Mercedes-Benz presented the M-Class W 164 model series at the North American International Auto Show in Detroit in January 2005. In February 2005 the off-roader premièred in Europe at the Geneva International Motor Show. The W 164 was launched in the USA in spring 2005 and in the European market in summer 2005. The all-new W 164 model series M-Class was built in the Tuscaloosa (Alabama) factory and replaced its predecessor, model series W 163 which had also been produced in the USA. In total, 647,738 model series 163 vehicles were built. Most successful among the first-generation models was the ML 320, of which 282,614 were sold. This corresponded to 43 percent of the total output. Between 1997 and 2004, the M-Class became established as a trendsetter in the new Sports Utility Vehicles (SUV) market segment.
Mercedes-Benz further consolidated this market position with the model series W 164. The company’s engineers took the successful off-road concept and further enhanced its performance under both on-road and off-road conditions. Instead of the ladder-type frame used for model series 163, the new M-Class now boasted an integral body construction. Due to the high loads experienced when driving off road, several aspects of the design, including the points of force application between the chassis and the body, were fully redesigned. This meant that the body exhibited much greater torsional stiffness than on the predecessor models. Even greater levels of ride comfort over long distances were achieved thanks to contributions such as redesigned axles, smooth-running six and eight-cylinder engines and optional AIRMATIC air suspension.
When the new M-Class hit the market, three of the four engines available were new developments. The ML 280 CDI (140 kW/190 hp) and ML 320 CDI (165 kW/224 hp) made use of a new V6 diesel engine with two power stages. This V6 offered third-generation common-rail direct injection and the latest piezo injector nozzles. In the ML 320 CDI, the engine generated a maximum torque of 510 newton metres from 1600 rpm (440 newton metres in the ML 280 CDI). Fuel consumption was 9.4 litres per 100 kilometres (NEDC combined consumption), elevating the new M-Class to a position among the most economical off-roader vehicles in its class. Also new on the block was the V6 petrol fitted to the ML 350 with 200 kW (272 hp) and a maximum torque of 350 newton metres. At the top of the engine range was the eight-cylinder unit in the ML 500 which now delivered 225 kW (306 hp). These drive systems outperformed their predecessors in terms of power and torque by up to 38 per cent. State-of-the-art powertrain technology and bodywork with good aerodynamics (Cd = 0.34 instead of 0.40 previously) combined to reduce fuel consumption by 10 per cent.
The unique 7G-TRONIC seven-speed automatic transmission was fitted as standard in all models of the new M Class. Shifting was controlled to ensure that the transmission exploited the engine’s potential for high performance to the best possible effect, while at the same contributing significantly to fuel economy. Operation of the 7G-TRONIC system was initiated electronically via a selector lever positioned close to the steering wheel using new DIRECT SELECT technology. Additional steering-wheel shift buttons allowed rapid manual shifting through the seven gears. The DIRECT SELECT gearshift on the steering column rendered the conventional automatic selector lever in the centre console obsolete. This made it possible to completely redesign the tunnel trim. Now, instead of a selector lever, there was space for a roomy stowage compartment plus a cupholder.
New safety benchmarks were defined by the updated off-roader. Occupant protection was based on large front and rear deformation zones provided by the integral body construction, as well as on cutting-edge technologies adopted from the luxury segment and now fitted as standard. Among these technologies were adaptive two-stage airbags for the driver and front passenger, front side airbags, window airbags, emergency belt tensioners and belt-force limiters for all seats. In the event of a rear impact, the new NECK-PRO crash-responsive head restraints (optional extra) offered additional protection for the driver and front passenger.
Moreover, the Mercedes-Benz off-roader set a new standard in its class with the inclusion of PRE-SAFE® preventive occupant protection (optional extra). This multi-award-winning technology was activated in critical hazardous driving situations to prepare the vehicle and its occupants for an imminent collision. PRE-SAFE® provided precautionary tensioning of the driver and front-passenger seatbelts, moved the optional power front-passenger seat to a better position by sliding it forwards/backwards and changing the angle of the cushion and backrest, and closed the optional sliding sunroof if the vehicle was at risk of overturning.
Such preparations for a possible accident were made possible because of the synergy of active and passive safety that PRE-SAFE® achieved – something that was unique at the time. The system was networked with the anti-lock braking system (ABS), brake assist system (BAS) and Electronic Stability Program (ESP®), whose sensors could already detect dangerous driving manoeuvres. With PRE‑S AFE®, Mercedes-Benz also made use of this sensor data for the purpose of preventive occupant protection.
Similarly typical of the brand were the long-term qualities of the new M-Class. Its fully galvanised body was also additionally protected against corrosion in many places with an organic coating. Structural areas subject to high loads were sealed with a cavity protection agent and folds with seam sealant. Thanks to extensive plastic underfloor panelling, the Mercedes-Benz engineers were able to dispense with the usual underbody protection. Newly developed paint based on nanotechnology was part of the standard package. Mercedes-Benz was the first in the world to introduce this technology in series production. It offered a substantial improvement in scratch resistance compared with conventional standard and metallic paints, as well as a noticeably better shine.
The off-road performance of the permanent all-wheel drive was improved by Mercedes-Benz with enhancements to the 4ETS traction system which now came with additional features such as off-road ABS, start-off assist and Downhill Speed Regulation as standard. To meet the varying needs of different drivers, all-wheel drive was offered in two equipment configurations on the M-Class. In addition to the basic version, an optional Off-Road Pro Engineering package was available for those who wished to tackle the most challenging off-road scenarios. Among other features, this incorporated a two-stage transfer case with low-range reduction gear, a manually or automatically selectable 100-percent inter-axle lock and an identical lock on the rear axle. Also included was AIRMATIC air suspension, modified for off-road use, which could be used to increase ground clearance by 110 millimetres to 291 millimetres (predecessor: 204 millimetres) and wading depth to 600 millimetres (previously: 500 millimetres). Air suspension also provided a considerable boost to ride comfort, so Mercedes-Benz also offered the technology in an optional on-road version too. AIRMATIC was combined with the Adaptive Damping System (ADS) as standard to control damping according to the driving situation. This meant that the M-Class reached new levels of driving dynamics and ride comfort.
Mercedes-Benz engineers had also developed a new front and rear axle for the M-Class. The front wheels were controlled by a double-wishbone suspension, whose high-positioned aluminium wishbones played an important role in delivering exemplary driving dynamics and low road roar and tyre vibration. At the rear, the new axle was constructed using a four-link design. Light alloy wheels with wide-base tyres of size 235/65 R 17 (V6 models) and 255/55 R 18 (V8 models) augmented the sporty look of the M-Class.
With its interplay of strongly contoured surfaces and taut lines, the design characterised the confident nature of the M-Class. The design idiom emphasised sportiness with a flat windscreen, distinctive wings and shoulder lines ascending to the rear. These accents were further stressed by the proportions of the bodywork. Compared with its predecessor model, the W 164 came in 150 millimetres longer (4780 millimetres), 71 millimetres wider (1911 millimetres) and 5 millimetres lower (1815 millimetres with roof rails). Increased by 95 millimetres, the wheelbase was now 2915 millimetres.
Typical Mercedes-Benz quality was evident in the interior too. Occupants were treated to higher quality materials than ever before, surfaces with even better touch and feel, and a significant increase in inside space benefiting all seating positions. Compared with the predecessor model, the distance between the front and rear seats was increased by 15 millimetres to 880 millimetres, making it comparable to a luxury-segment saloon. For passengers in the rear, legroom improved by 35 millimetres and elbowroom by 32 millimetres.
Customers purchasing the new M-Class had a choice of seats to match their individual comfort requirements. As an alternative to the standard front seats, which included electric adjustment of height and backrest and cushion angles, optional sports seats with specially shaped backrests could be ordered. Seat backs and cushions of the rear seats were split 60:40 and were folding. If required, both seat cushions could be removed to create a level load area measuring over 2.10 metres in length. Maximum cargo volume was 2050 litres (VDA measuring method), which was much greater than that of comparable offerings from competitors. The tried-and-tested EASY‑PACK system was retained to simplify loading and unloading. Optional extras for the system included a power tailgate and an equipment package for safely securing loads.
Advanced assistance systems from the Mercedes-Benz luxury segment provided helpful driver aids, while at the same time increasing comfort and safety. For example, at the customer’s request, Mercedes-Benz would equip the M-Class with the newly developed THERMOTRONIC multi-zone automatic air conditioning system, PARKTRONIC parking assist and the COMAND APS control and display system with Europe-wide DVD navigation. Bi-xenon headlamps with active curve illumination and cornering light function (optional extra) increased safety when driving in the dark.
Towing was another task for which the M-Class was excellently suited. Whether it was a caravan, boat or horse trailer, the driver could safely master critical driving situations even with a load attached to the trailer coupling. This was no coincidence: right from the design phase, the chassis, braking system and steering of the W 164 model series were all engineered with towing loads in mind. When an M-Class was ordered with a factory-fitted trailer coupling, the customer enjoyed the extra benefit of Mercedes-Benz ESP® Trailer Stability Assist. The purpose of this additional Electronic Stability Program (ESP®) function was to improve safety when driving with a trailer. Not only could the system detect much-feared pendulum movements, it was also able to reduce them effectively. It achieved this by analysing the ESP® sensor data and applying the brakes to individual wheels in a specific, alternating pattern to stabilise the car/trailer combination.
Right from market launch, the M-Class was also offered in powerfully dynamic AMG livery. Unmistakable AMG body design and striking 19-inch AMG light-alloy wheels could be supplied with any of the off-roader’s engine variants, furnishing the M-Class with a distinctive, sporty look. In familiar AMG style, the body design included front and rear aprons painted in vehicle colour. The front apron had distinctive edges and vertical brushed stainless steel inlays, which gave the M-Class an even wider and lower stance. Accompanying this were generously dimensioned round fog lamps with chrome surrounds and optional cornering light. Four air intakes with black, motorsport-style metal mesh grilles underpinned the dynamic character of the AMG body design. To accentuate the sturdy character of the off-roader further still, the underride guard had an expressive design with vertical contours.
Bulges on the rear apron that accommodated the tailpipes of the two-pipe exhaust system gave the AMG-styled M-Class a broader, more muscular look. A brushed stainless-steel load sill guard prevented the rear apron from being scratched when loading luggage. 8.5 x 19 AMG light-alloy wheels painted in sterling silver were the perfect complement to the AMG body design.
By July 2005, just a few days after market launch in Western Europe, around 26,500 orders had already been placed for the M-Class. In the United States of America, the major market for the premium off-roader, the M-Class had launched with great success in early April and contributed significantly to the successful sales figures generated by Mercedes-Benz USA.
At the IAA International Motor Show (IAA) in Frankfurt am Main in September 2005 Mercedes-Benz presented the new top-of-the-range engine option for the W 164 model series in the form of the ML 63 AMG. The market launch followed in the second quarter of 2006.
The ML 63 AMG was powered by a 6.3-litre V8 AMG engine packing a mighty 375 kW (510 hp). This AMG engine was the most powerful series-produced naturally aspirated eight-cylinder engine in world, developing a maximum torque of 630 newton metres at 5200 rpm. The unique combination of high-revving engine and large displacement coupled a thrilling love to rev with strong pulling power at low engine speeds.
From rest, the AMG off-roader could reach 100 km/h in just 5 seconds, while the top speed was 250 km/h (electronically limited). Compared with its predecessor, the 255-kW (347-hp) ML 55 AMG with 510 newton metres of torque, the ML 63 AMG offered a 46 per cent power boost and 23 per cent more torque. Power transmission was handled by an AMG SPEED-SHIFT 7G‑TRONIC automatic gearbox with a DIRECT SELECT selector lever positioned close to the steering wheel. Three shift programmes, carefully tailored to match the sporty power delivery of the engine, ensured every ounce of available power could be exploited. Each shift programme was selected via a switch in the centre console, marked “S” (Sport), “C” (Comfort) and “M” (Manual) to indicate the characteristics and speed of the associated gearshifts.
An AMG sports suspension based on the AIRMATIC air suspension allowed high-speed, high-precision cornering with little body roll, while still maintaining ride comfort over long distances. The air suspension featured dedicated AMG spring struts and a specially tuned Adaptive Damping System (ADS). A level control system automatically lowered the body at high speeds.
Contact with the road was taken care of by 19-inch AMG 5-spoke light-alloy wheels. As an option, 20-inch AMG light-alloy wheels in a 5-spoke design with 295/40 R 20 wide-base tyres could be fitted. Decelerating the ML 63 AMG was the job of the large, high-performance brakes with vented and cross-drilled brake discs all round.
The design of the ML 63 AMG made a clear visual statement about its high-ranking status. Characteristic of the AMG body design were the front and rear aprons, the AMG-specific radiator grille, wheel-arch flarings, stainless-steel running boards with rubber studs and darkened tail lamps. An AMG sports exhaust system with two chrome-plated twin tailpipes attested both visually and acoustically to the power and dynamism of the top-of-the range M-Class model. Sportiness was the order of the day in the interior too, with nappa leather upholstery, Alcantara inserts in the shoulder area, heated seats with multicontour backrest, an ergonomic AMG sports steering wheel with gearshift buttons, AMG door sills, stainless-steel sports pedals with rubber studs and an AMG instrument cluster with special lettering, red needles and 320 km/h on the speedometer.
A long-distance test conducted in the USA in summer 2005 by Auto-Bild magazine demonstrated the commendable fuel efficiency of the M-Class. On completion of the coast-to-coast marathon from New York to San Francisco, a distance of around 5200 kilometres, the ML 320 CDI had consumed an average of 9.1 litres of diesel per 100 kilometres. This corresponded to an economy advantage of more than 1 litre per 100 kilometres over a slightly less powerful petrol vehicle with hybrid drive.
Safety was another area where the 2005 M-Class made its mark. In National Highway Traffic Safety Administration crash tests, the off-roader performed superbly. The M-Class, one of the first SUVs ever to be evaluated, received the maximum five-star US-NCAP rating in both frontal and side impact tests. For the US version of the NCAP (New Car Assessment Program) test, vehicles had to withstand a frontal crash into a solid wall at 35 mph (56 km/h). The SINCAP test (Side Impact New Car Assessment Program) demanded a collision with a 1368 kilogram deformable barrier at 38.5 mph (62 km/h) on the side of the vehicle at the same height as the front seat occupants.
The off-road capabilities were put to the test when the M-Class entered the January 2006 Dakar Rally. Former Mercedes-Benz works driver Ellen Lohr joined the ORC Sport Service team from Nellingen, together with Detlef Ruf, in a prototype based on the new M-Class. Team ORC Sport Service developed the vehicle independently under the leadership of Hans Baur and design engineer Andreas Lennartz.
In summer 2006 Mercedes-Benz presented the new top-of-the range diesel, the ML 420 CDI 4MATIC. To maintain consistency in the designations used across all model series, from 2006 onwards the 4MATIC designation was also added to those M-Class vehicles that featured all-wheel drive as standard. Features of the V8 diesel engine in the ML 420 CDI 4MATIC included four-valve technology, bi-turbocharging and variable turbine geometry. Torque from the gutsy 225-kW (306-hp), 3996-cc engine was 700 newton metres between 2000 and 2600 rpm. With the new V8 diesel engine, performance increased compared with the ML 400 CDI of the predecessor model series, mainly thanks to the third-generation common-rail high-pressure injection system that raised injection pressure to a maximum of 1600 bar and ignition pressure to 175 bar.
From rest, the ML 420 CDI 4MATIC could accelerate to 100 km/h in 6.8 seconds, while the top speed was 235 km/h. To accelerate from 60 km/h to 120 km/h in third gear, the top-end diesel needed 6.0 seconds. Combined with the standard seven-speed 7G‑TRONIC automatic gearbox, the high level of reserve power made for relaxed driving in higher gears, thereby reducing fuel consumption too. When driven with fuel economy in mind, the new engine used just 9.1 litre of diesel per 100 kilometres; average fuel consumption was a moderate 11.1 litres per 100 kilometres. Raw emissions, which were already low on this model, were reduced by a further 99 percent thanks to the inclusion of a maintenance-free diesel particulate filter. As such, the off-roader’s emissions came in well below the Euro 4 limits.
Towards the end of 2006 the American Insurance Institute for Highway Safety (IIHS) selected the M-Class as its Top Safety Pick 2007. Pitted against a field of luxury SUVs, the off-roader from Stuttgart achieved outstanding results in all areas. Each year, the experts at IIHS categorised new vehicle models according to stringent safety criteria; in 2006, sports utility vehicles (SUVs) were included in the mix for the first time. Tests included rear-end collisions, as well as front and side impacts. This was the first year that vehicles had to feature an Electronic Stability Program (ESPÒ) in order to be considered a Top Safety Pick. The technology reduced risk of skidding while cornering and also helped keep the vehicle travelling in the desired direction in extreme situations, such as on black ice or in the wet. ESP® has been standard equipment on all Mercedes-Benz passenger vehicles since 1999.
Mercedes-Benz presented a new V8 petrol engine for the M-Class in 2007. Displacement in the ML 500 4MATIC engine was increased to 5461 cc, with corresponding rises in power and torque to 285 kW (388 hp) and 530 newton metres respectively. These performance gains translated to improved driving performance. Acceleration from rest to 100 km/h in the ML 500 4MATIC now took 5.8 seconds, meaning that it achieved the speed benchmark more than 1 second faster than its predecessor. However, greater engine output and improved performance did not come at the expense of fuel economy. On the contrary, the NEDC combined fuel consumption was now 0.6 litres less, at 12.8 litres of premium petrol per 100 kilometres.
July 2007 saw Mercedes-Benz present the Edition 10 special M-Class model. This was to celebrate ten years of production of the M-Class, which at the time was the best-selling premium SUV from Mercedes-Benz, with over 850,000 sales. Until its replacement by the all-new model generation in 2005, the first generation of the M-Class achieved worldwide sales of around 600,000 units. The W 164 model series continued this success, with around 250,000 Mercedes-Benz customers deciding to buy the updated off-roader by summer 2007.
Among other features, the Edition 10 variant offered 20-inch wheels, bi-xenon headlamps, dark-tinted tail lamps, special titanium-look bodywork highlights and special Edition 10 logos on the wings. The tasteful and sporty two-tone all-leather interior featured sports dials and stainless-steel sports pedals. Edition 10 vehicles could be ordered from autumn 2007. A total of five variants of the special model were available: the high-torque ML 420 CDI 4MATIC V8 diesel with 700 newton metres, the V6 diesel models ML 280 CDI 4MATIC and ML 320 CDI 4MATIC, and the ML 350 4MATIC and ML 500 4MATIC with petrol engines.
In November 2007 the one-millionth vehicle – an M-Class – rolled off the line at the Mercedes-Benz plant in Tuscaloosa, Alabama, where the M-Class had been produced since 1997. The GL-Class (model series X 164) and R-Class (W/V 251) had been built alongside the M-Class W 164 in the same factory from the time of their introduction.
March 2008 marked the arrival of the new generation of the model series 164 M-Class from Mercedes-Benz.