BACKGROUND

The original 1998 Mercedes-Benz M-Class entered the sport utility vehicle sector, one of the fastest-growing and most competitive market segments of the 1990s.  At the time, the M-Class sport utility was far more than just another entry in a highly competitive market segment. It represented new thinking and a new attitude as well as a new design and production process.  The M-Class also marked the apex of an unparalleled new-product offensive that began with the first C-Class sedan in 1994 and continued for the next decade.  The original M-Class started the trend toward SUVs with a more car-like ride that swept across the entire auto industry, and now the new-generation M-Class is poised to reaffirm its leadership of the fast-growing market segment it established in 1997.

M-Class Started an Industry Trend

The first-generation M-Class set new standards by combining the safety, quality, performance and comfort of a Mercedes-Benz with the versatility of a sport-utility and exceptional off-road capability.  Unusual for the time, the M-Class was designed from the ground up as an SUV rather than being based on an existing truck platform.  Mercedes-Benz had extensive experience building four-wheel-drive vehicles such as the Gelandewagen and Unimog for off-road use.  However, rather than re-designing or re-badging an existing vehicle, the M-Class project began with a "clean sheet of paper." Most important, it combined off-road prowess with the refinement and security of a Mercedes-Benz passenger car.

 "Clean Sheet of Paper" Design

Research into the project began in the early 1990s.  Results indicated that owners of truck-derived sport utility vehicles were pleased with the ruggedness and cargo capacity that their vehicles offered, but they also wanted a more comfortable ride, better fuel economy, greater passenger safety and improved reliability.

Unique at the time in the retail SUV market, M-Class featured front and rear independent double wishbone suspension, combined with a separate, welded steel box frame to optimize handling and comfort both on and off-road. 

New Four-Wheel Drive, V6 Engine

From a technical standpoint, the original M-Class featured an entirely new four-wheel-drive system, combining full-time drive to all four wheels with four-wheel traction control and a low range.  This unique setup eliminated the need for differential locks, required no driver intervention and provided far more responsive handling and steering under all driving conditions.  The 1998 M-Class also marked the debut of the company's first V6 powerplant.

U.S. Assembly Plant

While Mercedes-Benz cars were manufactured under license in the United States from 1905-1907 by the Steinway Piano Company, the M-Class production site in Tuscaloosa, Alabama was the first real passenger vehicle production facility in the United States for Mercedes-Benz. 

During the eight-year life cycle of the first-generation vehicle, more than 570,000 M-Class SUVs were produced at the plant.  The plant has now undergone a $600 million (U.S.D.) expansion that doubles production to 160,000 vehicles a year, doubles the workforce to 4,000, and doubles its size to about three million square feet.  The plant now includes two assembly shops, two paint shops and an expanded body shop.

SUV Market Overview

Although the sport-utility vehicle can trace its roots back to the 1940s, it was the introduction of so-called "compact" four-door SUVs in the early 1980s that ignited the immense popularity of these vehicles across diverse demographic and psychographic lines.  The sport-utility vehicle (SUV) segment has been one of the most rapidly growing parts of the overall automobile market in Canada. 

In particular, the premium segment, defined as SUVs priced more than $35,000, has experienced considerable growth.  Within this sub-segment are luxury versions of lower-priced SUVs, as well as specific luxury-brand SUVs, some of which are modified and rebadged versions of other vehicles.

SUVs are popular with singles, with couples, with families and with empty-nesters.  The popularity of SUVs owes to many factors, including versatility for passengers and cargo, four-wheel drive capability for inclement weather driving and/or off-road travel, and, not insignificantly, an outward image that conveys an active outdoors-oriented lifestyle.  This image has become an important buying consideration, and is likely to continue playing a major role in purchase decisions of these vehicles.

Introduction

The all-new 2006 M-Class is strikingly different from all angles, both outside and inside.  The second-generation sport utility vehicle is characterized by an aggressive wedge shape complemented by sweeping front fenders with projector beam headlights, dramatic shoulder lines and a sharply angled windshield.  The interior is completely redesigned to provide more comfort and more user-friendly space.

New M-Class Sales Began in Spring 2005

The new M-Class went on sale in Canada during spring 2005 and in Europe later this past summer. The new sport utility is 150 mm longer, 71 mm wider and 6 mm lower on the road than its predecessor, with a 2,915 mm wheelbase that's 93 mm longer as well for greater comfort.  Beneath the aerodynamic exterior is an all-new unit-body platform as well as new suspension that delivers improved on-road performance and comfort.

On-Road and Off-Road Capability

While the new M-Class has clearly evolved toward a more on-road orientation, an optional off-road package available later in 2006 provides the versatile vehicle with more off-road capability than ever before.

Useful Technology Abounds

New and useful technology abounds in the 2006 M-Class, including a standard seven-speed automatic transmission, an even more effective full-time four-wheel-drive system and optional features such as height-adjustable AIRMATIC air suspension.  A revised four-wheel traction control system now incorporates functions such as a downhill driving aid and a hill-holder.

A Choice of V6 and V8 Power

The second-generation M-Class is available with a choice of two powerful engines that define two distinct models.  The ML350 4MATIC™ all-wheel drive is powered by a new-generation 3.5-litre, four-valve-per-cylinder V6 engine delivering 268-horsepower and 258-lb.ft. of torque.  The ML500 4MATIC™ all-wheel drive has a higher level of standard equipment, including a five-litre V8 engine with 302-horsepower and 339-lb.ft. of torque.

A Roomier, Sportier Interior

  Inside, a completely new interior is marked by a sport-oriented instrument panel, a multifunction steering wheel and instrument cluster, rich interior materials and significantly improved spaciousness for all five seating positions.  By comparison, there's over 50 mm of additional front leg room, and rear-passenger knee and leg room have also been increased by 35 mm and 33 mm respectively.

Continuing the Mercedes-Benz commitment to occupant safety, the 2006 M-Class comes standard with two-stage adaptive air bags for the driver and front passenger, curtain side air bags as well as belt tensioners and belt force limiters for all seating positions.  A rollover sensor can deploy the belt tensioners and the curtain air bags if the vehicle senses an imminent rollover.

The original M-Class started the trend toward more premium SUVs with a more car-like ride that swept across the entire auto industry, and now the new-generation    M-Class is poised to reaffirm its leadership of the fast-growing market segment it established in 1997.

EXTERIOR DESIGN

An Aggressive Wedge Shape

Wider, longer, lower -- the all-new M-Class makes a bold statement.  Exterior styling is characterized by an aggressive wedge shape, complemented by sweeping front fenders, dramatic shoulder lines and a sharply angled windshield.  Widely flared rear wheel arches and a horizontal body line work in concert with the angled "C-pillar" to emphasize a sense of forward motion.

Athletic Exterior

The athletic design theme is reinforced by the dynamic appearance of the front grille, which features three wide louvers with pronounced air vents complemented by the chrome Mercedes-Benz star. Strong horizontal lines on the grille also emphasize the new sport utility's nearly 76 mm wider stance (when compared to its predecessor).  The front bumper features an aluminium-look front under-guard with recessed square openings.  Two ventilation grilles on the hood incorporate the signature three fins found on many classic and contemporary Mercedes-Benz cars, and help to underline the dynamic qualities of the new M-Class.

Viewed from the rear, the wide track and flared rear wheel arches continue the muscular design theme, while twin tailpipes and a prominent rear spoiler provide a strong visual reminder of the new model's performance potential.

Distinct Character for V6 and V8 Models

The V6-powered ML350 4MATIC™ all-wheel drive models are predominantly identified by a black painted grille (silver painted grille when equipped with optional Appearance or AMG Sport Package) with chrome ribs and standard seven-spoke alloy wheels mounted on 235/65 R17 tires. 

The V8-powered ML500 4MATIC™ all-wheel drive models feature a silver painted grille with chrome ribs, chrome door handles, tailgate trim and side molding, and standard 5-spoke 18-inch alloy wheels.  Larger 19-inch wheels are available on both models as part of the optional AMG Sport Package or Appearance Package.

Projector Beams Light the Way

The front-end styling is accentuated by eye-catching projector-beam headlights, comprised of three individual chrome tubes. Optional Bi-Xenon active curve-illuminating headlights combined with corner-illuminating front fog lights provide enhanced visibility. These swiveling headlights follow the steering input of the driver to rapidly pivot to the relevant side when the car enters a bend, improving road illumination by up to 90 percent over fixed lights in turns.  When the driver activates the turn signal or turns the steering wheel (below 40 km/h), the corner illuminating fog lights illuminate areas of the road which would remain dark with conventional lighting systems – areas that could include a pedestrian or cyclist.

INTERIOR DESIGN

Rich, Sporty, Attention to Detail

The interior of the new M-Class has been completely redesigned and features high-quality materials finished with craftsman-like attention to detail.  Once inside, the driver is greeted by a new four-spoke multifunction steering wheel with brushed aluminium accents on the lower spokes. 

Behind the steering wheel is a new Mercedes-Benz electronically controlled gear selector mounted on the steering column to control the standard seven-speed automatic transmission. 

A sport-oriented instrument panel is horizontally divided into an upper and lower section in both form and colour.  Four round circular vents are positioned at the left, centre and right sections of the sweeping dash, their chrome surrounds reminiscent of the engine housings found on jet aircraft. 

The upper section of the dashboard arches over the instrument cluster, which is dominated by angled tubular gauge binnacles containing the speedometer and tachometre as well as fuel gauge and clock. 

Redesigned for More User-Friendly Space

The clearly arranged centre console features easily accessible and well-positioned ergonomic controls and displays.  Located just below the two central air vents is a second-generation MCS II entertainment head unit (or optional COMAND system) and new standard Thermatic dual-zone climate control.  The MCS II head unit also incorporates a single CD slot (auxiliary input for MP3 players in glove box).  Audiofiles will appreciate the optional harman/kardon Logic 7 system audio system featuring a glove-box mounted 6-disc CD changer. 

Equal Parts Form and Function

The centre console extends gracefully around the centre transmission tunnel, which includes two large cupholders with the ability to hold two 32-oz. cups or one      44-oz. cup.  Two integrated grab handles on the console echo the sweeping lines of the exterior and provide a firm gripping point for those occasional ventures on rough roads or on no roads at all.     

The two-tone colour scheme of the interior is repeated on the centre console, transmission tunnel and door panels, accented by bird's eye fine line, burl walnut or aluminium trim (depending on options chosen).  The door panels are concave in form at elbow level, thereby increasing elbow room, while their pronounced contours add a unique element of style.  

The interior passenger compartment is configured in a five-passenger arrangement, and the 60:40 split second row is now easier to fold when the need arises.  Customers can select from standard cloth or optional leather seating inserts on ML350 4MATIC™ all-wheel drive models while ML500 4MATIC™ all-wheel drive models feature standard leather seating inserts or optional leather.  Optional Appearance package feature suede-like Alcantara seating and aluminium interior trim.

More Space, More Comfort 

            While onlookers admire the new M-Class from the outside, passengers will appreciate the significantly improved spaciousness of all five seating positions.  In fact, the distance between the front and rear seat is increased by more than ½ inch (15 mm) than that of the outgoing model, achieving a level of comfort more often found in luxury sedans.  Knee room has been increased by nearly 1 ½ inches (35 mm) and elbow room by over an inch (32 mm).

ML350 4MATIC™ V6 Engine

The new M-Class is available with a choice of two powerplants that define two distinct models.  The ML350 4MATIC™ all-wheel drive is powered by a new-generation 3.5-litre twin-cam V6 engine that produces 268 horsepower, while the ML500 4MATIC™ all-wheel drive comes with a single-cam 5.0-litre V8 that makes 302 hp.

Variable Valve Timing

On the 3.5-litre V6, variable intake and exhaust valve timing requires separate camshafts for the intake and exhaust valves, so the new powerplant (first used in the 2005-model SLK350) represents the first time Mercedes-Benz has used double-overhead camshaft technology on its V6 engines.  Valve timing can be automatically adjusted within a range of 40 degrees using electro-hydraulic vane-type adjusters.

At part throttle, the valve timing adjuster keeps the exhaust valves open as the intake valves are opening, using this valve overlap for internal exhaust gas recirculation, reducing exhaust emissions and improving fuel economy.  However, approaching full throttle, the camshaft adjustment optimizes valve timing for maximum power.

To minimize interfering with air flow through the ports, valve stems are only six millimetres or about ¼ inch in diametre (most valves have 8 or 10 mm stems), and the valves are angled at 28.5 degrees to optimize the combustion chamber shape. 

Improved Fuel Efficiency, More Power

The 3.5-litre aluminium V6 produces 268 horsepower and 258 foot-pounds of torque, with maximum torque available from 2,400 rpm all the way up to 5,000 rpm.  In fact, at just 1,500 rpm the new V6 develops 87 percent of its maximum torque!  While the variable valve timing system gets a lot of credit for the engine's unusually broad torque curve, a two-stage intake manifold plays a key role as well.

Two-Stage Intake Manifold Fattens the Torque Curve

  The intake manifold is made of a lightweight magnesium alloy.  At relatively low engine speeds, a set of flaps in the manifold close off short intake passages, forcing intake air to take a much longer route into the engine.  This creates pressure waves that help the intake process and improve torque at lower engine speeds.

Above about 3,500 rpm, the flaps open, and intake air flows the shortest distance to the combustion chambers, helping to generate maximum horsepower, especially at higher speeds.

Tumble Flaps Improve Fuel Efficiency

  The ML350 4MATIC™ all-wheel drive engine is equipped with newly developed tumble flaps in the intake passages near the combustion chamber.  The tumble flaps pivot open under partial load, improving combustion by creating additional turbulence around the intake valve and in the combustion chamber.  During higher engine loads such as full throttle, the tumble flaps are completely recessed in the wall of the intake manifold.  Better combustion helps improve engine torque, but the primary purpose of the tumble flaps is to further increase fuel economy, and tests show that the tumble flaps indeed boost fuel efficiency by about two percent.

Assembling the New Engine from Start to Finish

First, a forged crankshaft with four main bearings is placed into an aluminium engine block that features wide main-bearing saddles and transverse bearing supports that minimize vibration.  A balance shaft is then installed in the block between the two cylinder banks, about where the camshaft is located on a pushrod-type "V" engine. 

The balance shaft is driven from the crankshaft by a long double chain that loops around one camshaft in each cylinder head and engages the underside of the balance shaft sprocket.  This means the balance shaft counter-rotates at crankshaft speed, and its "lobes" cancel out the inherent imbalance and vibration of a 90-degree V6.

Iron-coated aluminium pistons are pinned onto forged steel connecting rods that are about 20 percent lighter than on comparable engines.  The pistons slide into the cylinders, and the connecting rods are clamped around the crankshaft journals. 

When the aluminium engine block is pressure-cast, its cylinder bores are etched to make a long-life, low-friction running surface for the piston rings. 

The two cylinder heads are bolted onto the block, and twin camshafts are installed in each cylinder head.  The intake camshafts are driven by a double chain, and gears on the intake cams drive the exhaust camshafts.

Even Downstream Emission Controls are Elegant

Double-wall exhaust piping is used to keep the exhaust air as hot as possible leading to twin catalytic converters located just below the engine.  Further downstream, two more catalysts help promote afterburning of carbon monoxide and unburned hydrocarbons.  With the help of secondary air injection, the catalysts promote downstream conversion of pollutants into carbon dioxide and water vapor, and two oxygen sensors for each catalyst monitor and help manage the entire process.

ML500 4MATIC™ Engine

  The ML500 4MATIC™ all-wheel drive engine is a 5.0-litre 90-degree V8 with a single overhead camshaft in each cylinder bank.  This engine architecture features twin spark plugs and three valves per cylinder – two intakes and one large exhaust valve.

Three-Valve Technology

            Three-valve-per-cylinder technology can reduce exhaust emissions, especially during the critical warm-up stage.  Catalysts must heat up to work effectively, and modern engines must heat up quickly. 

In the 5.0-litre V8, combustion heat in each of the large, single exhaust valves is dissipated through a sodium-filled valve stem, while exhaust heat is retained and insulated by double-wall piping in the exhaust manifold.  The seamless double-wall manifold is made by using high-pressure liquid-forming technology for greater durability and lighter weight.

Spark Plugs Provide a One-Two Punch

            Using one less exhaust valve also makes room for two spark plugs per cylinder, and an innovative offset-phase twin-plug ignition system is matched to the three-valve technology.  Among other things, the dual ignition system activates the two spark plugs in each cylinder, one after the other in quick succession (rather than simultaneously), with varied "stagger," depending on engine load and speed.  This phase-shifted twin-plug sequence (as well as the basic ignition timing) changes after each combustion cycle for extremely precise control of the combustion process.  This also enables combustion chamber pressures to be closely controlled to minimize combustion noise without sacrificing efficiency.

Low-Friction Silicon-Aluminium Cylinder Sleeves

            Mercedes-Benz was the world's first automaker to use innovative cast-in silicon-aluminium cylinder sleeves with a low-friction surface that allows piston-ring spring tension to be reduced by 50 percent. 

Thanks to a number of such friction-reducing measures, internal "drag" is 45 percent lower than other engines.  The efficiency payoff for low internal friction means both fuel savings and increased power. 

    Now used in most Mercedes-Benz engines, this sleeve technology is also designed to provide exceptional block stiffness while minimizing weight.  The sleeves are more than 454 grams lighter than conventional iron sleeves, which makes for extremely lightweight components. 
Modern Modular Assembly

            Key to a modular engine approach is the ability to manufacture six- and eight-cylinder engines under the same roof, with as many standardized components as possible, providing for increased output, which further reduces costs.  As a result, a full range of V6 and V8 engines – all with a standard distance between cylinders of 106 millimetres or 4.2 inches – is produced at the engine plant in the Stuttgart suburb of Bad Cannstatt.

TRANSMISSION

The World's First Seven-Speed Automatic on an SUV

The new M-Class comes with the world's only production seven-speed automatic transmission. When compared to the previous transmission generation, the seven-speed makes the SUV both faster and more economical while providing smooth, barely noticeable gearshifts.  

Seven gear ratios provide a wider spread of ratios between first gear and top gear and, at the same time, allow smaller increases in engine speed as the vehicle accelerates through the gears.  This gives the electronic control unit more flexibility in terms of maximizing fuel economy and making the transmission's reaction time extremely fast.

Skip a Gear When You Need To

    Unlike most transmissions, the seven-speed transmission will skip up to four gear ratios if necessary when it downshifts, shifting directly from seventh to fifth, for example, or even sixth to second.  This helps the transmission choose the perfect gear ratio for quick acceleration and ensure smooth, almost imperceptible shifts in the process.

Lock It Up for Better Fuel Mileage

New to the M-Class, the Mercedes-Benz seven-speed uses a refined, proven hydrody­namic torque converter with a special lock-up clutch inside the converter for maximum fuel efficien­cy.  The lockup clutch eliminates the usual torque converter "slippage," providing the direct connection and fuel efficiency of a manual transmission when the lockup clutch is engaged. 

In the seven-speed, the lockup clutch engages in all seven gears. (To put that into perspective, many cars lock up the converter only in top gear.)  The Mercedes-Benz lock-up clutch is submerged in transmis­sion oil and uses special long-life friction materials.

Where's the Shifter?

One of the most noticeable differences in the interior of the new M-Class is the lack of a shift lever on the centre console!  Thanks to the latest electronic control technology, a small stalk on the right side of the steering column now serves the purpose.

Shift control is simpler than ever.  Lift the stalk up for reverse, push down for drive, and push a button on the end for park. Once underway, pushing either one of the shift buttons on the "back" of the steering wheel provides Touch Shift manual gear changes.

While all Mercedes automatics feature Touch Shift, the new layout on the M-Class further improves its usability.  As on all Touch Shift cars, it isn't necessary to move the shift lever to another gate to make manual gear changes – in fact, the selector lever positions for forward gears are gone.  Though gears can be manually selected, computer control prevents downshifts that would cause the engine to overrev.  

Full-Time Four-Wheel Drive

The M-Class uses three conventional "open"differentials in the front, rear and centre of its 4MATIC™ all-wheel drive full-time four-wheel-drive powertrain.  The centre differential allows the front wheels to go faster than the rear when turning, while the front and rear diffs permit the outside wheels to go faster than the inside ones in turns.

Four-Wheel Traction Control

The Mercedes-Benz M-Class stands apart from many other four-wheel-drive SUVs by using a four-wheel adaptation of the company's proven electronic traction control to maintain stability and traction on wet or snowy roads.  The  4MATIC™ all-wheel drive all-wheel drive system senses wheel slip electronically and brakes the slipping wheels, which transfers torque to those tires with the most grip, on virtually any road surface. 

Unlike many conventional four-wheel-drive systems, the 4MATIC™ all-wheel drive system automatically provides mobility even when three wheels lose traction.  Maneuverability is enhanced, both on and off-road, and in tight steering situations there is no axle "binding,"which the driver would experience as sluggish steering response and vibration.

The centre differential is located in a transfer case, along with a link chain which turns a prop shaft to the front differential.  In vehicles equipped with an optional off-road package (coming later in 2006), a planetary unit in the transfer case provides two selectable gear ranges – 1:1 for on-road use and a 2.93:1 low-range gear reduction for off-road travel.

Under ideal road and driving conditions, torque distribution is 50 percent front/50 percent rear, so the driver experiences the benefits of full-time four-wheel-drive.  In slippery or off-road conditions, the benefit of the full-time system is obvious. 

Yet, even on perfectly dry highways, the system makes its presence known by giving the M-Class secure, neutral handling characteristics.  When road conditions turn slippery, or when the driver heads off-road, 4MATIC™ all-wheel drive can vary torque transfer front-to-rear and side-to-side to be directed to the wheels with traction.  In practice, all available torque can even be transferred to one wheel.

Low-Range Transfer Case for More Off-Road Capability

An optional off-road package coming later in 2006 features a two-speed electronically controlled transfer case that gives the Mercedes-Benz M-Class more off-road capability than ever before.  High range provides 1:1 on-road gearing, and selecting "Low"with a button on the instrument panel engages a 2.93:1 ratio.

Unlike the previous model, shifting into low range will be possible while moving – as long as vehicle speed is below 45 km/h, and the shift lever is in neutral.  Shifting back into high range is possible at any speed below 72 km/h.

In low range, and first gear, the Mercedes M-Class equipped with the off-road package has one of the lowest "crawl speeds" in its class, giving it the ability to negotiate the most challenging terrain and steep descents.  When in low range, the    M-Class seven-speed automatic transmission uses a special shift program to provide smooth shifting in rugged off-road conditions.

Differential Locks

The off-road package will also include a rotary switch on the centre console that can engage electronically controlled multi-disc locks on the centre and rear differentials. The switch can also select an automatic mode that locks the centre differential whenever it senses wheel slippage.

Off-Road Mode

Standard equipment on all M-Class vehicles, an Off-Road button on the centre console activates the following features:

• ABS: Available at speeds below 32 km/h, the on-off cycling of the anti-lock brake system keeps the brakes engaged more of the time, which purposely locks the wheels and digs into loose surfaces to stop more quickly.  Braking distances on loose surfaces are noticeably shorter in the Off-Road mode.
• Traction control: Not unlike the off-road ABS mode, slightly more wheel slip improves traction in gravel or sand.  
• Automatic transmission: Shift points are raised so that the M-Class stays in the relevant gear longer.
• Engine: The electronic throttle valve opens more slowly when the accelerator pedal is depressed, allowing vehicle speed to be controlled more easily.

DSR – Cruise Control for Steep Descents
Downhill Speed Regulation is essentially a low-speed cruise control system for steep descents, which is especially helpful in off-road conditions.  The driver then uses the cruise control stalk to set the speed anywhere between 6 and 19 km/h, which is activated by another button on the centre console.  The system uses throttle, transmission gearing and automatic braking to help maintain vehicle speed.  The descent speed can also be set by using the multi-function steering wheel and a special menu in the central display.

Start-Off Assist
This new hill-holder technology helps to keep the M-Class from rolling backward on steep uphill grades.  If the slope is steep enough, a special inclination sensor allows the system to hold brake pressure when the driver switches from the brake to the gas pedal.  Brake pressure is released automatically when the driver accelerates, helping the vehicle to start up steep grades more safely.
The start-off assist is also active on steep descents, which is often helpful in hilly off-road conditions.
 

Body

New Unit-body Platform

            The Mercedes-Benz engineers who undertook the design of the second-generation M-Class re-examined and analyzed every component – nothing remained sacred.  One of the most dramatic departures from the original design is its structural frame. 

Instead of a separate “ladder-type” frame and body shell, the new M-Class features a self-supporting unit-body platform.  To handle the high load forces involved in off-road driving, the high-stress points between the suspension and body have been redesigned and – above all – made stronger.

Better Torsional Rigidity

            One indication of the result is the new body’s higher torsional rigidity, which is now measured at 2.18 mm per metre – significantly better than its predecessor.  As a result, the new M-Class boasts noticeably improved vibration comfort and excellent handling stability.

“D-Ring” Design Has a Firm Grip on the Body
            A continuous “D-Ring” roof structure contributes to the body’s outstanding rigidity. This robust connection from the floor, sidewalls and roof frame is also used to attach the rear liftgate.
            In general, the new body is about 150 mm longer, nearly 71 mm wider and about 6 mm lower.  The wheelbase is 93 mm longer, and there’s 57 mm more rear overhang.

Five Times More High-Strength Alloy 
While conventional steel continues to dominate the materials mix, the new       M-Class body uses five times more high-strength alloys than the previous model!  In terms of weight, 62 percent of the body panels are now formed from high-strength steel.
Some of these alloys, in particular “dual-phase” steel, even fall into the very high strength category.  The two-phase microstructure of this alloy can withstand very high loads and, as a result, contributes to the strength of the front end and passenger cell.

Low-Stress Welding
            The flanges on many of its steel panels are designed so that any tolerances are already compensated for when the sheets are positioned, which allow them to be welded together with less metal stress.  This technique also contributes to corrosion protection because it eliminates most of the extra brazed and MAG welding seams, which can be vulnerable to corrosion.

Fully Galvanized Body Panels
Every body panel in the new M-Class is zinc-galvanized and organically coated on both sides.  The coating also contains rust-preventing zinc pigments.
Many structural areas of the body receive cavity protection, and welding seams are carefully sealed.  A six-section plastic undercladding provides protection against stones, water and dirt, eliminating the need for any conventional PVC undercoating.  Thick wheel well cladding (3 mm thick) also helps protect against stones and gravel.

Nano-Particle Paint Protection
An innovative clear-coat technology that debuted on Mercedes-Benz products has significantly increased the scratch resistance of the paint!  Standard on all M-Class metallic and non-metallic colours, the new process integrates ceramic particles measuring less than a millionth of a millimetre into the molecular structure of the paint, producing a more durable, glossier sheen.

Chassis

Four-Wheel Independent Suspension

The M-Class features independent front and rear suspension.  Four-wheel independent suspension endows the M-Class with class-leading handling, stability and ride comfort, both on and off-road, along with lower noise levels.
Compared to solid axles, independent suspension reduces unsprung weight by two-thirds, resulting in both better handling and ride quality.  In addition, wheel travel on one side does not change camber of the opposite wheel as with a solid axle.
Double Wishbone Front Suspension
The M-Class front suspension features newly developed upper and lower control arms in a double-wishbone configuration.  The upper arms are mounted very high in the chassis and are made of high-strength, light-weight forged aluminium alloy, which further reduces unsprung weight, while the lower control arms and steering knuckle are nodular cast iron. 
The front suspension uses spring struts with coil springs, gas shocks and large head bearings, and a stabilizer bar attaches to the lower control arms.
A front subframe is attached to the unit-body by four large rubber bushings.  The subframe carries the engine, transmission, rack and pinion steering gear and the lower control arms, while the upper control arms and shock/spring units are attached directly to the M-Class body.  The front differential housing is attached by three large noise-insulating rubber mounts.

Four-Link Rear Suspension
Similar to the front, the rear suspension is mounted to a subframe that is isolated from the body by two solid rubber bushings and two hydro-mounts that are filled with a liquid that helps to dampen vibration

            Mercedes-Benz engineers have developed a new four-link rear suspension that consists of the following parts:

                        1. Forged steel upper rods
                        2. Sheet steel camber arms
                        3. Cast iron lower wishbones
                        4. Tubular steel track rods
Separate shock absorbers are positioned behind the coil springs, and a stabilizer bar completes the picture.

Rack-And-Pinion Steering

The Mercedes-Benz M-Class employs a rack-and-pinion steering unit that’s mounted ahead of the front wheel centre.  The hydraulically assisted steering has a variable ratio that operates more directly, or slightly faster, in the centre position.
In addition, the new M-Class steering is available with a speed-sensitive feature. An electronic valve ensures full power assist at low speeds for easy parking and low-speed turns, and the valve reduces the amount of power assist at higher speeds for improved road feel through the steering.

Serious Brakes
            The new ML350 4MATIC™ all-wheel drive comes with large 13-inch (330 mm) vented front and solid rear disc brakes, while the ML500 4MATIC™ all-wheel drive is equipped with even larger 13.8-inch (350 mm) vented front discs, with 13-inch (330 mm) vented discs at the rear.  Both models have twin-piston brake calipers up front and single-piston calipers at the rear.
Wheels and Tires
Wide, low-profile tires with a relatively wide track underscore the sporty nature of the new M-Class.  The ML350 4MATIC™ all-wheel drive has 17-inch seven-spoke light-alloy wheels shod with 235 / 65 R 17 tires, and the ML500 4MATIC™ all-wheel drive comes with 18-inch five-spoke wheels with 255 / 55 R 18 tires.  Either model can be fitted with optional 19-inch five-spoke wheels with 255 / 50 R 19 tires.
Height-Adjustable Air Suspension
            Developed by Mercedes-Benz, optional AIRMATIC air suspension not only improves M-Class ride comfort, but also provides impressive flexibility by reducing ride height on the highway, increasing it off-road, maintaining vehicle level when loaded and continuously adjusting the suspension damping as road conditions change.  The driver can also select three different levels of damping.
            Above 120 km/h, the AIRMATIC system automatically lowers ride height more than ½ inch (15 mm) for improved handling and stability, as well as less air drag and, as a result, better fuel mileage.  When speed falls below 40 km/h, the suspension returns to normal height.  On rough roads or off-road, a rocker switch on the dash allows the AIRMATIC system to increase vehicle height by more than three inches (80 mm), so that ground clearance is increased to nearly 10 ½ inches – 261 mm.
Adaptive Damping System
AIRMATIC air suspension includes an adaptive damping system that can actually change compression and rebound damping every 0.05 second in response to changing road conditions.  If the system senses small body movements, it maintains a comfort mode with relatively soft damping.
With more body movement, the system uses solenoid valves in the shocks to cycle automatically between hard rebound and hard compression modes.  A rocker switch on the dash can lock the suspension into a “sport” mode – hard rebound and hard compression.  The switch has three positions, which also allows it to lock in the comfort mode or maintain automatic operation.  In summary:

• Stage 1 – the “comfort” setting, with soft compression and rebound damping
• Stage 2 – soft rebound and hard compression damping
• Stage 3 – hard rebound and soft compression damping
• Stage 4 – the “sport” setting, with hard rebound and compression damping

The AIRMATIC system features air bladders instead of coil springs, and ADS gas shock/air spring struts are used in the front of the M-Class.  In the rear, ADS gas shocks are located behind the air springs.

Safety

Crumple-Zone Body Design

Mercedes-Benz safety engineers have designed the unit-body platform of the new M-Class to take advantage of the latest occupant safety technology.  Two longitudinal members of high-strength steel (reinforced with inner steel liners), a front element and two more members above the wheel wells are the key energy-absorbing features of the new front end.
Two crash boxes of high-strength steel bolted to the longitudinal members are designed to absorb most of the impact energy in low-speed frontal collisions.  As a result, the crash boxes and a number of other bolt-on components can be replaced less expensively without welding.
At higher speeds, the longitudinal members form a key part of the crumple zone that absorbs more impact energy.  In an offset frontal collision, an aluminium bulkhead and several other transverse members are designed to spread the forces across the entire front end.  Side members above the wheel wells serve as a second level of energy absorption in offset frontal collisions.
            A high-strength steel subframe that carries the engine, transmission, steering and front suspension is also designed for controlled deformation in a severe frontal collision, and even the wheels play a role.  Supported by the strong side walls, the wheels help absorb some of the crash forces.

A High-Strength Passenger Cell
While the front and rear of the new M-Class are designed to deform and absorb crash energy, the super-strong passenger cell protects its occupants by maintaining survival space.  The floor, roof pillars, longitudinal members and side walls frame this rigid safety zone.
The transmission tunnel is formed of thick steel and serves as the backbone of the floor structure.  Transverse cross members connect to the tunnel and provide high lateral strength in a side impact, as well as a solid mounting point for the seats.  In addition, diagonal members extend from the front bulkhead to the B-pillars to further strengthen the floor.
External side panels and multi-piece interior side panels help to form and strengthen the roof pillars, roof frame and side members.  As an aside, sound-absorbing foam contributes to impressively low noise in the new M-Class, and 34 such foam sections are incorporated just in the two side walls.
Rear Crumple Zones, Too
            The rear longitudinal members of the new M-Class are made of continuous closed box sections with tapered thickness for low weight and maximum strength in a rear collision.  The fuel tank is located in a protected area in front of the rear wheels.
            Like the front, the rear also features bolt-on steel crash boxes and an aluminium cross-member that absorb impact energy in low-speed collisions, which can be replaced in a relatively simple and lower-cost procedure.

Seat Belts, Belt Tensioners and Belt-Force Limiters
The new M-Class is fitted with three-point, inertia-reel seat belts for all five seating positions, as well as electronically controlled belt tensioners and belt-force limiters for the four outboard seats.  In a collision that exceeds the deployment threshold, the tensioners take up slack on the seat belt to increase the effectiveness of the seat belt by allowing restraining contact between the belt and occupant earlier in the collision sequence.  Later in the sequence, belt force limiters can somewhat limit the restraining force of the seat belt against the occupant, reducing the risk of chest and shoulder injuries.

Two-Stage Front Air Bags
Two-stage front air bags for the driver and front passenger feature two inflation rates, depending on the severity of impact and other factors such as the weight category of the front seat occupant.  For example, if sensors detect a front-end impact that exceeds the activation threshold for an average occupant, only one chamber of the gas generator is deployed.  In a more serious frontal collision, a second chamber is deployed 5 to 15 milliseconds later to increase the inflation rate of the air bag. 

Side Impact Protection
The new M-Class is equipped with standard window curtain air bags – devices that can help cushion front and rear occupants when their heads hit the side windows or roof pillars in a side collision.  In addition, the air-filled cushion can block glass splinters or other objects that could cause injury in a side impact or rollover.  Over 180 cm long, 355 mm in height and about 50 mm thick when inflated, a window curtain air bag on each side of the car can deploy in about 25 milliseconds from the ceiling and extends across both front and rear side windows. 

Many severe and often fatal head injuries in side collisions are due either to an occupant’s head striking the interior or to the whiplash movement of the head toward the window or side/roof pillars.  Crash tests with the curtain air bag indicate about a 90 percent reduction in the forces likely to cause head injuries.
The new M-Class also comes with door-mounted side air bags for the front and rear seats that protect the torso and work in conjunction with the curtain air bags. 
A Highly Advanced Sensor System
A highly advanced sensor system gives the restraint system excellent reflexes.  Two sensors in the nose of the M-Class (on the radiator cross member) provide initial collision data, and can deploy the belt tensioners before the primary sensor in the cabin could react.  These upfront sensors can also provide data to the system’s central processing unit earlier in the collision sequence, helping it determine whether or not both stages of the front air bags should deploy.
Satellite sensors in the lateral cross members under the seats work together with the central crash sensor to deploy air bags in the event of an actual collision that exceeds the deployment threshold.
Sensors in the front passenger seat are used to determine the passenger’s weight category and the inflation rate of the air bag deployment is varied accordingly. 

Rollover Sensor
            The new M-Class is also equipped with a rollover sensor, which can recognize this type of accident and relay the information to the restraint systems’ central control.  If the sensor detects a rollover, the central control unit activates the belt tensioners and curtain air bags.

Tire Pressure Monitoring
Mercedes-Benz inventions such as ABS anti-lock brakes, all-speed traction control, Electronic Stability Program (ESP) and Brake Assist are standard on all Mercedes-Benz passenger vehicles, including the new M-Class.  However, the 2006 sport utility has a new feature that makes clever use of existing wheel speed sensors for ABS and ESP.
Since an under-inflated tire is smaller and rolls slightly faster to keep up with the other three, the system uses wheel speed signals to identify under-inflated tires and alert the driver.  In effect, the ESP system not only helps to keep the car safely on course but now also keeps an eye on tire pressure.

ML350 4MATIC™ all-wheel drive Standard Equipment

Performance

n          All-new unit-body design

• 3.5-litre DOHC V6 engine with 268 horsepower and 258 lbs./ft. torque

n          Driver-adaptive electronically controlled seven-speed automatic transmission
n          Full-time four-wheel-drive with 4-Wheel Electronic Traction System (4MATIC™ all-wheel drive)
n          4-wheel independent suspension
n          4-wheel 330 mm disc brakes with 4-channel Anti-Lock Braking System (ABS)
n          17-inch seven-spoke aluminium alloy wheels
n          235 / 65 R17 all-season performance tires

Safety and Security

• Safety cell and crumple zone body

n          Driver and passenger two-stage adaptive front air bags
n          Door-mounted side air bags in front and rear
n          Central locking system
n          Automatic anti-theft alarm
n          Illuminated entry system

Exterior
n          Halogen headlamps with high-impact polycarbonate lenses
n          Dual heated power side-view mirrors
n          Rear-window defroster
n          Single-lift tailgate/door
n          Rear wiper

Interior

• Multifunction steering wheel (and dash display)
• Second-generation modular COMAND system (single CD slot and aux audio input)
• Power front seats
• Power windows on front and rear doors with express down and up (on door panel)
• Easy fold-down rear seat (60:40 split for passenger and cargo versatility)
• Air conditioning with dust filter

n          Cruise control
n          8-speaker audio system with AM/FM/Weatherband CD stereo and integrated controls for CD changer
n          Factory pre-wiring for optional CD changer and integrated cellular telephone
n          Full instrumentation including speedometer, tachometer, fuel and coolant temperature gauges, electronic digital odometer, resettable trip odometer and quartz clock
n          Delayed-shutoff front courtesy lamps
n          Four reading lights
n          Rear seat and cargo-area courtesy lights
n          Illuminated visor vanity mirrors
n          Front centre armrest with two-level storage
n          Two front console cupholders
n          Dual rear cupholders
n          Storage pockets in dash, doors and front of console
n          Retractable cargo cover

Additional ML500 4MATIC™ all-wheel drive Standard Equipment

• 302-horsepower 5.0-litre SOHC V8 Engine
• Larger brakes
• 18-inch five-spoke wheels with 255 / 55 tires
• Heated Seats
• Silver grille with chrome ribs
• Chrome door handles, tailgate trim and side molding
• Electrically adjustable steering column
• Burl walnut interior trim
• Parameter speed-sensitive power steering
• Power folding mirrors
• Rain sensor
• Blue-tinted sport glass
• Privacy glass
• Roof Rails
• Homelink

Options
                                  

• Appearance Package (includes Alcantara interior)
• Height-Adjustable AIRMATIC Air Suspension (with ADS Adaptive Damping System)
• Bi-Xenon Active Curve Illuminating Headlights (with corner illuminating front fog lights)
• harman/kardon Logic 7 audio system with six disc CD changer (in glove box)
• Cargo Management System
• Power Glass Sunroof
• Keyless-Go
• Parktronic
• Power Liftgate
• DVD Navigation
• Multi-Contour Seat
• Heated Front Seats
• 19-inch alloy wheels with 255 / 50 tires