Mercedes-Benz ML500 (2006)

The pronounced edges of the muscular wings grow powerfully from the bodyshell, indicating not only power but also precision and sure-footedness, while effectively emphasising the large wheels. Depending on the equipment line, the new M-Class is fitted with 17 to 19-inch light-alloy wheels whose unbroken surfaces and stabilising chamfers suggest solidity and sportiness to underline the four-wheel drive character of the Mercedes-Benz M-Class.

Rear end: pronounced contours

The rear end is substantially characterised by the extended, curved rear window, which combines with the third side windows to form a wide, panoramic surface and acts together with horizontal edges to suggest powerful forward motion while visually emphasising the vehicle's width while reducing its height. This is reinforced by the tailgate with its high-quality chrome handle and by the high rear bumper, which has a colour contrast like its front equivalent and likewise confirms the off-road character of the M-Class with its excavator bucket design and underride guard.

Especially when viewed from the rear, the wide track and pronounced wheel arches make an extremely sporty impression and lend stability to the vehicle's appearance. A third brake light integrated into the prominent rear spoiler rounds the rear end off at the top and provides another highlight.

Interior: comfort with elegance and attention to detail

The interior of the new M-Class is characterised by self-assured elegance with calm, unbroken surfaces, meeting the requirements of demanding customers who expect an SUV to accompany them with serenity, absolute reliability, comfort and charm in any situation in life. The unique atmosphere inside the new M-Class is also heightened by interestingly contoured features and high-quality materials which are finished with craftsman-like precision and attention to detail.

Drivers of the new M-Class are seated at a new four-spoke multifunction steering wheel whose two lower spokes feature an appealing aluminium finish. Behind it there is a broad instrument panel which is horizontally divided into an upper and lower section in both form and colour. Circular ventilation vents are arranged in the centre and at the left and right extremities; their chrome surrounds are reminiscent of the engine pods on an aircraft wing. The upper section of the instrument panel arches powerfully over the instrument cluster, which has two slanted tubular binnacles for good legibility and a sporty look. A touch of elegance is provided by their fine chrome surrounds.

The calm, clearly arranged centre console features easily accessible and thoughtfully positioned, ergonomic controls and displays. Various infotainment systems are also located here - from a CD radio to a CD radio with integral navigation or the latest COMAND system with DVD navigation and a large colour screen (optional).

The centre console extends into the prominent tunnel cladding with its stowage compartments and integral cupholders. This also features two robust, horizontal grab handles which not only echo the principal lines of the overall design, but also provide a firm hold when driving off-road.

The two-tone colour scheme of the interior along the horizontal dividing line is also continued in the centre console, tunnel cladding and door panels. These panels are concave in shape at elbow level, thereby increasing elbow room and adding a stylish feature to the interior with their pronounced contours.

Depending on the chosen appointments, the centre console and doors feature wood, wood/chrome or aluminium trim. As on the exterior, the trim strips in the door panels are slanted forwards to echo the dynamic lines.

The interior of the new M-Class is characterised by perfectly finished, high-quality materials which are pleasant to the touch, e.g. the soft leather of the armrests and sophisticated decorative seams. The result is a consistently luxurious interior design. Three interior colours - black, alpaca grey and cashmere beige - are available for the new M-Class. These can be combined with two non-metallic and nine metallic paint finishes.

Refined power

The trendsetter among modern off-roaders has stepped up another gear: Mercedes-Benz presents the new M-Class. With state-of-the-art technology such as three powerful new engines, the standard-fitted seven-speed automatic transmission 7G-TRONIC, the now even more effective four-wheel drive system 4-ETS, AIRMATIC air suspension and the anticipatory occupant protection system PRE-SAFE®, the M-Class is set to reaffirm the off-roader's leading position in a fast-growing market segment which Mercedes-Benz created with the preceding model in 1997. After its premiere at the 2005 Detroit Auto Show, the new M-Class will be introduced onto the US market in the spring of 2006 and in Europe in the summer.

You need look no further than the design of the new Mercedes-Benz M-Class, with its beguiling blend of heavily contoured surfaces and taut lines, to admire the majestic character of the second-generation off-roader. The swept-back windscreen, striking front wings and rising shoulderline of the new car set the unashamedly sporting tone, a theme developed by the proportions of the body: the new M-Class is 150 mm longer (now 4780 mm), 71 mm wider (now 1911 mm) and 5 mm lower (now 1815 mm with roof rails) than its predecessor. The wheelbase has grown by 95 mm to 2915 mm.

Three of the four engines available for the 2005 model are new and outstrip the output and torque of the power units for the outgoing model to the tune of up to 38 per cent. Cutting-edge drive-system technology and impressive aerodynamics (the Cd value is down to 0.34 from the previous 0.40) combine to cut fuel consumption by as much as ten per cent.

A new V6 diesel engine, available with two different outputs, is celebrating its premiere. It features third-generation common-rail direct injection and the latest in piezo injectors. The unit in the ML 320 CDI delivers 165 kW/224 hp and places a maximum torque of 510 Newton metres on tap from 1600 rpm. Also on hand to offer the twin benefits of six-cylinder comfort and dynamism is the new ML 280 CDI, serving up 140 kW/190 hp and a peak torque of 440 Newton metres. The diesel models burn just 9.4 litres of fuel per 100 kilometres (NEDC combined), making the new M-Class one of the most economical off-roaders in its class. Another new arrival is the V6 petrol unit powering the ML 350, with 200 kW/ 272 hp and a maximum torque of 350 Newton metres. The engine range is headed by the eight-cylinder in the ML 500, which now has an output of 225 kW/306 hp.

The globally unique seven-speed automatic transmission 7G-TRONIC is fitted as standard in all variants of the new M-Class. Intelligent shift management allows the transmission to make optimum use of the engine's enviable reserves of power, while making a major contribution to fuel economy. 7G-TRONIC can now be operated electronically using a selector lever positioned close to the steering wheel, a new technology which Mercedes-Benz has christened DIRECT SELECT. Additional steering-wheel gearshift paddles enable the driver to glide manually through the seven gears.

Ready for rough terrain: the off-road package with AIRMATIC

Mercedes-Benz has taken the permanent four-wheel drive and 4ETS traction systems to the next level by incorporating additional functions such as a Downhill Speed Regulation, Start-Off Assist and the off-road ABS system. The M-Class can be ordered with two different variants of the four-wheel drive system, allowing it to meet the varying requirements of off-road drivers: in addition to the basic version, a new off-road package is optionally available which enables the M-Class to master even the toughest routes across rough terrain. Its primary features include a two-speed transfer case with an off-road ratio, manually or automatically selectable differential locks (100 per cent) between the front and rear axle and on the rear axle, and a modified version of the AIRMATIC air suspension system tailored to off-road driving, which raises the ground clearance by 110 mm to as much as 291 millimetres and the vehicle's fording depth to a maximum of 600 millimetres.

The air suspension also significantly improves ride comfort, which is why Mercedes-Benz offers a roadgoing version of this technology as an option. AIRMATIC teams up as standard with the Adaptive Damping System (ADS), which adjusts shock absorber response to suit the current driving situation. All this accelerates the M-Class into a new dimension in driving dynamics and ride comfort.

Mercedes engineers have also redeveloped the front and rear suspension of the M-Class: the double-wishbone front suspension makes a significant contribution to reduced road roar and tyre vibration, ensuring impressive driving dynamics with its raised aluminium wishbones. The new rear axle has a four-link suspension system.Standard-fitted light-alloy wheels and wide 235/65 R 17 (V6 models) or 255/55 R 18 (V8 model) tyres emphasise the sporting pedigree of the new M-Class.

A new era in safety: PRE-SAFE® makes its debut in this vehicle class

The Mercedes-Benz M-Class also sets the pace for other off-roaders in terms of safety. Its occupant protection system is underpinned by a self-supporting body structure with large deformation zones in the front and rear ends, and a wealth of state-of-the-art technology from the luxury class as standard. This includes adaptive, two-stage airbags for the driver and front passenger, front sidebags and windowbags, as well as belt tensioners and belt force limiters for all seats. In the event of a rear-end collision, the newly developed NECK-PRO crash-responsive head restraints (optional) provide additional protection for the driver and front passenger.

With the option of adding the anticipatory occupant protection system PRE-SAFE® to the mix, the new Mercedes off-roader raises the bar in its class. This multi-award-winning technology provides a reflex response to critical driving situations where an accident threatens to occur, preparing the car and its occupants for an impending collision. PRE-SAFE® acts in advance to tighten the driver and front passenger seat belts, bring the fore-and-aft setting and the cushion and backrest angle of the electrically adjustable front passenger seat (optional) into a more favourable position and close the sunroof (optional) if a rollover threatens.

It is by forming an unparalleled synergy of active and passive safety that PRE SAFE® can prepare the car and its occupants for a possible impact. The system is linked to the anti-lock braking system (ABS), Brake Assist and the Electronic Stability Program (ESP®), whose sensors identify dangerous driving manoeuvres. Mercedes-Benz also uses these data for anticipatory occupant protection.

The new M-Class also boasts exceptional long-term quality - another Mercedes hallmark. The fully galvanised body is given extra protection from corrosion by means of an organic coating at specific points. Structural areas subjected to high stresses are cavity-sealed, and folds are seam-sealed. Large plastic underbody panels eliminate the necessity for conventional PVC undersealing.

Part of the standard specification for the off-roader is a new type of paint finish developed on the back of nano-technology, which made its series-production debut in Mercedes-Benz vehicles. Offering significantly improved scratch resistance compared to conventional non-metallic or metallic paint finishes, nano-particle clearcoat provides a noticeably enhanced sheen.

Like all Mercedes passenger cars, the M-Class also comes with the 30-year MobiloLife mobility and value-retention warranty.

At the level of the luxury class: greater comfort and more space

The interior of the new M-Class also exhibits typical Mercedes quality, thanks to higher-quality materials, more pleasant touch and feel characteristics and significantly improved spaciousness for all the vehicle's passengers. For example, at 880 mm, the distance between the front and rear seats is 15 mm greater than that in the outgoing model, achieving a level more familiar in a luxury-class saloon. Knee-room for the rear passengers has been increased by 35 mm and elbow width by 32 mm.

M-Class customers can select the seats for their new off-roader to suit their personal comfort requirements. In addition to the standard-fitted front seats with electrically adjustable height, backrest and cushion angle, sports seats with special backrest contours can also be specified.

Up to 2050 litres of load capacity offers ample space for luggage and sports equipment

The cushions and backrests of the rear seats are split 60:40 and can be folded down. Removable cushions can be ordered as an option, creating a level loading surface stretching 2.10 metres in length through the rear of the car. The maximum load capacity is 2050 litres (VDA measuring method), significantly more than comparable competitors.

The proven EASY-PACK system makes the boot area of the M-Class easier to load and unload. Among other features, it can be optionally supplied with an electrically operated tailgate and a package designed to secure items safely in the load area.

State-of-the-art support systems familiar from the luxury-class Mercedes models help to relieve driver stress, enhance comfort and further improve safety. The M-Class is optionally available with the newly developed multi-zone THERMOTRONIC automatic climate control system, the PARKTRONIC parking aid and the control and display system COMAND APS with Europe-wide DVD navigation. Bi-xenon headlamps with the Active Light System and the cornering light function (optional) enhance driving safety during the hours of darkness.

A success story beginning in 1997: blazing a trail for modern SUVs

With its unique design concept, the Mercedes-Benz M-Class led the way for a new generation of off-roaders on its premiere in 1997, and a whole series of international prizes and awards have since underlined the qualities of the Mercedes-Benz M-Class in the fields of design, functionality, driving pleasure, safety and off-road performance.

A total of over 620,000 drivers around the world have so far opted for the original "Sports Utility Vehicle" (SUV), making it one of the most successful models in its class. And the arrival of the second-generation M-Class in spring 2005 is set to open a new chapter in this automotive success story.

Bodyshell and safety: Exemplary occupant protection and aerodynamics

The assignment to develop a modern off-roader with a future-oriented concept was taken very seriously by the bodyshell developers at the Mercedes-Benz Technology Center. Nothing remained sacred, and all the body parts and components were re-examined. Safety, lightweight construction, operating reliability, handling stability, aerodynamics and long-term durability were just some of the many aspects which had to be considered and reconciled, even though some requirements seem contradictory at first sight. However, resolving apparently conflicting aims made the M-Class project all the more interesting for the engineers in Sindelfingen, and encouraged them to redouble their efforts.

A self-supporting, rigid bodyshell creates the conditions for safe handling and a high level of ride comfort, and forms the basis for even better occupant protection and modern lightweight construction methods. This is where the new M-Class differs from the preceding series with its structural frame. In order to cope with the high loads occurring in off-road operations, the highly stressed areas between the vehicle suspension and the bodyshell were redesigned and - above all - redimensioned.

One indication of the bodyshell's qualities is the considerably higher torsional rigidity, which is now 2.18 millimetres per metre (static) and therefore significantly betters that of the preceding series. Accordingly the bodyshell makes an important contribution to the noticeably improved vibration comfort and excellent handling stability of the new M-Class. This outstanding torsional rigidity is in part due to a continuous frame structure in the roof area, which is used to attach the tailgate and also forms a robust connection between the side walls, floor and rear roof frame. This so-called "D-ring" literally has a firm grip on the entire bodyshell and increases its torsional rigidity.

The body of the M-Class has been generally redimensioned: the new off-roader is 150 millimetres longer, 71 millimetres wider and five millimetres lower than its predecessor. The increased length is mainly due to the 95-millimetre longer wheelbase and the 56-millimetre longer rear overhang.

Two thirds of all body panels made from high-strength steel alloys

The latest production processes and the intelligent use of materials have made progress possible with respect to lightweight construction, tolerances and ease of repair. While conventional steel continues to predominate in the material mix for the new M-Class, Mercedes-Benz has made a five-fold increase in the proportion of high-strength alloys, which offer maximum strength for the minimum panel thickness and weight. In terms of total body weight, 62 per cent of all the body panels are now of high-strength steel alloys. Some of these, e.g. those of dual-phase steel, are even in the "very high strength" category. The special, two-phase microstructure of this alloy is capable of withstanding very high loads and therefore contributes significantly to the exemplary stability of the front end and passenger cell.

Numerous sheet metal components in the bodyshell of the new M-Class are assembled according to the "stress-relieved joining" principle, which allows a high level of precision. For example, the flanges at the edges of steel panels are designed in such a way that any tolerances are already compensated when positioning the sheets together, which permits body components to be welded together without significant stresses. This joining technique and the precise design of the body components also makes a major contribution to corrosion protection, as it substantially dispenses with additional brazed connections and MAG-welding seams which are generally seen as areas particularly vulnerable to corrosion.

Fully galvanised body panels and more scratch-resistant paint based on nano-technology

As in all the latest Mercedes passenger cars, the long-term corrosion protection of the new M-Class is based on fully galvanised sheet metal which is also organically coated on both sides, depending on the area of application. This coating also contains rust-preventing zinc pigments. Highly stressed structural areas of the bodyshell are also protected by cavity preservation, and the welding seams are carefully sealed. The six-section plastic underbody cladding, which gives protection against stones, water and soiling, makes it possible to dispense with a conventional PVC underbody coating. The wheel arch claddings of three-millimetre thick plastic likewise give protection against stone impact.

Mercedes-Benz also makes a major contribution to exemplary long-term quality and value retention with an innovative, more scratch-resistant clear paint coat based on nano-technology. This innovative paint system, which had its world debut with Mercedes-Benz, is standard equipment for the new M-Class; it is used for both metallic and non-metallic paint finishes.

Thanks to remarkable advances in the science of nano-technology it has been possible to integrate ceramic particles measuring less than one millionth of a millimetre into the molecular structure of the paint binder. These nano-particles achieve a three-fold increase in the scratch-resistance of the paint finish, ensuring a visibly improved and lasting sheen.

Front-end structure with crash-boxes and robust structural members

Dispensing with the previous structural frame has made it possible to design the front-end structure of the new M-Class to passenger car standards. This particularly benefits occupant safety during a frontal collision.

Two straight side members of high-strength steel reinforced with two interior sheet steel liners, a front element and two outside members above the wheel arches are the most important energy-absorbing features of the front end. Energy is absorbed in stages, depending on impact severity. The front end is equipped with two crash boxes of high-strength steel which absorb most of the impact energy in the event of a frontal collision at low speeds (up to 15 km/h).

The crash boxes are bolted to the side members and can therefore be inexpensively replaced without welding in the event of damage. All the other components in the front end are also bolted together for ease of repair.

Only at higher impact speeds (above 15 km/h) are the robust side members in the front end activated to form a deformation zone. If the body structure is subjected to one-sided loads, i.e. during an offset frontal impact, an aluminium section and other transverse connections in the front end ensure that the impact forces are also dissipated to the unaffected side of the vehicle. During an offset crash the second level of side members above the wheel arches also serves to dissipate impact energy.

The high-strength steel subframe which carries the front axle, steering gear, engine and transmission is also specifically deformed during an impact, and thereby makes a major contribution to energy absorption. The front wheels are also integrated into the safety concept; during a collision they are supported by the robust side walls and direct impact forces away from the passenger cell.

Effective all-round occupant protection

While the front-end structure is designed and constructed to deform and absorb energy during an accident, the passenger cell of the new M-Class forms a protective area with a high deformation resistance. The floor assembly, roof pillars, side members and side walls are the most important components of this rigid safety zone:

• The main floor consists of three assemblies. The centre section - the transmission tunnel - has a higher steel thickness and therefore acts as the backbone of the floor structure. The areas on both sides of the tunnel are reinforced with cross-members which provide a solid mounting base for the seats and ensure a high level of lateral stability, which particularly benefits occupant protection in the event of a lateral collision. In addition a diagonal member extending from the firewall to the B-pillars strengthens the floor assembly.
• The external side panels and multi-piece interior side wall components form the multi-layered cross-sections of the roof pillars, roof frame and side members.
• The reinforced outer shells of the side walls are one-piece units; the inner shells consist of several steel sheets which are particularly robust at the nodal points where the roof pillars join the roof frame and the side members.

In addition to aero-acoustics, sound-absorbing foam components contribute to the excellent noise comfort on board the new M-Class. These are concealed at various points of the bodyshell - 34 such foam elements are integrated into the two side walls alone.

Easily repaired rear-end design

The rear side members of the new M-Class are designed a continuous, closed box sections with gradually reducing material thickness. These make a major contribution to occupant safety during a rear-end collision. The fuel tank is located in an impact-protected position in front of the rear axle.

In the interests of repair-friendly design the rear end also features steel crash boxes and a deformable aluminium cross-member. These absorb impact forces during minor collisions (up to a maximum of 15 km/h) so that the downstream body structure remains undamaged. Bolted connections allow damaged crash boxes and the cross-member to be replaced inexpensively.

The world's first off-roader with PRE-SAFE® anticipatory occupant protection

With adaptive front airbags and belt force limiters, belt tensioners, sidebags and windowbags, as well as newly developed crash-responsive head restraints (optional), the M-Class is well-prepared for all types of accident where occupant protection is concerned. But the developers of the off-roader were not satisfied to leave it at that. They are offering customers an even more intelligent system which can already become active in the few seconds preceding an impending accident: PRE-SAFE®.

With this anticipatory occupant protection system, which Mercedes-Benz first realised in the S-Class in 2002, the M-Class underlines its role as a trendsetter and example. No other off-roader offers this unique, trailblazing technology.

PRE-SAFE® creates the link between active and passive safety. It is networked with Brake Assist and the Electronic Stability Program (ESP) and recognises critical handling situations which might lead to an accident. PRE-SAFE® intervenes in such dangerous situations within milliseconds, preparing both the occupants and the vehicle for the possible collision:

• The seat belts of the driver and front passenger are tensioned as a precaution.
• If the electrically adjustable front passenger seat with memory function (optional) is in an unfavourable position in terms of longitudinal adjustment and cushion/backrest angle, it is moved to a better position.
• The sunroof is closed if a rollover threatens.

Thanks to these precautionary PRE-SAFE measures the vehicle occupants are in a better seating position even before the accident occurs, enabling the seat belts and airbags to work more efficiently. If the accident is avoided, the preventive tensioning of the seat belt is automatically relaxed and the passengers are able to return the seat and sunroof to their previous positions.

Adaptive airbags and belt force limiters

The restraint systems also respond according to need on the basis of an efficient sensor system. In addition to the central crash sensor in the centre console, Mercedes-Benz employs so-called up-front sensors for this purpose; these are located on the radiator cross-member in the front end structure, and their remote positioning in the front end of the body enables them to detect the severity of a collision even earlier and with greater accuracy. This makes it possible to shorten the time that elapses between the moment of impact and the deployment of the airbags and belt tensioners even further. In other words, the seat belts are tensioned at a very early stage so that the occupants are optimally linked to the passenger cell and take part in the vehicle deceleration process during an impact.

The electronic control unit also uses the up-front information to deploy the driver and front passenger airbags sooner as the situation demands. This takes place in two stages, depending on the severity of the impact: during a minor frontal impact the electronic control unit only ignites one stage of the two-stage airbag gas generators, and the airbag inflates more gently. Should the control unit detect a severe frontal collision, however, it deploys the second stage of the gas generator after a slight delay. As a result, the airbags inflate at a higher pressure to provide the occupants with the level of protection required in a collision of this severity. By virtue of a newly developed, absorbent and telescopic steering column which compresses by up to 100 millimetres during a collision, the driver is given far more space for forward motion.

The belt force limiters are also adaptive, i.e. they operate according to the accident situation: if the sensors send information that a frontal collision is severe, the seat belts are tensioned and reach their maximum retaining power. Briefly afterwards the force limiters switch to a lower level of force, which slackens the belts slightly and allows the front occupants to sink more deeply into the airbags. This reduces the loads acting on the chest area.

Newly developed, crash-responsive NECK-PRO head restraints

Mercedes-Benz has perfected occupant protection during a rear-end collision with newly developed, crash-responsive NECK-PRO head restraints for the driver and front passenger (optional), which celebrate their premiere in the M-Class. These are likewise linked to the control unit: if the sensor system detects a rear-end collision with a defined impact severity, it releases pre-tensioned springs inside the head restraints which immediately cause these to move forward by approx. 40 millimetres and upwards by 30 millimetres. This means that the heads of the front occupants are supported at an early stage, reducing the risk of whiplash injuries. After NECK-PRO activation the head restraints can be unlocked and returned to their original position using a tool supplied as an accessory.

Sidebags and windowbags as standard

With standard sidebags for the driver and front passenger, as well as windowbags, the restraint system of the new Mercedes-Benz M-Class provides two further, highly-effective systems whose protective effect is complementary: while the sidebags primarily reduce the loads acting on the chest area, the windowbags provide extended head protection for both front and rear occupants. During a lateral impact the windowbag inflates and extends from the front to the rear roof pillar like a large curtain. Accordingly it also gives protection against objects which might penetrate into the vehicle interior during a crash. Sidebags are also optionally available for the rear.

A special sensor system is responsible for deployment of the sidebags within milliseconds: in addition to the central sensor in the interior, satellite sensors located in the side members provide information about the severity of a lateral collision.

The sophisticated crash sensor system in the new M-Class is rounded off by a rollover sensor which activates the belt tensioners and windowbags during certain types of lateral impact. A special, laminated coating on the weave ensures that the windowbags remain inflated for some time after a rollover.

Cd-value reduced by 15 per cent

A low fuel consumption, a high level of handling safety, good noise comfort - the excellent results the new M-Class can boast in these disciplines is also the result of painstaking, detailed work in the wind tunnel. Designers, aerodynamics specialists and engineers from other areas worked together closely to ensure that the off-roader was at its best in every respect, and with convincing results:

• The coefficient of air resistance (Cd) is 0.34, which is 15 per cent below the figure for the preceding series. This means that the new M-Class has the lowest air resistance of any off-roader.
• Mercedes engineers have reduced the lift at the rear axle (cAH) to 0.033 - 70 per cent less than for the previous M-Class - making an important contribution to exemplary handling stability, safe braking and good directional stability.

These results are the culmination of various aerodynamic measures in almost every area of the bodyshell, but these advances are also based on the latest test procedures, which allow a particularly realistic analysis of the airflow characteristics. The wind tunnel tests on the new M-Class were carried out at the University of Stuttgart, with the wheels turning: two steel belts powered the wheels to simulate the aerodynamic interaction between the road surface, the tyres and the bodywork, for example to examine the influence of turning wheels on the air resistance and lift forces - particularly at high speeds.

Major details which contribute to the exemplary Cd-value include the following:

• The aerodynamically efficient shape of the front apron directs the airstream to the sides for an optimal flow around the front wheels. This component was extended to the rear so as to cover part of the engine compartment and prevent turbulence from developing around the engine itself. In the diesel models the engine compartment is fully encapsulated.
• Effective sealing around the radiator grille. This improves the airflow while making more efficient use of the cooling air.
• The exterior mirror housings, whose shape was optimised in the wind tunnel.
• The wheel spoilers reduce lift forces.
• The smooth underfloor cladding extending from the engine compartment to the rear axle. This ensures that the airstream is able to flow beneath the body without turbulences. The areas beneath the fuel tank and between the exhaust silencers are also covered with plastic cladding.
• The rear apron is equipped with a special diffuser between the exhaust tailpipes.
• The optimised spoiler edge on the tailgate, the air flow break-away edges on the rear side windows and the rear lights specifically influence the airstream.

Aero-acoustic analysis according to a noise index

Aerodynamics is a discipline with many aspects. Research in the wind tunnel not only affects fuel consumption and handling safety, but also the level of comfort experienced by the vehicle occupants - the noise comfort. The airstream flowing around the car at speed can make itself felt in many ways, and impair travelling comfort with loud hissing, high-frequency whistling or sonorous booming. It is the task of aero-acoustic specialists to analyse and assess this background noise and eliminate the sources of intrusive sounds. The progress they have made is audible in the new M-Class.

The doors were a particular focal point for the aero-acoustic technicians. Care was already taken during the design stage to ensure that the outer and inner skins for a rigid, vibration-resistant structure by virtue of various reinforcing sections, and that the window frames in particular are extremely robust. In this way airstream-induced movement of the window frames at high speed was reduced by more than half. In addition the door edges feature a continuous double seal - and in some areas even a triple seal - to ensure that no wind noises are audible. The side windows also make a major contribution to noise insulation: the glass thickness has been increased by 0.3 mm to 4.1 millimetres versus the preceding series.

The roof pillars, roof trim strips and exterior mirror housings were also subjected to aero-acoustic examination using special microphones, then contoured so that no disturbing wind noises are generated.

Mercedes engineers summarise the individual results of these aero-acoustic measures in the form of a noise index. This not only takes measured values such as volume and frequency into account, but also the subjective perception of noises which may not be loud but can certainly be irritating. The noise index for the new M-Class has been lowered to 50, which is an approx. 50-per-cent reduction versus the preceding series and matches the exemplary level for the E Class. The new M-Class therefore occupies a peak position among off-roaders in terms of noise comfort as well.

Unimpaired visibility in the rain

Aerodynamics also make an important contribution to driving safety with measures which allow the driver a unrestricted visibility through the front side windows in the rain. Mercedes engineers achieved this by directing the rainwater to the rear, downwards or to the sides. In the new M-Class the side windows in the driver's main field of vision remain clear because the rainwater hitting the windscreen is collected in drainage channels on the A-pillars, then conducted to the rear across the roof with the help of the slipstream and drained away downwards by a channel at the rear edge of the roof. This even works well during a heavy downpour. The housings of the exterior mirrors are designed in such a way that rainwater flows to the outside in an unobtrusive, continuous channel and drains away.

Windscreen wipers from the wind tunnel

The windscreen wipers of the new M-Class were also developed in the wind tunnel: they are known as aero-wipers. Instead of the articulated retention system used for conventional wiper blades, in which the rubber blades are claw-mounted, the aero wiper consists of a one-piece rubber section with an integral spoiler and externally mounted spring rails; these precisely follow the curve of the windscreen. The spring rails ensure an even distribution of wiper pressure along the entire length of the wiper blade, so that it always operates with the greatest possible contact pressure. The result is significantly better wiping quality, even in heavy snow. Dispensing with the conventional claw-mounted system, which is prone to icing in winter conditions, reduces the installed height of the wiper by almost half. This produces a noticeable reduction in windscreen wiper noise.

The new M-Class is equipped with an efficient two-arm wiper system with special kinematics: while the left wiper arm moves around a fixed axis, its counterpart on the right executes and additional lifting movement to wipe an even larger area of the windscreen. This provides the driver with optimal visibility. A rain sensor is standard equipment in the off-roader.

Bi-xenon headlamps with Active Light System and cornering light function

Good visibility means a high level of safety. In view of this, Mercedes engineers have also improved the headlamps of the M-Class. In addition to the standard halogen projection headlamps for high and low beam, which are automatically switched on or off by a sensor on the windscreen, foglamps in the bumper cladding and ambient lighting in the mirror housings, other high-tech lighting systems are optionally available for the new off-roader. The bi-xenon headlamp package offers two additional functions which make driving even safer in the dark:

• Active Light System: The headlamps follow the steering movements of the driver and rapidly pivot to the relevant side when the car enters a bend. This improves road illumination by up to 90 per cent: whereas the normal illumination range when entering a bend with a radius of 190 metres is approx. 30 metres, this increases by a further 25 metres with the new headlamp technology. Because the light distribution corresponds to the current steering angle, the driver recognises the course of a bend sooner than with conventional low-beam headlamps. Active headlamps work both on high and low beam.
• Cornering light function: This function is activated when the driver uses the indicators or turns the steering wheel, and illuminates the side area ahead of the vehicle to an angle of up to 60 degrees with a range of approx. 30 metres. In this way the cornering light function make areas of the road visible which would remain dark with conventional headlamp technology when turning a corner. This means that pedestrians and cyclists can be seen clearly even in the dark. The driver also has better orientation when negotiating bends at slow speeds (up to 40 km/h). The oval lamps of the cornering lights are accommodated in the bumper cladding; they also function as foglamps.

The equipment package containing bi-xenon headlamps, Active Light System and the cornering light function also includes dynamic beam control and a headlamp washer system using high-pressure water jets.

Suspension: Top-class technology for the motorway and off-road

Whether taking bends at speed, on long motorway journeys or on difficult terrain, the suspension of the new M-Class is equal to any challenge. Mercedes engineers have newly developed the axles, steering, brakes and suspension, and adapted them to match the varied operating requirements of the off-roader. The result is a technical masterpiece which meets the highest demands in terms of both handling dynamics and ride comfort. Individual customer wishes can now also be met with respect to suspension technology: available options include an AIRMATIC package with the Adaptive Damping System (ADS) and the Offroad Pro technical package with differential locks, low-range ratios, an underride guard and AIRMATIC with extended functions for even greater ground clearance.

The front wheels are located by a newly developed double-wishbone suspension whose upper wishbone is located in a high position. In conjunction with the robust subframe, engine, transmission, steering and axle, this suspension principle has enabled Mercedes engineers to achieve an ideal compromise between a high load-bearing capacity, good ride comfort and exemplary handling characteristics. The upper wishbone is of forged aluminium, while the lower wishbone and steering knuckle are of nodular cast iron. Four rubber bearings isolate the subframe from the vehicle body and make a major contribution to the vibration comfort of the new M-Class.

This front suspension with its high control arm is equipped with spring struts whose longer spring travel and more effective rubber bearings provide better ride comfort than the preceding series. The spring struts contain cylindrical coil springs, single-tube gas-pressure shock absorbers and large head bearings. The torsion bar stabiliser is attached to the spring strut by a linkage.

Speed-sensitive steering as standard

The steering gear of the new M-Class is positioned in front of the wheel centre, and therefore where it can support the slight but easily controlled understeer of the off-roader 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 speed-sensitive steering, which continuously reduces the steering effort below 100 km/h 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 than when driving on the motorway, where the speed-sensitive steering provides good road contact. This comfort feature is standard equipment in the new Mercedes off-roader.

Mercedes-Benz has developed a four-spoke steering wheel with a diameter of 385 millimetres for the M-Class whose diecast 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 keys, 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, which is able to collapse telescopically by up to 100 millimetres during a frontal collision, can be individually adjusted for height and reach. Electric adjustment is also available as an option.

Newly developed four-link technology at the rear axle

Like the front axle, the rear axle is mounted on a subframe which is effectively isolated from the bodyshell by two rubber bearings and two hydro-mounts. Mercedes engineers have developed a four-link suspension design which mainly consists of the following elements:

• Lower wishbone: This axle component is made from nodular cast iron.
• Upper steering arm: This is an assembly of sheet steel camber arms and forged steel rods.
• Track rods: These are located behind the wheel centre and are of welded tubular construction.

The rear axle coil springs and single-tube shock absorbers are positioned in line. A torsion bar stabiliser is also used.

AIRMATIC air suspension in on-road and off-road configurations

The AIRMATIC air suspension system (optional) developed by Mercedes-Benz proves its versatility in the new Mercedes-Benz M-Class. It not only makes a significant improvement to ride comfort, but also offers additional functions for off-road driving.

Mercedes customers are offered a choice: the AIRMATIC package provides an air suspension configured for on-road operation which automatically lowers the suspension by 15 millimetres at higher speeds. For off-road driving this system enables the ground clearance to be increased by 80 millimetres at the touch of a button. The second AIRMATIC variant, which is part of the Offroad Pro technical package, enables the vehicle level to be raised in three stages by operating a button: by 30, 80 and 110 millimetres. This gives the new M-Class its maximum ground clearance of 291 millimetres.

It is possible to raise or lower the suspension both when idling or on the move. If the M-Class is moving, the system operates on a speed-dependent basis and automatically lowers the suspension by 15 millimetres at both axles when 140 km/h is reached, in order to reduce the air resistance and improve handling stability. When the speed falls below 40 km/h the suspension is raised to its normal level again. 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 fully loaded.

Adaptive shock absorber control according to the driving situation

In both variants AIRMATIC Standard works together 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. The so-called 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 e.g. 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 characteristic curves 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 M-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 diving movements of the vehicle body. The current driving situation is identified by means of a steering angle sensor, three body-mounted acceleration sensors, the speedometer signal giving the road speed, data from the Electronic Stability Program (ESP®) and the signal from the brake pedal switch. On the basis of this information the electronic control unit calculates the most efficient damping forces and selects the relevant characteristic curves for the shock absorbers.

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 M-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.

Larger front and rear brake discs

The new M-Class features generously dimensioned, internally ventilated front brake discs. In the six-cylinder models these have a diameter of 330 millimetres - 27 millimetres more than before. The top-of-the-line ML 500 is equipped with even larger brake discs (350 millimetres). At the rear axle Mercedes-Benz uses solid disc brakes with a diameter of 330 millimetres - 45 millimetres more than in the previous M-Class.

Sports package with 19-inch light-alloy wheels

Wide-base tyres and 17 or 18-inch light-alloy wheels underline the sporty, dynamic appearance of the new Mercedes-Benz M-Class. The six-cylinder models are fitted with 17-inch light-alloy wheels in a seven-spoke design and size 235/65 R 17 wide-base tyres as standard. The ML 500 has 18-inch light-alloy wheels in the five-spoke "impeller" design and size 255/55 R 18 tyres. A different 18-inch wheel in a five twin-spoke design with 255/55 R 18 tyres is optionally available for all the model variants.

The wheels Mercedes-Benz offers in conjunction with the sports package are even larger and more attractive: these 19-inch light-alloy wheels in a five-spoke design are also optionally available in a chrome-plated version which creates an additional visual highlight.

ESP® with tyre pressure warning function

ABS, ASR, ESP®, Brake Assist - these well-proven dynamic safety systems developed by Mercedes-Benz are standard equipment in the new M-Class.

The Electronic Stability Program not only keeps the off-roader safely on course, but also monitors the tyre pressures in its latest version: 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 Mercedes-Benz M-Class.