in luxury saloons. The kneeroom is 119 and 175 millimetres. Likewise, the figures for headroom (rear: up to 1027 millimetres) and shoulder room (front 1530 millimetres, rear up to 1514 millimetres) take the levels of space and comfort aboard the Mercedes-Benz R-Class into a new dimension.
Families who are keen on sports and recreational activities and who are looking for a versatile car that can adapt to all manner of transportation tasks quickly and easily are also catered for by the new R-Class as only Mercedes knows how. The four seats in the rear fold flat individually, allowing the load capacity to be expanded to as much as 1950 or 2385 litres (VDA measuring method). Loading and unloading is particularly straightforward, courtesy of the level load floor and the generously proportioned EASY-PACK tailgate.
Powerful petrol engines and a new V6 diesel with the latest common-rail technology
Engine outputs range from 165 kW/224 hp up to 225 kW/306 hp, clearly signalling just what the new R-Class is capable of in terms of dynamism and motoring enjoyment. The powerful V8 powerplant under the bonnet of the R 500 propels it from standstill to 100 km/h in just 6.9 or 7.0 seconds and on to a top speed of 245 km/h. Also to be found in the engine line-up is a new six-cylinder diesel power unit with third-generation common-rail, direct-injection technology, whose credentials include improved fuel consumption, even lower exhaust emissions and an audible improvement in refinement. The V6 engine places its class-beating peak torque of 510 newton metres on tap from as low down as 1600 rpm.
Powered by the new 200-kW/272-hp V6 petrol engine, the R 350 accelerates from 0-100 km/h in just 8.3 or 8.4 seconds and goes on to reach a top speed of 230 km/h.
All engine models are partnered as standard by the 7G-TRONIC seven-speed automatic transmission, which itself comes with a noteworthy new feature in the form of DIRECT SELECT. This electronic transmission control system has allowed Mercedes engineers to dispense with the conventional automatic selector lever in the centre console and to replace it instead with a lever on the steering column. Additional gearshift buttons on the steering wheel enable drivers to manually pre-select the seven forward gears, just as in a Formula One racing car.
Permanent all-wheel drive, the electronically controlled 4ETS traction system and ESP® team up to offer top-notch driving safety and keep the new R-Class safely on course, even in very bad road conditions. These systems all make up part of the vehicle’s standard specification, as does air suspension for the rear wheels. Mercedes customers also have the option of AIRMATIC all-round air suspension with the Adaptive Damping System ADS, which automatically lowers the suspension by 20 millimetres at high speeds to reduce wind resistance.
State-of-the-art safety features such as PRE-SAFE® and NECK-PRO head restraints
The latest technology offers passengers in the Grand Sports Tourer the safety to be expected of a Mercedes. PRE-SAFE®, the multi-award-winning anticipatory protection system which is available as an option, detects critical handling situations and immediately springs into action to prepare occupants and vehicle alike for an imminent collision. Precautions include pulling the driver’s and front passenger’s seat belts taut, adjusting the electrically adjustable front passenger seat with memory function to the optimum position and automatically closing the sliding sunroof. These preventive protection measures improve the seating position of the vehicle’s occupants prior to impact, thereby enhancing the restraining effect of the seat belts and airbags.
Adaptive front airbags and front sidebags as well as windowbags can all be found on the standard specification list of the new R-Class, and all passengers enjoy the added reassurance of belt tensioners and belt force limiters. A further Mercedes first for improving standards of occupant safety still further is NECK-PRO crash-responsive head restraints (optional).
Equipment: valuable extras in package form
The specially developed panoramic sunroof (optional), whose glass panels extend over virtually the entire surface of the roof, ensures a cooling supply of fresh air for the interior whilst letting in a pleasant amount of extra light, which all adds up to a matchless open-air motoring sensation for the occupants. The efficient air conditioning system makes long journeys aboard the new R-Class all the more comfortable. In addition to the standard-specification THERMATIC dual-zone climate control featuring a separate control panel for the rear, Mercedes-Benz is also able to offer a newly developed multi-zone THERMOTRONIC system as an option. Equipped with over a dozen sensors as well as an auxiliary booster blower, the system is able to faithfully maintain the temperatures set by the driver, the front passenger and the occupants in the rear.
A CD radio with eight loudspeakers, light-alloy wheels, speed-dependent power steering and front seats which are electrically adjustable for height, cushion angle and backrest angle are also included in the list of standard equipment. Mercedes-Benz offers a number of packages comprising quality extras for the new R-Class.
This allows customers to appoint and upgrade their Grand Sports Tourer to suit their personal taste. In addition to the AIRMATIC package, options include a styling package for the exterior and a sports package.
Model range and equipment: New dimensions
Being spontaneous, free and without ties. Packing one’s bags on the spur of the moment, for example, setting off into the great outdoors with friends and enjoying the drive there together – this is made possible by an innovative vehicle concept from Mercedes-Benz: the R-Class, the Grand Sports Tourer.
With its great versatility, the new model series mirrors an attitude toward life that the young and the young-at-heart are keen to express through the medium of the vehicle they drive. The R-Class combines the dynamism of a sporty saloon, the spaciousness and comfort of an MPV, the versatility of an estate and the poise and assurance of an off-roader.
The revolutionary Sports Tourer concept is the end product of customer interviews held all over the world. Mercedes-Benz has realised this innovative concept in the form of two model series: the B-Class, the Compact Sports Tourer, and the R-Class, which is available in two body variants as the Grand Sports Tourer:
For the USA, Europe and other markets Mercedes-Benz has developed a body with a wheelbase of 3215 millimetres. This has a length of 5157 millimetres, a width of 1922 millimetres and a height of 1661 millimetres.
The R-Class with a wheelbase of 2980 millimetres is intended for Europe and other regions. The body length is 4922, the width 1922 and the height 1659 millimetres.The three terms which describe the new Mercedes-Benz model leave no doubt as to where its main strengths lie:
Grand refers to its size, space and practicality: both versions of the R-Class offer considerably more room than many saloon models in the luxury segment. This translates into a completely new motoring sensation for passengers: an untrammelled experience of "space travel" on wheels.
Sports symbolises dynamism, high performance potential and a thrilling motoring experience: the two potent six-cylinder engines and the V8 power unit that are available for the R-Class span a power spectrum from 165 kW/ 224 hp up to 225 kW/306 hp. A seven-speed automatic transmission, permanent all-wheel drive, the 4ETS Electronic Traction System and ESP® all make up part of the standard package.
Tourer is a reference to this innovative new car’s outstanding credentials as a luxurious touring car: the new suspension system with standard-fitted air suspension at the rear, comfortable individual seats and automatic climate control gives it everything it needs for indulging its occupants with silky smooth comfort on long journeys. Standard specification list brims with high-tech for added safety and comfort
Equipment packages offer even greater scope for individuality
Further outstanding technical and appointments features are available by opting for one of the attractive equipment packages which allow Mercedes customers to inject their Grand Sports Tourer with even more individuality:
The AIRMATIC package consists of AIRMATIC air suspension combined with the ADS Adaptive Damping System.
The styling package includes the leather upholstery, electrically adjustable front seats, burr walnut wood trim, and a chrome package with door handles and side rub strips in the vehicle colour with chrome inserts, a silver/chrome-trimmed radiator grille and waistline trim strips. It also includes the interior lighting package, which adds features such as illuminated door handle recesses, illuminated air outlet thumbwheels, illuminated cup holders in the front and in the optional rear centre console, an illuminated stowage compartment in the transmission tunnel covering, plus reading lamps for the rearmost row of seats. An ambient /warning light is also integrated into the tailgate.
The sports package combines, among other things, 19" light-alloy wheels, size 255/50 R 19 tyres, chrome/silver radiator trim and blue-tinted glass all-round. Inside, the sports package comprises a specially designed instrument cluster, stainless steel sports pedals with rubber studs and electrically adjustable sports seats upholstered in Alcantara/ARTICO man-made leather. The decorative trim is in aluminium.
Design: The dream of space travel come true
A car with a length of around five metres which is able to offer first-class comfort for up to six passengers is very hard to overlook out on the road. Despite its generous dimensions, the Mercedes designers have successfully packaged the new R-Class in such a way that it appears both distinctively sporty and elegant - and therefore exudes agile light-footedness despite its size.
The design concept of the new R-Class is based on wide, sweeping proportions acting together with a long wheelbase and short overhangs. A prominent, arched roof line elegantly connects the A and D-pillars, making for an extended, coupé-like silhouette. The pronounced wedge-shape and muscular shoulders give the car additional dynamism and unmistakably assert its poised, assured character, producing an incomparable synthesis of generous interior space and sporty elegance.
The pronounced arrow-shape at the front of the new R-Class is a prominent feature. With a highly visible central ridge, this divides the bonnet area and continues down the radiator grille and into the centre section of the front bumper. In combination with the rising longitudinal lines it both communicates powerful forward motion and lends a lightweight impression to the front end.
The bonnet rises from the wings like a sculpture and reinforces the muscular presence of the front end. Markedly contoured surfaces, sharply defined edges and scalloped sides soften the basic lines, creating a three-dimensional effect and playing very effectively with light and shade. Flowing from the bonnet surface, the edges harmoniously blend into the A-pillars and combine the front end with the overall vehicle structure. A broad radiator grille dominates the typical Mercedes face of the new R-Class, creating a further sporty touch. It features three horizontal louvres of trapezoidal cross-section which are either painted silver or bear a chrome decorative strip, depending on the design and equipment line. The prominent radiator surround is another feature suggesting power and precision.
The bumper is very deep-drawn and visually lowers the centre of gravity - an effect reinforced by large air intakes in the bumper panelling. On the right and left these have silver frames housing the fog lamps, which resemble turbines and emphasise the width. A wing-like front spoiler defines the front end at the lower edge and gives the Grand Sports Tourer a four-square stance on the road surface. At the same time it reflects another interesting design theme of the R-Class, namely aerodynamics. The line drawn by the lower edge of the front spoiler is continued along the side skirts and extends into the rear end, where it ends in the rear diffuser surround as a counterpart to the front end.
The long, obliquely angled, elliptical headlamps lend this versatile and spacious vehicle its own identity. Arranged longitudinally, they visually shorten the length of the body and blend into the striking lines of the bonnet and wings. Additional side lights arranged inside complete this reinterpretation of the Mercedes look.
The crystal-clear headlamp lenses give a sense of lightness and brilliance, allowing a view of the powerful lighting technology of the new R-Class, which projects its beams onto the road from shining chrome cylinders.
The arched roof line is reminiscent of a coupé
The side view is heavily characterised by the arched roof line, which joins the A and D-pillars in a sweeping curve. It rises from the low line of the front end, long bonnet and swept-back windscreen and ends in the powerfully bulging tailgate. In this way the Mercedes designers have created a dramatically curving silhouette with flowing, coupé-like lines whose sporty elegance impresses despite the size of the car.
This is also assisted by the slight rearward rise of the lines in the flanks: from the front wheel arch to the rear lights, a pronounced shoulderline divides the side as-pect and creates a refractive edge between the concave and convex surfaces of the doors. As this line rises slightly towards the rear, it also accentuates the wedge-shape of the body - and therefore the dynamic and powerful character of the R-Class. At the rear end this line blends directly into the tailgate, emphasising char-acter and forward motion.
The extended window areas and high-gloss black door frames form a continuous surface and reinforce the impression of length. Depending on the design and equipment line, this is further underlined by chrome trim around the entire window area and contrasted by mirrors painted in the vehicle colour. Dynamic length is also suggested by the D-pillar, which tapers at the lower end and is supported at the lowest point of the window line to suggest an urge to leap forward.
Large wings and pronounced wheel arches with continuous chamfers direct the eye to the 17 to 19-inch light-alloy wheels, depending on the line. Their design has strong yet sporty contours, in line with the sporty all-wheel-drive character of the new R-Class. The side skirts are equally striking; they have a pronounced flare and are of aerodynamic design, thereby contributing to good tyre-to-road adhesion. At the same time they form another interesting refractive edge.
The design of the heavily curved rear end also shares the dynamically flowing lines which join the front and sides. The shoulderline rising toward the rear surrounds the rear light clusters and transfers its expressiveness to the tailgate. The rear light clusters appear to grow organically from the shoulder muscle, extend forwards considerably and thereby appear to shorten the body overhang. They feature round sections containing the reversing lights and indicators which form a clever design counterpart to the cylinders of the headlamps.
The design idiom of the exterior is continued in the interior
The power-oriented design idiom of the body’s styling, which is mainly based on an interesting contrast between convex and concave surfaces, has also been adopted in the interior by the designers. A harmonious synthesis of high-quality materials finished with the great attention to detail typical of Mercedes ensures a definite atmosphere of wellbeing in the variable interior, which offers up to six occupants an outstanding level of travel comfort.
The upper section of the dashboard extends across the entire width of the car like a central muscle, expressing in visual terms the performance potential of the new R-Class to the driver and passengers. This strong transverse emphasis is taken up again in the sporty four-spoke steering wheel with aluminium inserts in the lower two spokes, and is further emphasised by wood or chrome trim and a two-tone interior colour scheme. While the upper section of the dashboard, the soft armrests on the doors and the seat surfaces are in a dark colour tone, the remaining parts of the interior create an interesting contrast with a lighter shade of the same colour.
The driver’s eye falls on a sporty instrument cluster with large, round dials reminiscent of a high-quality chronograph, which are housed in slanted tubular binnacles to prevent reflections and ensure optimal legibility under all lighting conditions. The instruments feature fine chrome surrounds. Between them there is a two-section multifunction display - right in the driver’s field of vision.
Hand-finished materials such as wood, leather and aluminium please both the eye and the fingertips. Attention to detail and painstaking precision are to be found everywhere in the luxurious interior of the new R-Class.
Interior and comfort: A moving experience of inner freedom
Modern-minded people want plenty of space, effortless motoring, an extremely high degree of flexibility and the ability to use it whenever they feel like it - and the Grand Sports Tourer comes closer than any other vehicle to offering them exactly what they are looking for. But the R-Class has even more to offer in the interior. Anyone seated in one of the luxurious individual seats is immediately treated to a memorable experience: an untrammelled experience of "space travel" on wheels.
This new standard in travel does not just stem from the "XXL" dimensions of the interior. The R-Class offers far more besides, courtesy of a harmonious blend of factors that produce an uplifting sense of wellbeing: the smooth-running V6 or V8 engines, the flawless climate control, the pleasant acoustics, the air-sprung chassis, the appealing colour scheme, the high-grade materials - just a few of the features which combine to make travelling aboard the R-Class an unforgettable experience.
The challenge faced by engineers at Mercedes as they strove to create a vehicle concept that genuinely broke new ground started as early as the dimensional concept stage. The overriding question here was "How much car do six passengers need to enjoy Mercedes-class travel?". The answer was a car with a two-box design measuring 4922 and 5157 millimetres from front to rear. This makes the R-Class akin to a luxury saloon in size but considerably more spacious inside. All of which maximises freedom of movement, at the same time forming a linchpin of the vehicle’s supreme long-distance comfort. Several of the interior measurements simply speak for themselves. The seat spacing, one of the key indicators of freedom of movement and interior comfort, measures 860 or 920 millimetres between the first and second rows of seats in the standard position, a figure that is normally only associated with luxury saloons. The kneeroom is 119 or 175 millimetres, while the maximum seat spacing between the second and third rows of seats is 780 or 840 millimetres.
Headroom is another discipline in which the Grand Sports Tourer excels, with 1014 or 1027 millimetres available in the second row and 935 or 946 millimetres in the rearmost row of seats. The width measurements inside the R-Class also open up a whole new dimension in space and comfort, with the elbow width of up to 1550 millimetres in the front and 1562 millimetres in the rear eclipsing the figures for other luxury saloons by as much as 100 millimetres, representing a formidable result for the new vehicle concept.
Versatility is also high on the new model’s list of specialities: the individual seats in each of the rear rows can be folded flat separately as required, while the optional centre console can be removed completely, all in just a few simple steps. Thus equipped, the interior is able to mould itself to changing space requirements or to the transportation task in hand, making light work of carrying mountain bikes, skis, snowboards or any other recreational equipment items, for example. Even with a full contingent of six passengers on board, the R-Class still has enough space for a large golf bag behind the third row of seats.
With the rear seats folded down, the level load surface extends over a distance of 1980 or 2217 millimetres measured from the front seat backrests to the tailgate. The vehicle’s load capacity as measured using the VDA method also comfortably outstrips the figures for large estate cars, with a maximum of 1950 or 2385 litres when loaded up to roof height (in accordance with the VDA measuring method). Folding down just the third row of seats produces a luggage compartment with a maximum capacity of 888 or 1067 litres.
The seats can be rearranged to suit the current transportation task in just a few quick steps:
The head restraints in the second row of seats are first pulled out and placed on the seat cushions. Then, the backrests are tilted forwards and the entire seat unit is pushed downwards.
In the case of the third row of seats, the seat cushions are first raised to a vertical position, allowing the backrests to be folded forwards. The seat cushions can then be folded further forwards into a horizontal position. It is therefore the reverse faces of the two rear rows of seats which together form the level load compartment floor.
The driver’s and front passenger seats both feature power controls for adjusting the height, seat cushion inclination and backrest angle. Their fore/ aft adjustment range is 294 millimetres, allowing drivers of all statures to make themselves completely comfortable. The standard-fit facility for adjusting the steering wheel’s height and reach serves to make doubly sure that all drivers are able to find the sitting position that is best suited to them. The individual seats in the second row can also be manually repositioned fore and aft through a range of 150 millimetres, while the seats’ EASY-ENTRY function makes it simpler for passengers in the rearmost row of seats to get into and out of the vehicle.
The powerful design idiom of the body’s exterior, which stems predominantly from the striking contrast between its convex and concave-shaped surfaces, continues through into the interior of the vehicle. The top section of the dashboard cuts a muscular line from one side of the vehicle right through to the other, signalling power and performance capability as it does so. The two-tone interior colour scheme lends further emphasis to the pronounced crossways effect: the dark tone used for the dashboard, armrest and door panels forms an appealing contrast with the lighter tone variant sported by the remaining interior components. The tactile qualities are every bit as impressive too, thanks to the use of high-grade materials such as the fine leather on the armrests, the soft plastic surface of the dashboard, the aluminium or fine-wood trim and the switches in the centre console, whose faces gleam with a special "soft-touch" coating that has a particularly pleasant feel.
One of the most eye-catching features is the instrument cluster, whose large, round dials protrude from circular cylinders that are angled slightly inwards, while the black faces are a nostalgic touch that recalls the design of classic, high-precision chronographs. The left-hand cylinder houses the speedometer and clock, whilst the cylinder on the right keeps the driver informed of rev speed and fuel level. The various red and yellow indicator lamps that are distributed over the surface of the two dials only ever make their presence known when the engine is started or they are prompted to light up.
Nestling in-between the two dials is a split central display, showing the distance travelled at the top and the current drive mode, selector lever position and outside temperature at the bottom. At the press of a thumb, the buttons in the standard-fit multifunction steering wheel give drivers control over the stereo system and car phone, as well as allowing them to call up important information, which again appears in the instrument cluster’s central display. This also provides a convenient means of programming individual settings, covering everything from the digital km/h display and activation of the automatic central locking to setting the speed limit for winter tyres. Once these settings have been made, they remain permanently activated and require no further intervention on the part of the driver.
The Mercedes engineers have made the interior door trim an integral part of the operating concept, too, incorporating into it the controls for the standard-specification power windows, the exterior mirror adjustment and the remote tail-gate release (driver’s door).
The units and controls in the centre console are arranged in accordance with ergonomic principles, with the relative importance of the functions, the frequency with which they are used and visual considerations taking priority. Consequently, the car stereo system or navigation system, depending on the model’s specification, is located in the topmost position, where it is both prominent and within easy reach of the driver. Below this can be found the control panel for either the THERMATIC automatic climate control system that is fitted as standard or for the optional multi-zone THERMOTRONIC system, with both units featuring ergonomic, attractively styled rotary controls for manually adjusting the temperature (right). Rounding off the centre console at the bottom is an array of buttons for controlling various functions.
Dispensing with a conventional automatic transmission selector lever in favour of the brand new DIRECT SELECT gearshift on the steering column has made way for a roomy stowage compartment and a cup holder in the transmission tunnel covering of the R-Class. Both are concealed beneath covers which gently open when light pressure is applied. The padded armrest between the front seats also conceals a spacious stowage compartment, with a special section at the top where a mobile phone can be installed. The back of the transmission tunnel covering features two individually adjustable air outlets for the rear compartment.
Audio 20 car radio system with CD player fitted as standard
The Grand Sports Tourer rolls off the production line equipped with the Audio 20 stereo system as standard, ensuring excellent in-car entertainment and pure musical listening pleasure. It features an FM/MW/LW/SW tuner combined with an integral CD player. The unit also boasts a keypad which can be used to enter phone numbers when it is networked with a car phone or mobile phone.
There is a choice of two optional combined tuner and navigation systems for the new R-Class:
The Audio 50 APS unit comprises a twin FM tuner, CD player, TFT colour display and arrow-directed navigation. The integrated CD player can continue to play audio CDs whilst navigation is in progress. All other radio and control functions are identical to the Audio 20 unit.
The hallmark feature of the COMAND APS system is its large 6.5" colour display featuring state-of-the-art TFT technology. A full-colour map assists with route guidance. Once the route has been computed, the navigation DVD can be removed to allow audio CDs to be played, in which case the navigation system will issue its instructions in the form of arrows. Radio reception is taken care of by a twin FM RDS tuner which is also able to receive LW, MW and SW stations.
All of the Mercedes car radio systems include a speed-sensitive volume control: above a speed of around 20 km/h, the volume is raised in increments to compensate for the increase in background noise. An antenna diversity function, which ensures optimum reception by selecting the strongest signal from the roof aerial and the two FM aerials in the rear window, also makes up part of the standard package.
Sound system and DVD system for superlative in-car entertainment
The Mercedes car stereo systems channel their output through a total of eight speakers as standard. An even more sophisticated set-up is available in the form of a surround sound system boasting eleven speakers in all, plus an extra sub-woofer. The system has been custom-designed to suit the interior’s acoustics: a microphone monitors current noise levels, enabling a microcomputer to adapt the volume and sound accordingly to ensure uninterrupted high-fidelity listening. A six-disc, MP3-compatible CD changer which is housed in the glove compartment may also be specified as an option in conjunction with the Audio 20, Audio 50 APS and COMAND APS systems.
A further equipment option allows passengers in the rear to enjoy the freedom of compiling their own audio or video entertainment programme. The Rear-Seat Entertainment package comprises two colour screens with earphone connections which are incorporated into the backs of the front-seat head restraints, along with a CD/DVD player which is accommodated in the rear centre console. There is also a facility for connecting external audio/video devices or a games console.
Choice of two sensor-regulated air conditioning systems
Climate control for such a spacious interior as that in the R-Class is reliant on powerful technology. Mercedes engineers have devised two different systems which are designed to offer supreme passenger comfort:
In standard specification, the R-Class comes equipped with the THERMATIC system that provides dual-zone interior climate control.
Customers may also opt for the multi-zone THERMOTRONIC system which permits individual temperature settings to be made for three separate zones: for the driver’s side, for the front passenger side and for the passengers in the second row of seats in the rear.
The multi-zone THERMOTRONIC system can in turn be expanded by the addition of a rear air conditioning unit for the third row of seats. This unit is concealed in the rear behind the left-hand sidewall panelling.
Both systems have been adapted to take account of the generous interior dimensions of the new R-Class, resulting in exemplary efficiency. They are equally as capable of cooling down the interior quickly on hot summer days as they are of keeping passengers snug and warm in the depths of winter. The automatic climate control’s maximum heating capacity, for example, as measured in accordance with test specifications in ambient air that has been cooled down to minus 20 degrees Celsius and at a coolant temperature of 80 degrees Celsius, is ten kilowatts. To put this figure in perspective, it roughly equates to the capacity of a modern central heating system in a detached house.
On the R 320 CDI diesel-powered model, the effect of the heater core is boosted at low outside temperatures by an electrical PTC (Positive Temperature Coefficient) heating element with a heating capacity of 1.7 kilowatts. The PTC’s additional heating power is required as a result of the six-cylinder CDI engine’s outstanding thermal efficiency, which has an extremely positive impact on fuel consumption but results in far less heat being dissipated to the coolant at partial throttle than is the case with many other engines.
Sensors regulate operation of the THERMATIC automatic climate control system to take account of temperature changes and levels of direct sunlight. The system is controlled by a network of nine sensors in all: seven outflow pickups in the air outlets monitor the temperature of the air as it enters the interior, one sensor in the control panel records the interior temperature and a solar sensor on the dashboard relays data on the intensity of the sunlight and its angle of incidence. This provides all the information that is required to compare the passengers’ desired settings with the actual readings and adjust climate control accordingly. This means that in automatic mode, the temperature, blower speed and air distribution are permanently regulated in such a way that the temperatures set by the driver and front passenger are faithfully maintained once they have been reached. At high ambient temperatures, for example, the automatic climate control is also capable of varying the proportion of recirculated air: this has the dual effect of cooling down the passenger compartment more rapidly and of minimising the required cooling output.
To keep THERMATIC running as economically as possible by adapting its operation to current requirements, the powerful air conditioning compressor is able to adjust its output smoothly. This is done by means of a solenoid valve which varies the compressor’s swept volume.
The driver and front passenger are each able to select their preferred temperature using stylish rotary controls. Red LEDs indicate the temperature settings. The right-hand control also includes buttons for activating the rear compartment ventilation and residual engine heat utilisation functions. In the centre of the panel between the two temperature controls can be found buttons for manually setting the blower speed, switching on the defrost function, the heated rear windscreen and air recirculation mode, as well as for altering the air distribution settings.
Passengers seated in the second row benefit from their own control panel. Located on the rear of the transmission tunnel, it allows air distribution to be adjusted individually for each of the second-row seats.
Multi-zone THERMOTRONIC with booster blower for the rear
The optional multi-zone THERMOTRONIC system offers an even higher standard of climate comfort, which is especially of benefit to passengers in the rear. To achieve this, Mercedes-Benz devised the principle of three-zone climate control, whereby the occupants in the second row of seats are able to select their own temperature, airflow and air distribution settings independently of the driver and front passenger. This is all made possible by the inclusion of an auxiliary booster blower in the transmission tunnel covering, which permits virtually autonomous control over the airflow in the rear.
A team of eleven sensors keep the multi-zone THERMOTRONIC system’s microcomputer fed with up-to-the-minute readings: the seven outflow temperature pickups in the air outlets, the central temperature sensor in the control panel and the solar sensor are joined by a dew-point sensor whose air humidity readings are also used to automatically regulate climate control. Finally, the multi-zone THERMOTRONIC system in the new R-Class also comes equipped with a pollutant sensor which monitors levels of carbon monoxide and nitrogen oxides in the outside air. If the concentration of pollutants becomes too high, the air conditioning automatically switches over into air recirculation mode. In the system’s fresh air mode, an activated charcoal filter works to absorb pollutants and reduce the intensity of any unpleasant odours penetrating the passenger compartment.
LEDs in the stylish rotary controls on the front of the multi-zone THERMOTRONIC control panel keep the driver and front passenger informed of the current temperature settings. The "Mono" button in the left-hand control enables the settings for both the driver’s and front passenger side, as well as for the rear, to be synchronised and temperature selection to be controlled centrally using the left-hand rotary control. If the R-Class leaves the production line equipped with multi-zone THERMOTRONIC, the interior linings of the B-pillars are also fitted with movable air vents directed to the rear.
Powertrain: Dynamism as standard
The outputs of the engines available for the R-Class range from 165 kW/224 hp to 225 kW/306 hp. They include two smooth-running petrol units with six and eight cylinders and the new V6 diesel engine by Mercedes-Benz - a powerful trio which provides optimal conditions for dynamic driving pleasure and a high level of long-distance comfort.
This is borne out by the performance figures for the Grand Sports Tourer:
Acceleration: The top-of-the-line V8 model R 500 requires just 6.9 or 7.0 seconds to sprint from standstill to 100 km/h, thereby putting many a sporty saloon firmly in the shade. The R 350 accelerates to 100 km/h in 8.3 or 8.4 seconds and the R 320 CDI requires 8.7 or 8.8 seconds.
Maximum speed: The maximum speed of the R-Class is 245 km/h (R 500). The R 350 and R 320 CDI have a top speed of 230 and 222 km/h respectively.
Flexibility: The exemplary torque characteristics of the engines and their perfect interaction with the 7G-TRONIC seven-speed automatic transmission make themselves felt during an intermediate sprint from 60 to 120 km/h. The figures: 6.6 or 6.7 seconds for the R 500, 8.1 or 8.2 seconds for the R 350 and 8.7 or 8.8 seconds for the R 320 CDI.
Fuel consumption: In this area too, the engines in the R-Class show that they are among the most modern high-tech units. In the EU driving cycle the six-cylinder diesel in the R 320 CDI consumes 9.3 litres of fuel per 100 kilometres, while the V6 petrol-engined R 350 requires 11.4 or 11.5 litres to cover 100 kilometres and the eight-cylinder of the R 500 requires 13.3 litres of premium unleaded (all figures: combined consumption).
R 320 CDI: V6 diesel with outstanding output and torque
With 165 kW/224 hp the V6 engine in the R 320 CDI is among the most powerful six-cylinder diesel units in this displacement class. This newly developed engine also generates outstanding torque: 510 newton metres are already available from 1600 rpm.
The six-cylinder unit is equipped with third-generation common-rail direct injection. This means that the injectors, high-pressure pump and electronic engine management operate even more efficiently, further reducing fuel consumption, exhaust emissions and combustion noise. Instead of the previous solenoid valves, the injectors are equipped with piezo-ceramics whose crystalline structure changes within microseconds under an electric voltage. The engine developers used this effect, which was discovered in 1880 by the brothers Pierre and Jacques Curie, to lift the needle jet at the tip of the injector with a precision of mere thousandths of a millimetre and thereby achieve an extremely fine jet of fuel.
Moreover, piezo injectors are considerably lighter and operate at twice the speed of conventional solenoid valves. With a response time of only 0.1 milliseconds, the fuel injection process can be even more precisely suited to the current load and engine speed situation, with favourable effects on emissions, fuel consumption and combustion noise. The number of fuel injections per power stroke is increased from three to five thanks to this piezo technology.
Mercedes engineers have also made improvements to other components of the common-rail system and the injection process:
The hydraulically optimised injector nozzles have eight holes (previously seven), which ensures even finer distribution of the fuel within the combustion chamber and more efficient mixture formation.
The inlet-metered high-pressure pump operates with a maximum injection pressure of 1600 bar.
The pilot injection process developed by Mercedes-Benz, which ensures a smoother combustion process and thereby audibly reduces the operating noise of the engine, takes place twice in succession in the new V6 engine. Small pilot quantities of fuel are injected within less than a millisecond and preheat the combustion chambers even more efficiently.
To burn off the soot particles in the particulate filter, there is a double post-injection of fuel when required. The new V6 diesel engine is aspirated by a VNT (Variable Nozzle Turbine) turbocharger. This technology enables high levels of output and torque to be achieved even at low engine speeds. The electrically controlled VNT turbochargers are able to vary the angle of their turbine blades rapidly and precisely to suit the operating status of the engine, and can therefore use the largest possible volume of exhaust gas to compress the intake air and build up charge pressure. More efficient cylinder charging and therefore higher torque are the results of variable, demand-related turbocharger control. Moreover, electric VNT technology allows a precise interaction with other units which are responsible for reducing untreated emissions and for exhaust gas aftertreatment.
The turbocharger is combined with a downstream intercooler which reduces the temperature of the compressed, heated air by up to 95 degrees Celsius, allowing a larger volume of air to reach the combustion chambers. Behind the intercooler there is an electrically controlled flap which enables the V6 engine to be throttled back precisely when the exhaust gas recirculation is in operation. This electrically regulated control flap allows the volume and mix of the exhaust gases added to the combustion air to be very precisely metered. To optimise the volume of recirculated exhaust gas, it is abruptly cooled in a high-performance heat exchanger. Acting in conjunction with the hot-film air mass sensors integrated into the intake air ducts, which provide the engine control unit with precise information about the current volume of intake air, this significantly reduces nitrogen oxide emissions. The combustion air then flows into the charge air distribution module, which supplies each cylinder in equal measure. The distribution module features an integral, electrically controlled intake port shut-off function with which the intake port cross-section for each cylinder can be variably reduced. This modifies the swirl of the combustion air, ensuring that the charge flow to the cylinders is adjusted for the best possible combustion and exhaust emissions under any load and engine speed conditions.
Emission control with two catalytic converters and a particulate filter
Two oxidising catalytic converters clean the exhaust gases emitted by the new Mercedes diesel engine. One acts as a primary catalytic converter, and is ready for action very soon after a cold start thanks to its position close to the engine. This unit is accompanied by a downstream main catalytic converter. The purpose of the oxidation-type catalytic converters is to convert carbon monoxide and unburned hydrocarbons by combining them with oxygen to form chemical compounds (oxidisation). This efficient exhaust gas aftertreatment combined with the complex in-engine measures already enables the V6 diesel engine to meet the stringent EU4 exhaust limits. To lower exhaust emissions even further, Mercedes-Benz combines the new six-cylinder powerplant with a maintenance-free particulate filter.
Mercedes-Benz has developed the first V6 diesel engine made of aluminium
As a world first, Mercedes-Benz has developed a six-cylinder diesel engine with an aluminium crankcase and cast-in grey iron cylinder liners. It tips the scales at just 41 kilograms. Aluminium is also used for the cylinder heads, cylinder head covers, pistons, coolant pump, sump and charge pressure distributor. Plastics are also used to save weight. Components in the fresh and charge air ducting systems, damper filter and engine shrouding are of plastic.
A likewise newly developed valvegear reduces both friction and moving masses: the 24 intake and exhaust valves are controlled by an overhead camshaft for each cylinder bank, via roller-type cam followers with hydraulic valve clearance compensation. The camshafts are driven by a tried-and-tested double-bush timing chain system into which the balancer shaft and the high-pressure pump for the fuel injection system are integrated.
R 350: the new six-cylinder engine has an output of 200 kW/272 hp
Output, torque, fuel consumption, comfort and exhaust emissions - these were also task areas of equal importance when developing the new V6 petrol engine. This up-to-date six-cylinder unit makes its mark in each of these disciplines. The interaction of the 24 valves can be controlled as required - depending on the engine load - by continuous, variable camshaft adjustment. This ensures an extremely rapid gas exchange in the cylinders. 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.
This valve overlap when venting the exhaust gases and taking in the fresh mix-ture makes an efficient internal exhaust gas recirculation possible. This reduces the energy losses during the charge cycle in the cylinders, leading to a signifi-cantly lower fuel consumption. Under higher engine loads the camshaft adjustment feature is also used to optimise the valve overlap in line with the engine speed so that the combustion chambers are efficiently supplied with fresh mix-ture – which makes for a high power and torque output.
An intake module produced in well-proven magnesium technology enables the air intake to be varied according to the engine load and rev speed. The length of the intake pipes leading to the cylinders is varied by means of flaps: at high engine speeds – from approx. 3500 rpm – the flaps are open and the air takes the shortest distance to reach the combustion chambers, producing a high engine output. At low engine speeds the flaps are closed, increasing the length of the intake duct. This creates pressure waves which assist the intake process and fundamentally improve the torque generated in the lower engine speed range. No less than 305 Newton metres are already available from 1500 rpm, which corresponds to about 87 percent of the maximum torque.
Tumble flaps in the intake ducts improve combustion
Electro-pneumatically driven flaps at the end of each intake duct are the special feature of the intake module in the Mercedes six-cylinder engine. These make a significant contribution to fuel economy. Mercedes engineers refer to these as tumble flaps, which in some measure indicates their purpose: they literally cause the fuel/air mix to tumble, increasing the turbulence of the airflow and causing it to enter the combustion chambers at higher speed, with a more uniform distribution. The result is better, more complete combustion.
At part-throttle, the tumble flaps pivot upwards, optimising the airflow and in-creasing the speed of combustion – a benefit that makes itself particularly notice-able where the mixture is lean as a result of exhaust gas recirculation and which further reduces fuel consumption. Under higher engine loads the tumble flaps are not required, and can be completely recessed into the intake manifold so as not to impede the intake process. By virtue of the tumble flaps in the intake ducts, the engine’s fuel consumption can be reduced by up to 0.2 litres per 100 kilometres depending on engine speed - while improving smoothness at the same time.
Emission control using in-engine measures and catalytic converters
The emission control system follows a two-stage concept: it is based both on so-phisticated engine-specific measures for a reduction in untreated emissions and on highly effective emission control using two catalytic converters located close to the engine. Each of these is equipped with two oxygen sensors - a control sensor and a diagnostic sensor - with linear control. This means that the oxygen sensors are already active immediately after a cold start, supplying information about the exhaust gas constituents for the electronic engine management system to process when controlling the warm-up phase. The engine-specific measures include for example variable camshaft adjustment, which makes efficient internal exhaust gas recirculation possible under partial load. A secondary air injection system is also used.
R 500: V8 engine offers outstanding comfort and excellent performance characteristics
The V8 engine in the new R 500 generates 225 kW/306 hp from a displacement of 4966 cubic centimetres. An electronically controlled intake module increases the torque available at low engine speeds and ensures that on both town and country roads, the engine is always able to respond immediately to the driver’s power requirements. More than 400 Newton metres are already available from 2000 rpm, corresponding to almost 90 percent of the maximum torque of 460 newton metres which the eight-cylinder unit places on tap at 2700 rpm and maintains up to 4750 rpm.
DIRECT SELECT perfects the operation of the seven-speed automatic transmission
On board the new R-Class, the powerful six and eight-cylinder engines and the 7G-TRONIC seven-speed automatic transmission form a strong team. With a number of special technical features, this transmission fully exploits the characteristics of the engines and therefore makes a major contribution to brisk acceleration, rapid intermediate sprints, a favourable fuel consumption and a high level of gearshift comfort.
The 7G-TRONIC transmission has a further special feature: DIRECT SELECT. This means that the conventional automatic selector lever in the centre console is replaced by a lever on the steering column, which the driver nudges to select the transmission settings "P", "N", "R" and "D". Operating commands are transmitted electronically by wire, which is why the system is referred to as "shift-by-wire". For drivers with sporty inclinations who wish to operate the transmission manually in certain driving situations, the new R-Class can be equipped with steering-wheel gearshift buttons as standard.
Permanent all-wheel drive and 4ETS as standard
The transfer case for the permanent all-wheel drive system is directly flanged to the 7G-TRONIC transmission. Torque distribution between the axles is 50:50. Propeller shafts transfer power to the front and rear axles, while a bevel differential compensates the speed of rotation between the axles.
Traction control is provided by the well-proven 4ETS Electronic Traction System, which now has additional functions and is even more capable than before. 4ETS controls the distribution of torque to the wheels by triggering brief braking pulses based on the signals received from the ABS wheel sensors: if these sensors report that one or more wheels have lost their traction, they are automatically braked. At the same time the distribution of drive torque is changed: the torque fed to the wheels with good traction is increased in line with the braking effect on the spinning wheels, allowing progress to continue on loose or slippery surfaces.
Suspension: Floating on air
A wide track, a long wheelbase and newly developed axles - these factors ensure that the R-Class meets even the highest expectations where both handling dynamics and ride comfort are concerned. The front wheels are located by a newly developed double-wishbone suspension with a high-mounted upper wishbone. This is made of forged aluminium, while the lower wishbone and steering knuckle are of nodular cast iron. The front axle, steering gear, engine and transmission are mounted on an integral subframe of high-strength sheet steel.
This front suspension with its high control arms is equipped with spring struts with a long spring travel and highly effective rubber mounts. The spring struts contain cylindrical coil springs, single-tube gas-pressure shock absorbers and large upper bearings. The torsion bar stabiliser is attached to the spring strut by a linkage.
The steering gear of the new R-Class is positioned in front of the wheel centre, and therefore where it can support the slight but easily controlled understeer on bends. The servo-assisted rack-and-pinion steering has a variable ratio which operates a little more directly in the central position than in the outer positions. Additional comfort is provided by the standard-fit speed-sensitive power steering, which, at speeds below 100 km/h, adapts the steering effort as a function of vehicle speed. This is made possible by an electronically controlled valve: the lower the speed, the higher the servo effect. Accordingly only half the steering effort is required when parking the vehicle as when driving on the motorway, where the speed-sensitive power steering provides a good feeling of road contact.
Mercedes-Benz has developed a reach and height-adjustable four-spoke steering wheel with a diameter of 385 millimetres for the new R-Class whose die-cast magnesium structure is designed to deform specifically during a frontal collision, thereby reducing the risk of injury to the driver. The steering wheel is an important part of the operating and display concept with its conveniently placed, illuminated buttons, as it allows various functions such as the radio, car telephone or the central display in the instrument cluster to be operated by slight thumb pressure. The newly developed steering column collapses telescopically by up to 82 millimetres in the event of a frontal collision.
The four-link rear axle of aluminium and forged steel
The rear axle is mounted on a subframe which is effectively isolated from the bodyshell by four rubber mounts. Mercedes engineers have developed a four-link suspension design which basically consists of the following elements:
Track rods: These are located behind the wheel centre and are of welded tubular construction.
The four-link rear axle is equipped with air suspension, separate single-tube shock absorbers and a torsion bar stabiliser.
AIRMATIC air suspension automatically lowers the body from 120 km/h
The AIRMATIC air suspension system (optional) developed by Mercedes-Benz not only offers significantly improved ride comfort, but also improves the aerodynamics and therefore fuel consumption at higher speeds. The system operates on a speed-dependent basis and automatically lowers the ride height by 20 millimetres when 120 km/h is reached. When the speed falls below 60 km/h the body is raised to its normal level again.
At the touch of a button the driver is able to raise the ride height by a maximum of 50 millimetres, in order to obtain more ground clearance, for instance when driving on rough tracks. AIRMATIC lowers the body to its normal level when the speed reaches 40 km/h. Other features of the air suspension system include an automatic all-round level control function, which ensures that the suspension travel remains constant even when the vehicle is heavily laden.
ADS adjusts the shock absorbers to suit the driving situation
AIRMATIC works as standard in tandem with the Adaptive Damping System (ADS), which controls the shock absorber response in line with requirements while taking the road surface, driving style and load into consideration. Selectable solenoid valves in the shock absorbers enable the rebound and compression damping to be modified according to the situation, which considerably reduces body movements. A "skyhook" algorithm controls the damping forces at each wheel in such a way that the wheel-induced forces acting on the vehicle body are reduced. Thanks to this precise control for each individual wheel, the two front wheels can for example be damped more heavily than the rear wheels to reduce the tendency of the body to dive when braking. Depending on the control command, the valves are able to select one of four sets of response characteristics within an extremely short response time of less than 0.05 seconds:
- Stage 1: Comfortable suspension action with small body movements and low acceleration values owing to soft compression and rebound settings.
- Stage 2: Skyhook mode - soft rebound setting and a hard compression setting.
- Stage 3: Skyhook mode - soft compression setting and hard rebound setting.
- Stage 4: Hard rebound and compression setting to reduce wheel load fluctuations when cornering at speed.
When body movements are small the new R-Class operates in ADS stage 1. If body acceleration values exceed a certain level, the system changes over to the skyhook algorithm and uses its rapid-response solenoid valves to continuously switch between the second and third damping stage to compensate the rolling and pitching movements of the vehicle body. In addition the driver is able to influence the changeover thresholds between the four ADS stages, as well as the spring rate, by pressing a button in the centre console. There is a choice of three modes: "Auto", "Sport" and "Comfort".
The variable ADS gas-pressure shock absorbers and air spring are integrated into a spring strut at the front axle of the new R-Class. At the rear axle the ADS shock absorber is located behind the air spring. Torsion bar stabilisers are also used at both the front and rear.
The R 500 is equipped with four internally ventilated disc brakes
The Grand Sports Tourer is equipped with efficient, internally ventilated front brake discs with a diameter of 330 millimetres in the six-cylinder models. In the R 500 their diameter is 350 millimetres. At the rear axle Mercedes -Benz uses solid disc brakes with a diameter of 330 millimetres, and in the R 500 these too are internally ventilated.
ESP® with tyre pressure loss warning function
ABS, ASR, ESP®, Brake Assist - these well-proven dynamic safety systems devel-oped by Mercedes-Benz are standard equipment in the new R-Class. In its latest version, the Electronic Stability Program also monitors the tyre pressure: the system continuously compares the wheel rotation speeds, which mainly depend on the vehicle speed, vehicle load and tyre pressures. It is therefore able to detect any significant deviations. In addition the control unit automatically monitors other dynamic parameters such as the lateral acceleration, yaw rate and wheel torque in order to diagnose any pressure loss in a tyre reliably, though this system does not measure the actual air pressure in each tyre. If a loss of pressure is detected in a tyre, a warning appears in the cockpit’s central display: "Tyre pressure, check tyres." This warning function for tyre pressure loss based on ESP® technology is standard equipment in the new R-Class.
An optional electronic tyre pressure monitoring system is also available; it uses sensors in the tyre valves to monitor both the air pressure and temperature inside the tyre. The data are transmitted by radio to special antennae in the wheel arches which are linked to a microprocessor. This distinguishes between the signals on the basis of their individual signature, and is therefore able to provide the driver with specific information about the air pressure in each of the four tyres via a cockpit display.