In a rapidly changing market influenced by ever more demanding consumers, Peugeot launched the 407, its saloon in the “middle to upper” segment.
The 407 saloon, which was rapidly followed by an SW model, is the first member of the new 407 family responsible for carrying forward Peugeot’s key values – Dynamism,Value for Money,Visual Appeal – and Innovation.
This market segment has immense strategic importance for a mainstream manufacturer and, for decades the famous “4” series vehicles have played a key part in Peugeot’s history. The 407 saloon is a worthy successor to the 406 saloon and paves the way for a new page in Peugeot’s history.
Historically, saloon customers in the M2 segment are attracted by the marque’s motoring pedigree when viewing models in this sector.While not wholly convinced of the merits of a larger saloon in the H segment, they nevertheless seek some of the benefits offered in terms of comfort and technology. Additionally, many also seek the dynamism offered in smaller cars – an area where Peugeot has always excelled.
The Peugeot marque is synonymous with dynamic performance, safety and driving pleasure – characteristics common to all the models regardless of their individual personality. Dynamically, the 407 is a worthy successor to the 406, a model with road-holding characteristics that still serve as the benchmark for its era.
Drawing on experience and specialist know-how, Peugeot has conceived and put together a highly efficient specification that covers all aspects of ride and handling.The performance levels resulting from selected technological features, specially adapted to the 407, are designed to provide instantly perceptible driving pleasure and exemplary active safety under all circumstances, without in any way compromising driver and passenger comfort.
This specification consists of axles that make extensive use of lightweight aluminium alloy for enhanced performance:
- front axle with double wishbone and a linked hub carrier offering a superb road holding and comfort, combined with excellent directional control.
- multi-arm rear suspension with dampers inclined rearwards to optimise the width of the boot
Active safety on the 407 is of a high level and benefits from large disc brakes with a diameter up to 330 mm and a new generation ESP, which is present on all versions.The latter comprises an anti-skid function, ABS, emergency brake assist, new individual wheel brake force distribution, and a stabilit control system with particularly efficient correction of under- and over-steering.
Automatic activation of hazard warning lights in the event of sharp deceleration informs following vehicles of potential danger.
The exclusive V6 engine To accompany its pedigree and performance, the V6 engine has unique suspension and steering that offer outstanding performance levels.The variable damping has four independentlycontrolled dampers with nine distinct settings absorption patterns, while the car also benefits from vehicle speed variable rate power steering.
The 407 adds a new dimension to the Peugeot brand, and introduces a car rich in dynamism and elegance.A clear commitment to innovation marks Peugeot’s entry into a new style era.
The exterior styling of the 407 has a distinct feline grace, with a distinguished look at the front, revealing a new Peugeot identity based on a unique air intake grille and generously dimensione headlamps. Peugeot’s stylists have achieved balance through the long bonnet and the compact rear proportions that project the passenger cabin forwards.
Fluid lines are a characteristic feature of the car.The front windscreen pillar, steeply inclined and occupying a very forward position over the front axle, merges seamlessly into the bonnet.
It marks the beginning of the harmonious curve of the roof, which sweeps back to the vehicle’s rear quarter panel.
The side aspect of the 407 has uncluttered, taut lines and possesses a flange that runs the entire length of the car, creating the appearance of strength.
At the rear, the design of the wings and the spoiler creates a sporty feel that in no way detracts from the car’s natural elegance.The inset rear window is reminiscent of that of a coupe.
4.676 m of verve and looks "that purr"
At first sight the new 407 stirs the emotions, thanks to the new, elegant, feline balance of its appearance.
Its highly evocative front aspect retains the big-cat feel, but also features an air intake shaped like an open mouth and a prominent badge – two strong design features that mark a new stylistic approach for the Marque. The profile evokes the posture of an animal ready to pounce.Resting on large-diameter wheels, the aluminium bonnet and immense windscreen, are the precursors of “muscles” that span the vehicle’s length to its short and powerful rear aspect.
The overall effect is one of power, strength and security, combined with a promise of exceptional dynamic performance.
Some architectural features The 407 is based on the design platform of middle and upper segment PSA Peugeot Citroën vehicles.The specification has however been updated significantly to meet Peugeot’s distinctive requirements for road-holding, driveability and safety. Its overall size places it in the middle of its segment.
The exterior of the 407 is available in 12 colours that emphasise its refined elegance and give the car a variety of personalities.
At the heart of its segment, the 407 has the generous, balanced proportions of a stately yet dynamic car, with an overall length of 4.676 m in saloon form and 4.763 m as an SW.
Up to the rear axle, the 407 saloon and 407 SW share the same length :
a front overhang of 1,029 mm giving occupants and pedestrians greater protection against impacts
a wheelbase of 2,725 mm
After this, the distinguishing features are :
a rear overhang of 922 mm for the saloon (1,010 mm for the SW for ease of access to the luggage compartment - very low sill, tailgate curving generously in the upper part, original design of rear quarter panels which has allowed important structural reinforcement)
an overall height of 1,445 mm for the saloon (1,486 mm in the SW thanks to the new roof design and the use of longitudinal roll bars)
Architecture - structure
The structure of the 407 uses the platform from the middle and upper segments of PSA Peugeot Citroën ranges. It has however been adapted to meet the ambitious requirements of this new car, particularly in terms of driving dynamics and safety.
The body exhibits a torsional rigidity – 0.77 mrd under a torque of 100 daN.m – never before attained on a Peugeot saloon.This high rigidity ensures the optimum performance of the suspension and enhances road holding and active safety, as well as driving dynamics and comfort.
In addition, special attention has been given to the front structure to improve passive safety.Here, a new lower structure absorbs forces and adds its benefits to the “classic” top structure made up of the chassis legs. Two thirds of the energy is absorbed via the top structure and one third via the bottom structure.
This bottom structure consists of a long sub-frame, made up of a standard sub-frame with the addition of extensions, a front crossmember, absorbers and a pedestrian beam covered by impact absorbing foam.
With the exception of the pedestrian beam, all parts of the long sub-frame are manufactured from aluminium.This front structure represents a new strategy of impact absorption.
By creating better distribution of forces it combines the attractive features of a car rigid enough to offer protection in the event of a high-speed front impact, while at the same time supple enough to offer protection to pedestrians and ensure compatibility in collisions with lighter vehicles.
A device, known as the ‘impactor’, anchors the engine to the sub-frame, and completes the protection against high-speed front impact by limiting the intrusion of the engine into the passenger compartment.
Pedestrian protection is ensured by the structural suppleness of the front of the car and by means of shock absorbing foam padding fitted to the lower part of the pedestrian beam - the final element of the bottom structure, and to the top of the bumper bar.
Finally, the bonnet limits the effects of this type of impact even further, since its rigidity, and its distance from the mechanical components it houses, have been optimised to reduce head injuries.
Repairability also benefits considerably from this design, which is optimised by a removable front section to the long sub-frame, a bolted end beam on the front chassis leg and, at the rear of the car, a bolted composite beam protecting the rear panel. Protection against side impact is ensured by the design of the body frame and superstructure, which absorbs energy and preserves a survival cell for all occupants.
The doors are equipped with “Omega” strengtheners, and tubular bars at the front enhance rigidity by creating a solid span between the ‘A’ posts and B/C posts and the rear wheel arch.
The complete weight of the structure with windows, paintwork and noise insulation has been limited to 372 kg .Much work has been devoted to optimising the aerodynamic qualities of the 407, which has a drag coefficient or Cx of 0.29 versus 0.32 for the 406.
With a front surface area of 2.23 m2 versus 2.08 m2 for the 406, the 407 has an SCx of 0.64, an improvement compared to the 406 (SCx: 0.65), which was narrower by 46 mm, lower by 33 mm and was equipped with smaller wheels than the 407.
These results were obtained thanks largely to the overall fluidity of style, with localised enhancements (lower front panel and tailgate), significant under body shielding, and the seamless styling of the front of the vehicle. The structure of the 407 is guaranteed for twelve years against corrosion of any kind, while paintwork comes with a three-year warranty.
The interior reveals a bright and spacious driver’s compartment. The characteristic dual-arch design gives the fascia panel character, beginning its sweep at the base of a perfectly structured central console.The forward position of the windscreen creates a feeling of airiness and light that reinforces the notion of space and protection.
The seats are designed for comfort, and their wrap-around design provides excellent support to the shoulders and legs.
The eye is drawn immediately to the natural and elegant curves of the interior that create a sense of calm and serenity in the passenger compartment. Following the example of the exterior lines, the interior of the 407 exudes strength and quality.
Structured around a central console and a dual-visor fascia panel, the interior is organised to ensure that everyone can enjoy driving and travelling together. Its finish is designed to evoke the same dynamism of the exterior and utilises materials that offer supreme comfort.
Open to the light …
The brightness of the interior is striking, with light diffused through almost 1.5 m2 of windscreen and the long side windows. The latter afford rear passengers an unbroken field of vision that encourages the feeling of well-being inside the car.
Comfortable and luxurious seats The front seats ensure a comfortable posture thanks to their ergonomic design and their generous range of adjustment. At the rear, the absence of a tunnel creates more space for passengers, while the seats themselves provide excellent support. The rear bench seat, split 2/3 1/3, can be folded to suit space requirements without having to remove the head restraints.
A remarkable degree of user-friendliness
Practical storage spaces Everything that can potentially enhance comfort and practicality has been meticulously designed.The ingenious storage spaces located around the passenger compartment can be used by all occupants; the air-conditioned glovebox, which can hold a 1.5 litre water bottle, is accompanied by large door pockets and a cup holder, but also small sealed or open spaces for use as storage.
The wide central rear armrest available on many versions also has a folding storage space and cup holders. When folded, it conceals the flap that allows long objects to be carried in the boot. The boot, with a capacity of 407 dm3, comprises a large luggage area with two self-contained storage spaces to the side.
Its generous width of 1 100 mm is made possible by the multiarm rear suspension with dampers that are inclined rearwards.Two large suitcases can comfortably be placed side by side or one on top of the other.
Perceptible acoustic insulation. The excellent natural noise insulation of the 407 enhances the comfort of occupants thanks to the easiness with which front and rear passengers can converse. Laminated side windows, available as an option, give the interior a surprising sensation of calm and comfort.
Comfort features which can be shared Although the driver has a special “status” inside the 407, the vehicle pampers its passengers too. For example, they have access at the front to “instrument panels” for air conditioning, radio, telephone and GPS navigation, while the information displayed on the common monochrome or colour screen is visible to all occupants.
The 407 also boasts features that enhance the comfort of all its occupants. For example, the “follow me home” function keeps the headlamps on after the ignition has been switched off, to light up a path or an entrance door .
Air conditioning par excellence.
A safety feature for the driver and a source of comfort for all passengers, a vehicle’s air conditioning has become indispensable.However, air conditioning systems can have a number of drawbacks during use that are sometimes mentioned by users, such as increased fuel consumption or perceived air flow that is welcome to some but irritating to others.
However, the air conditioning with automatic regulation that is fitted to all 407’s comes with innovations that are designed to improve efficiency and meet the expectations of users in terms of comfort:
- A “gentle diffusion” system expels air unnoticeably via a new grille located at the top of the instrument panel and
distributes the remaining air flow through front-mounted vents and special rear passenger vents.
- A humidity sensor detects the onset of condensation in the passenger compartment and instructs the air conditioning
system to adjust accordingly.
- An “externally controlled” compressor significantly reduces the vehicle’s average fuel consumption.
- A pollen filter, combined with a layer of active carbon, further insulates the passenger compartment from external pollutants.
The 407’s air conditioning system is available in two versions, one offering single zone distribution, the other dual-zone distribution (with reference temperature and separate right/left distribution).
All information concerning the air conditioning is visible on the multifunction screen at the top of the instrument panel. Finally, rear lateral sun visors incorporated in the door cappings combine with a rear window blind to reduce the effects of excessive sunlight.
Particular attention has been paid to the driver and his or her environment, to make driving as easy and as safe as possible, but also a pleasure.
The driver’s seat for example, like the passenger’s, has a long cushion and a generous adjustment range – 240 mm for length, 50 mm for height, with tilt and lumbar adjustment by means of separate levers.The “more upright” steering wheel is also adjustable for rake and depth for up to 40 mm (in each axis).
It is therefore easy for individuals with a larger build to adopt a comfortable driving position. For ultimate comfort, memorisation of all settings – steering column, seats, door mirrors – is available on certain versions, with remote-control recall of stored settings.
Driving information is displayed on the instrument panel located within the driver’s field of vision.The instrument panel contains four or five steel-rimmed dials with either a display unit or a dot matrix for alarms and odometers.
The 407 is equipped as standard with an RD4 mono CD 4x15 W radio with six speakers. Featuring a bi-tuner and two antenna with a “diversity” system, it occupies a volume of 1.5 ISO for enhanced ergonomics and visibility. Its two aerials, integral in the rear window glass, are invisible.
In addition to duplicated controls on the steering wheel for enhanced safety and comfort, the car radio has numerous additional functions, in particular two analogue inputs, allowing the connection of an MP3 player for example.
Telematics equipment (RT3) is available as an option and includes audio, GSM telephone and GPS navigation functions. It is compatible with the TMC function, providing details of traffic conditions along the programmed route, which will be available shortly.
Emergency and local assistance telematics services are available on a contract basis, and in the event of air bag deployment, emergency services are called automatically via Inter Mutuelle Assistance, which can identify the vehicle’s location by means of the GPS. The device has two buttons:
one with a lion emblem enabling the user to get in touch with the Peugeot CCC;
the other – red SOS – to place a call with the emergency services.
A JBL hi-fi system can be combined with either of the car radio options.With an output of 240 Watts, it includes ten speakers in eight locations and a bass box located in the right-hand side storage compartment of the boot.
To complement these facilities, a new CD auto changer, compatible with the CDR and CDRW, is available.This, too, is located in the right-hand storage space of the boot.
All information concerning these communication systems appears either on the monochrome screen, with GPS information displayed in the form of pictograms, or on a 7" 16/9e colour screen with cartography.
The interior of the 407 is available in three styles –
– each designed to meet the expectations and requirements of potential customers: Comfort: on the basic level 407, this contemporary and bright style uses “lion grey” design. Sport: expresses dynamism and performance and is synonymous with driving pleasure. It uses “chrome triangle” design.
Four engines will be offered on the 407 saloon at the time of its launch: three petrol engines (two 4-cylinder models, 2.0 litre and 2.2 litre respectively, plus a 3.0 litre, 6-cylinder version) and one 2.0 litre HDi Diesel engine, equipped with a particulate emission filter (PEF). Since the EW7J4 petrol and DV6TED4 Diesel engines are currently undergoing homologation on the 407, their description and specifications will be published at a later date.
2.0 litre petrol EW10 J4 This is a 4-cylinder engine with twin overhead camshafts and 16 valves, with a displacement of 1 997 cm3 (bore 85 mm, stroke 88 mm). It develops a maximum power of 100 kW at 6 000 rpm and a maximum torque of 190 Nm at 4 100 rpm. With a torque of 170 Nm from an engine speed of 1 800 rpm, it gives the vehicle excellent flexibility at low engine speeds.
Comprising a compact light-alloy engine block, it incorporates cast-iron cylinder liners inserted at the foundry and a cylinder head with twin overhead camshafts driven by a toothed belt directly operating the timing gear of each camshaft.The intake incorporates a motorised throttle housing, which, controlled electrically by the ECU, enhances driving comfort while at the same time reducing emissions. It also authorises dialogue between the engine and the electronic stability programme (ESP).
Management electronics comprise a Magneti Marelli 48 P sequential injection and a SAGEM BBC 2.2 twin-static ignition.
2.2 litre petrol EW12 J4 With a capacity of 2 230 cm3 (bore 86 mm, stroke 96 mm), this engine develops a maximum power of 116 kW at 5 650 rpm and a maximum torque of 217 Nm at 3 900 rpm. From an engine speed of 2 000 rpm, it provides a torque of 200 Nm, representing 92% of the maximum available torque up to an engine speed of 5 500 rpm.This characteristic enhances the car’s acceleration, without having to “overwork” the gearbox. In addition, to reduce the natural vibrations transmitted by a 4-cylinder engine during acceleration, two balance shafts driven by the crankshaft are featured on this engine.
This light-alloy engine (engine block) has four valves per cylinder and twin overhead camshafts. To provide good torque at low engine speeds, the intake camshaft is equipped with a variable timing system (on/off,VTC), offset by 20° with respect to the crankshaft. Engine management is ensured by a Magneti Marelli 4MP unit, which controls a motorised throttle housing, phased sequential injection and sequential ignition with one coil per cylinder.
3.0 litre petrol ES9A This V6 model featuring 6 cylinders at an angle of 60° has a capacity of 2 946 cm3, thanks to a bore of 87 mm and a stroke of 82.6 mm, and develops a maximum power of 155 kW at 6 000 rpm and a maximum torque of 290 Nm at 3 750 rpm.
Derived from the ES9J4S engine that is fitted to 406 and 607 models, it has a similar technical specification but benefits from a 2% gain in power (+ 3 kW) and torque (+ 5 Nm).
These improvements in performance are due in part to the adoption of a variable timing system (VVT) on the intake camshafts, with an angular variation of between 0° and 40° with respect to the crankshaft timing.This is carried out one degree at a time, thereby allowing optimum filling of the combustion chambers regardless of engine speed.
This characteristic makes the engine both flexible and powerful. The other reason for this engine’s improved performance is a new exhaust system fitted with a dual-mode active silencer.
By controlling the feed of gases into the silencer according to driving conditions, this system improves acoustic properties in normal conditions of use and increases performance under load.
The engine block and cylinder heads with four valves per cylinder are manufactured from light alloy and form a particularly rigid assembly. Engine management is by means of a Bosch ME 7.6 unit controlling phased sequential injection and ignition composed of six “pencil” coils.
The Diesel engine
2.0 litre Diesel HDi DW10 BTED4 – PEF This 4-cylinder engine is a new generation of the DW10 ATED 79 kW engine that first appeared in 1998.The top section of this new 16-valve version has been particularly revised to achieve a major breakthrough in terms of driving comfort, fuel consumption and emissions control.
This new engine is equipped with a second-generation particulate emission filter (PEF) and complies with EURO 4 standards.The PEF is designed to retain particles and then burn them by means of an innovative and exclusive “Common rail” process combined with the Eolys additive.
This filter adapts in use to particular driving styles and traffic conditions, determines the mileage and even the best moment to regenerate.This operation occurs without the driver being aware of it.
The filter is replaced during the 120 000 km service, when the additive reservoir is refilled. In the event of malfunction, a warning light on the instrument panel informs the driver accordingly. With a capacity of 1997 cm3 (bore 85 mm, stroke 88 mm), this engine features a Garrett variable geometry turbocharger with a vacuum-controlled turbo regulation valve and is also fitted with a front-mounted air/air intercooler. It develops a maximum power of 100 kW at 4 000 rpm, and a maximum torque of 320 Nm at 2 000 rpm. In the four top gears, it can attain 340 Nm at 2 000 rpm thanks to the “over boost” function, which comes into play with the engine under full load at between 1 500 rpm and 3 200 rpm.The maximum torque is thus temporarily increased by 36% compared to the DW10 ATED.
The 407 is fitted with engines that can be combined with either a manual 5-speed (BE4/5) or 6-speed (ML6C) gearbox, or with an electronic 4-speed (AL4 – 4HP20) or 6-speed (AM6) automatic autoadaptive gearbox.
The ML6C manual gearboxes that equip the 407 are adapted to characteristics specific to each engine.These differences concern gear and axle ratios, which are shorter with the petrol engine than with the Diesel engine.
The automatic gearboxes feature a “Porsche Tiptronic System” sequential control and are mounted transversely at the end of each engine. The 6-cylinder petrol engine (ES9A) with a power of 155 kW and a torque of 290 Nm is coupled uniquely with a new AM6 6-speed automatic gearbox. Developed by Aisin A.W.(*) in accordance with specifications issued by the PSA Peugeot Citroën group, this gearbox is genuinely innovative, allowing for the first time in the world a 6-speed transmission, combined with a high-torque transverse mounted engine.Its torque capacity, which extends to 450 Nm, makes it compatible with the group’s future engines . Schematically, its underlying principle is to use the gear ratio combinations of two epicyclic gear trains, one single, the other double.The assembly is controlled by just five friction clutches managed by a compact integral computer.
This principle allows a compactness and weight hitherto unheard of for a 6-speed gearbox, on a par with those of 4-speed automatic gearboxes and better than those of automatic 5-speed transverse gearboxes with a similar torque capacity.
The weight of the AM6 does not exceed 93 kg and is therefore comparable (90 kg) to that of a 4-speed automatic gearbox such as the one equipping the V6 406 for example. The short first gear gives the car verve when starting off and the six gears exploit the engine’s full potential, with a slight drop in engine speed accompanying each gear change. The car’s dynamic performance is therefore significantly enhanced compared to the previous performance of the 406 V6 automatic gearbox.
Furthermore, the functions of the AM6 are the same as those of the 4HP20, with the addition of the possibility of locking the converter(*) in all gears, which benefits fuel consumption. Moreover, the “extended” sixth gear reduces both fuel consumption and noise levels. On the 407 V6, the resulting performance is improved compared to that of the 406 V6, both in terms of fuel consumption and acceleration.
With the ability to recognise the driving style naturally adopted by the driver, as well as the road surface, special attention was given to the quality and speed of automatic gear changes. Driving pleasure is also enhanced by two possible control modes: one automatic and autoadaptive, for peaceful and stress-free driving, the other more active, thanks to the “Porsche Tiptronic System” sequential control.
A reminder of which gear is engaged and of the selected programme (normal, sport or snow) is shown by the multifunction display on the instrument panel. For added safety, the gearbox has a “shift lock” function that prevents release of the Park position (P) while the engine is running unless the brake pedal is depressed at the same time.
Similarly, a buzzer is activated when the driver opens his door after switching off the engine without having returned the gear lever to the Park position.
When Peugeot’s engineers set out to design the wheels and suspension for the new 407, they looked for an optimal solution that would ensure the very best ride and handling characteristics to satisfy the most demanding of customers .
The expertise of our engineers in this field therefore allowed them to conceive, design and develop solutions that provided a satisfactory response to customers’ legitimate expectations, in terms of road holding, dynamic safety, driving pleasure and comfort in general.
Based on a floor pan exhibiting a high torsional rigidity, the choice fell naturally therefore on a high-tech design that encompasses a generous use of lightweight materials on a double wishbone front axle, and an integral multi-arm rear suspension with the damper and springs inclined rearwards.
At the front, the double wishbone drop link design, in part derived from competition cars allows the separation of vertical suspension travel and deflection.With this new axle, the wheels turn about an axis formed by two ball joints located between the hub carrier and a hub carrier support (or strengthening strut).Vertical movement is managed by three flexible joints situated between the hub carrier support and the two wishbones.
This design ensures a small hub carrier angle with relatively little wheel axis offset (caster) and preserves optimum body control characteristics. In terms of performance, this results in very positive directional control under all circumstances, on both rough and deeply rutted roads. In addition, it virtually eliminates steering adjustments, giving outstanding, precise feel when cornering, it reduces sensitivity to wheel imbalance and adds suppleness to the suspension.
Compared to the first-generation multi-arm rear suspension that made its appearance on the 406, the all-new rear suspension of the 407 differs essentially by the inclusion of an inclined spring and damper assembly and of a longitudinal arm and linked to the hub carrier to ensure longitudinal control.
The entire suspension is assembled on a light-alloy crossmember with mechanical characteristics that not only give the suspension static geometrical precision, but also ensure rigorous dynamic positioning of each wheel, guaranteeing excellent steering and ensuring that the car remains balanced under all circumstances.
Most constituent parts of the axles are manufactured from light alloy, with the more complex of them using Cobapress aluminium.
The front axle
Under the engine compartment of the 407 there is a long light-alloy sub-frame formed by two distinct sections. The front section of the sub-frame consisting of welded aluminium sections is rigidly attached to the rear crossmember.
Weighing less than 6 kg, it essentially performs three passive safety functions, namely: support of an impact beam to “contact” the legs of pedestrians; repairability, thanks to a pre-deformed absorption zone; and, in the event of high-speed impact, absorption of energy through a programmed deformation.
The rear section, consisting of a cast aluminium crossmember, is dedicated to the suspension and is very strong, being joined to the structure by means of vibration absorbing mountings.
It weighs only 15 kg, i.e. 8 kg less than any welded-steel equivalent. This section, unique regardless of engine, is located so as to absorb braking forces transmitted by the front movement of the wishbone.
Each suspension unit has a cast-iron hub carrier connected to a steering rod.Two ball joints with a tapered fit connect it to the hub carrier support and are thus able to accommodate different types of deformation between the cast iron (hub carrier) and the aluminium (hub carrier support).
The welded assembly of the aluminium hub carrier support is an impressive part and plays an important role, since it supports both hub carrier ball joints, as well as that of the anti-roll bar rod, those of the spring and damper and the double suspension wishbones.This multi-function hub carrier fits around the drive shaft and weighs only 4.250 kg.
When driving, wheel geometry, is also maintained by the double wishbone configuration. On the sub-frame side, the lower wishbone, manufactured from forged steel, has two flexible mountings of differing hardnesses. It operates in conjunction with rubber/polyurethane composite links of varying rigidity: axial (braking forces for the front movement) and radial (steering for the rear).
The upper wishbone, manufactured from high-strength steel plate, supports four traditional flexible mountings, two on the hub carrier and two on the upper strut mounting rigidly attached to the structure. Its main function is to control the direction of the wheels.
The upper bearing support manufactured from Cobapress aluminium provides the interface with the body shell and accommodates the upper mounting of the spring and damper assembly. The front axle naturally incorporates a Ø 23.5 to 25 mm anti-roll bar. Mounted on two bearings rigidly attached to the sub-frame crossmember, each of its ends is connected to the hub carrier support by means of a link with two ball joints.
This construction greatly enhances the efficiency of the anti-roll bar by ensuring accurate and fast mechanical transmission of the slightest movement of the body during cornering.
The rear suspension
The multi-arm rear suspension is supported by an aluminium crossmember. It consists of two cast-iron sections connected by a profiled tube, to which they are welded.The assembled crossmember weighs 14 kg and is joined to the structure by means of four flexible mountings with inbuilt radial stiffness and axial flexibility.This extremely rigid crossmember provides the interface with each suspension unit. Each one has an upper wishbone, two lower transverse arms, one longitudinal arm, a hub carrier, a spring and damper assembly and a solid anti-roll bar (Ø 19 and 19.8 mm) that connects the suspension units.
The anti-roll bar is maintained by two bearings rigidly attached to the rear floor. It is connected to each hub carrier by means of a link with two ball joints and plays an important role in load transfers in transferring loads during cornering.
The hub carrier, manufactured from Cobapress aluminium, has a ribbed design and is specially strengthened to resist operatin stresses. It is unaffected by the forces and torques transmitted via the wheel, in particular braking torque, which it simply transmits to the different suspension arms.
The upper wishbone, also manufactured from Cobapress aluminium, operates vertically and has two traditional flexible joints rigidly attached to the crossmember.The third, connected to the hub carrier, is special, since it has a high radial stiffness (corresponding to the wheel axis) and axial flexibility to “gently” absorb peak longitudinal forces. The upper surface of the wishbone makes contact with a bump stop located on the structure. In its lower section, the suspension unit has two transverse arms manufactured from pressed steel that connect the hub carrier to the crossmember.The rear arm contributes to the lateral integrity of the hub carrier and absorbs dynamic vertical stresses.The adjustable front arm, or track control arm, absorbs transverse stresses and at the same time controls tracking. Its static adjustment is finalised during assembly of the suspension on the crossmember.
Still in the lower section, each suspension unit has a third, forward-facing arm.This provides the link between the hub carrier and the underframe and absorbs longitudinal forces. Manufactured from Cobapress aluminium, it filters impacts and helps to control axle geometry and movement as it exhibits radial flexibility and axial rigidity.
Lastly, there is a spring and damper assembly, inclined rearwards and connected between the crossmember and the hub carrier. Since the purpose of the 407’s rear suspension is to preserve the comfort of its occupants, it also ensures dynamic steering of the car thanks to rigorous control of wheel geometry in all circumstances.
Upholding the Peugeot tradition and following the example of its predecessors, the 407 is equipped with dampers, developed ‘in-house’, at the front and rear. Surrounded by springs, these spring and damper assemblies, through their design and their positioning, guarantee efficient support for the body as well as a high level of filtering to ensure optimum road holding and dynamic comfort. On each suspension unit, the naturally varying flexibility of a bump stop helps to optimise vehicle stability whilst preserving vertical comfort.
The gas pressure dampers incorporate multi-valve technology (four valves per damper) and their shock absorption characteristics correspond to the weight distribution of each version, as well as to the flexibility of the corresponding springs.
With the 6-cylinder engine, shock absorption is variable according to nine distinct settings, and contrary to previous solutions that operated on the basis of individual axles, on the 407 each of the four dampers is controlled separately thanks to the presence of a movement sensor rigidly attached to each wheel.
This new design allows adaptive performance on driver behaviour, as well as the forces transmitted by the road.
This makes it possible, for example in a straight line and at a constant speed, to enhance comfort on bumpy roads in terms of bounce, pitch and roll. Additionally, since automatic stiffening takes account of the mass applied to each wheel, it guarantees road holding in bends, and during low- and high-speed braking and acceleration.A push-button allows optional reinforcement of variable damping for greater firmness, to give the car an even more dynamic feel.
Recognised for its precision and the accuracy of the information it provides, rack and pinion steering has been retained for the 407.To achieve the best possible power steering / engine combination, in conjunction with tyre dimensions and according to the specific model, three different power steering systems have been developed for the car.The steering guarantees both driving precision and weight that adapts to all possible situations.
The power steering on entry level cars equipped with the EW7 J4 and DV6 BTED4 engines features a variable capacity pump driven by the engine. It provides maximum assistance at low engine speeds (parking manoeuvres) and diminishes as soon as the engine reaches a speed of around 2 000 rpm or 3 000 rpm – depending on the precise engine.
With the 2.0 litre and 2.2 litre petrol and Diesel engines, the electro-hydraulic power steering is supplied by an electropump unit controlled according to the speed of the car and the speed of rotation of the steering wheel. In addition to a natural tendency to reduce fuel consumption and therefore CO2 emissions, this system significantly increases driving comfort.
Finally, the 6-cylinder 407 is equipped with variable hydraulic power steering.With this system, power steering is supplied by a computer-controlled valve that takes into account a multitude of data, such as vehicle speed, engine speed, turning angle and steering wheel rotational speed.This device further enhances performance by offering improved response and comfort in all circumstances. Driving aids and alarms to help driver concentration To assist with parking manoeuvres, the rear-view mirrors can be linked to reverse gear, while parking sensors evaluate distances.
Similarly, to assist the driver in adhering to self-imposed speed limits, a variable cruise control (RVV) is available, which can be coupled with a variable speed limiter (LVV) with a slightly delayed application.
Also available is a system for the direct detection of low tyre pressure or punctures, with identification of the faulty wheel and an alarm message on the multifunction screen.
On the 407, braking is optimised to each car’s weight and level of performance. Common features include two separate ‘X’ circuits, braking assistance, and four generously proportioned discs, two of which are ventilated at the front.
All cars also feature an anti-lock braking system (ABS) with integral braking control on individual wheels, including distribution between the front and rear axles (electronic brake force distribution) and a new system allowing independent control of the RH and LH wheels. In addition, the 407 is fitted with emergency braking assistance and automatic activation of the hazard warning lights in the event of sharp deceleration, which operates independently of the ABS.
While ABS prevents a wheel from locking during emergency braking and therefore preserves the ability to steer the car, control of individual wheels guarantees optimum braking efficiency and stability of the car during braking, particularly in bends without ABS regulation or dynamic stability control.
Emergency braking assistance provides maximum braking power according to the speed at which the brake pedal is depressed. Automatic activation of the hazard warning lights during sharp deceleration informs following vehicles of an abnormal situation, leaving the driver free to concentrate on controlling the vehicle.
For the 407, engineers have included a latest generation ESP(*) compatible with systems controlled and installed on all versions, such as individual wheel braking and ABS. To utilise the high potential of the wheels and suspension of the new car, the latter has been developed with and without ESP in order to offer a high level of active safety whilst preserving genuine driving pleasure.
The ESP developed in partnership with TWR includes an ABS system, an anti-skid function (ASR) acting on engine management and the brakes, and an emergency braking system, all combined with integral control of braking on individual wheels to ensure the best possible efficiency and optimum stability of the car.
The ESP also incorporates the “Stability Control” ECU, which, thanks to a steering wheel sensor and a yaw sensor, can detect any tendency to under- or over-steer. As a result of detection, the computer orders a correction to be carried out to ensure, as far as the laws of physics allow, that the car follows the direction requested by the driver.
Two software programs incorporated in the computer have been designed and developed specially for the 407. For correction of under-steer and to return the car to its intended direction as quickly as possible, the correction is carried out on the two front wheels and on the inside rear wheel.
For over-steer, the correction involves two distinct operations.Firstly, it takes the form of a preliminary command issuing an initial level of regulation that stabilises the vehicle in a manner transparent to the driver.This preliminary command “reduces” the system’s response time in the event of the need for more strenuous intervention.
Secondly, the software logic adapts itself to the driver’s driving style and to emergency situations. Because the stability control is able to detect, for example, sporty driving and high-speed evasive manoeuvres, its regulation in the first case is slightly delayed in order to improve the car’s agility.This system prevents unnecessary intervention and ensures the outstanding dynamic character of the 407.
The specification of the wheels and suspension of the 407 provide dynamic qualities that offer excellent passive safety.
The innovative structure (see section entitled Architecture – Structure) and the means of restraint present in the passenger compartment, together form an outsanding protective shield that makes the risk of injury more unlikely in the event of impact. At the same time the design ensures maximum comfort for the occupants. Inside this “protective cage”, occupants benefit from a highperformance restraint system.
The front seats The driver is protected in the event of impact by a twin generator, dual volume front air bag, the pressure and volume of which when deployed depend on the severity of the impact and the driver’s weight. After deployment, the volume of the bag may vary between 42 litres and 83 litres.
The driver can also count on a steering column that collapses by 80 mm and a steering column air bag with a capacity of 20 litres that significantly enhances protection of the knees and shins in the event of collision, by limiting their impact against certain rigid parts of the vehicle.
In the outer part of the seat, a side air bag with a capacity of 10 litres protects the chest and abdomen in the event of side impact, while the driver also shares the head protection afforded to the rear passenger by the 23-litre curtain air bag.
The front passenger similarly benefits from a twin generator, single volume front air bag with a capacity of 120 litres, adapted to the severity of the impact. Operation of the air bag can be turned off by means of a deactivate switch, using the ignition key - if a child seat is installed in the front - while a warning light on the instrument panel indicates whether its status is enabled or disabled. The front passenger, like the driver, is protected against side impact by a 10-litre side air bag for the chest and abdomen, and by the 23-litre curtain air bag shared with the rear passenger, affording protection to the head.
The means employed to ensure the safety of occupants, both large and small, create a genuine sense of well-being in the 407. To withstand impact, the long aluminium sub-frame dissipates energy and distributes force two ways – upwards and downwards – while engine movement is controlled by an "impactor" and the steering column collapses by 80 mm.
Occupants also benefit from high-performance restraint systems. Front passengers have active “anti-whiplash” head restraints, adaptive front air bags coupled with pretensioning seat belts and a force limiter, plus a ‘fasten seat belt’ indicator, as well as side air bags in the sides of the seats and curtain air bags that are shared with the rear passengers.
The driver benefits in addition from an item of safety equipment that is not widely available, namely a steering column air bag to protect the lower limbs.
Rear passengers will benefit from seat belts fitted with a ‘fasten seat belt’ alarm. As an option they can also choose rear side air bags coupled with pretensioning seat belts. Small children can have their car seat installed in all four passenger seats and their Isofix seat in the rear outer seats.
To give all occupants an added sense of security, the doors and boot lock automatically from a speed of 10 km/h (6 mph). This operation is programmable by the user.
An anti-intrusion alarm combined with a deadlocking function is also available as an option. Thus protected, occupants of the 407 can relax and enjoy the benefits of the car’s on-board communication technology.
Both driver and front passenger have the benefit of pretensioning seat belts and a force limiter rated at 450 DaN that work “in tandem” with the front air bag to guarantee optimum protection.
These seat belts are equipped with a double ‘fasten seat belt’ alarm, firstly by means of a visual indicator on the instrument panel, then in the form of a buzzer once the car reaches a speed of 15 km/h.The passenger seat is of course equipped with an occupant detection system.
In the event of rear impact, “active” seat backs prevent whiplash by keeping the head restraint in close contact with the occupant’s head, thereby avoiding hyper extension of the neck.
The rear seats Passengers in the rear outer seats have curtain air bags for head protection and three-point seat belts equipped with a force limiter rated at 600 DaN.These passengers can optionally benefit from a pack consisting of side air bags coupled with pretensioning seat belts.
These side air bags are located in the rear door panels and have an individual capacity of 9 litres. Like the side seat belts, the central seat belt has three anchorage points and also features a web lock.
To encourage rear passengers to wear their seat belts and also to provide a warning should a child become unattached, the number of fastened rear seat belts is counted and displayed clearly on the multifunction screen when the ignition is switched on. Any change in status is indicated jointly by a warning light on the instrument panel, an alarm message on the screen and a buzzer.
Small children … Each of the four passenger seats can accommodate a child seat, while both rear outer seats have special fittings for the installation and secure attachment of an Isofix seat.
Windscreen wipers play an important role in visibility.The 407 is equipped with new powerful single-blade butterfly arms, each with its own motor. Extra-flat, they remain very discreet and follow every contour of the distinctively curved windscreen. Most versions have an automatic rain sensor function, coupled with automatic activation of the headlamps.
The driver can opt for an anti-glare rear-view mirror that uses electrochrome technology to make night-time vision more comfortable, while automatic headlamp activation improves the comfort and safety of occupants and other road users.