Quality Redemption

Mercedes-Benz is battling to retain its once-stellar quality image. The German auto maker's reputation has slipped; consumer complaints with some new models are stacking up.

The effort to halt the luxury brand's quality decline begins this spring, when Mercedes debuts the all-new '06 M-Class family of cross/utility vehicles.

The M-Class was one of the first players in the luxury SUV segment in 1998 and since then has received minor interior and exterior facelifts. This freshening, however, does little to protect M-Class market share from being eroded by more than 20 new competitors in the segment.

Most new entries take aim at the M-Class and some have succeeded in making the segment creator an also-ran in the sales race.

The new M-Class (classified as a CUV because of its unibody construction) breaks from its predecessor's traditional formula. Its new sheet metal measures 5.9 ins. (15 cm) longer, 2.8 ins. (7.1 cm) wider and 0.4 ins. (1 cm) lower than the previous model.

The '06 M-Class' exterior styling bears more than passing resemblance to the outgoing model, although it does take on a more athletic stance, with its overall wedge shape and bulging front and rear fenders. Some say Mercedes should have taken a more radical design approach when styling the new M-Class.

While the exterior may get mixed reviews, the interior moves M-Class to new heights. This is where the tangible results of the auto maker's aggressive quality push comes through. The feel of the materials is top-notch, and the old M's stodginess is gone. The extensive use of round accent areas, including the air vents and radio dials, is a welcome contrast from the flat, linear look of the previous interior.

Holger Hutzenlaub, who helped pen the CUV, says interior designers specifically wanted to add the different shapes to make the interior visually more appealing.

The center console benefits from a noticeable reduction in the number of buttons. Mercedes is following through on its promise to simplify accessory operation, while reducing the number of functions to those only that add value.

The previous-generation M-Class interior earned criticism for its sub-par, cheap-feeling materials. That's not the case with the new model, where the top of the instrument panel appears crafted from a single, high-quality piece; the new seamless passenger airbag adds to the clean look.

A cool new option for the '06 M-Class: a docking unit that enables iPod users to integrate their music selections directly into the vehicle's audio system.

The dock also charges the iPod, without draining the main vehicle battery.

A few noticeable and unacceptable omissions: Ventilated seats and an integrated DVD entertainment system for rear passengers are missing from the options list. Mercedes says it will offer both in the '07 model year.

Mercedes engineers decided on-road performance should trump off-road prowess, aware that less than 10% of previous M-Class owners were trail enthusiasts.

“We wanted to combine the comfort and driving dynamics of a sedan with the driving dynamics of a CUV,” says Thomas Weber, DC management board member responsible for research and development.

The M-Class rolls on an all-new unibody platform, which features high-stress points between the suspension and the body to handle the higher loads on the rare occasion when the vehicle traverses wild terrain.

The unibody structure improves torsional rigidity, helping reduce overall noise, vibration and harshness, say engineers.

During a test-drive through the city streets of Nice, France, down the highway to Provence, it is easy to see that the migration to the unibody structure was the proper developmental path.

The new M-Class is clearly superior to its predecessor in noise, vibration and harshness and ranks with the best vehicles in its class, nipping at the heels of the crushingly smooth Lexus RX 330. There are no squeaks or rattles, and wind and road noise is equally absent.

The impression of newfound refinement continues as the M-Class traverses the winding roads along the mountain ridges of the French Alps. The new independent front and rear suspension hugs the road, giving the M-Class a performance-oriented dynamic. The biggest change in the suspension is at the rear, which is mounted to a subframe that is isolated from the body by two solid rubber bushings and two fluid mounts that go the extra mile to damp vibration.

The new 4-link rear layout features forged-steel upper rods, sheet metal camber arms, cast-iron lower wishbones and tubular steel track rods.

The '06 M-Class also is the first CUV with a standard 7-speed automatic transmission. The use of the 7G-Tronic transmission provides excellent acceleration in any driving condition, while improving overall fuel economy. The transmission features shift-by-wire technology that enables more precise ratio engagement, with the ability to skip as many as three gears during a downshift.

M-Class owners have two engine choices at the outset: a 3.5L DOHC V-6 or optional 5L SOHC V-8.

The base 3.5L produces 268 hp at 6,000 rpm and 258 lb.-ft. (350 Nm) of torque between 2,400 and 5,000 rpm. Mercedes engineers decided to throw out the old SOHC, 3-valve-per-cylinder V-6 in favor of the new DOHC architecture, which in addition to numerous other advantages, enables the adoption of variable valve timing for intake and exhaust camshafts.

Those seeking more power will opt for the V-8, which develops 302 hp at 5,600 rpm and 339 lb.-ft. (460 Nm) of torque between 2,700 and 4,750 rpm. The V-8 continues with the older SOHC/3-valve modular V-6/V-8 architecture that eventually will be supplanted by the new DOHC/4-valve layout used by the M-Class V-6.

While the base engine is adequate for everyday driving, it's the optional V-8 that brings out the true character of the M-Class and showcases just how right the engineers were to emphasize on-road agility. The V-8 packs a noticeable punch, and the 7-speed transmission works in perfect harmony.

While Mercedes has been on the ropes for its lackluster quality, the new M-Class is proof the auto maker can right its course.

The '06 M-Class arrives in the U.S. in early April, with pricing estimated at less than $40,000 for the ML 350 and in the high $40,000-range for the ML 500.

'06 Mercedes ML350

Vehicle type: Front-engine, all-wheel drive, 5-passenger 4-door CUV

Engine: 3.5L (3,498 cc) DOHC V-6, aluminum block/aluminum heads

Power (SAE net): 268 hp @ 6,000 rpm

Torque: 258 lb.-ft. (350 Nm) @ 2,400-5,000 rpm

Compression ratio: 10.7:1

Bore × stroke (mm): 92.9 × 86

Transmission: 7-speed automatic

Wheelbase: 115 ins. (292 cm)

Overall length: 192.6 ins. (188 cm)

Overall width: 75.2 ins. (191 cm)

Overall height: 71.7 ins. (182 cm)

Curb weight: 4,541 lbs. (2,060 kg)

Competition: Acura MDX; BMW X5; Infiniti FX; Lexus RX330; Volkswagen Touareg