2008 Mercedes-Benz M-Class Review

PROS
Fuel-efficient diesel engine, Great ride, Roomy and comfortable interior

CONS
Clunky transmission, Goofy COMMAND system for audio and navigation control, Limited rear visibility

Luxury SUVs are a dime a dozen. Nearly every high-zoot automaker has one, and some have several. Mercedes, for example, has three, the smallest of which is the ML-Class. ML was last redesigned in 2006, at which time it was joined by a chassis companion called the R-Class. The ML has seating for five passengers on two front buckets and a three-place rear bench while R-Class adds a third-row seat for seven-passenger capacity.

ML competitors include the Acura MDX, BMW X5, Cadillac SRX, Infiniti FX, Land Rover Range Rover, Lexus RX, Lincoln MKX, Porsche Cayenne, and Volvo XC90. Most are five-passenger crossover utility vehicles that marry a car-type chassis with a four-door wagon body style and a light-duty all-wheel drive system. A few competitors offer seating for seven and true off-road capabilities.
 
The ML comes in four distinct models, each identified by its unique engine. The ML350 comes with a 268-horsepower 3.5-liter V6, while the ML550 has a 382-horsepower V8. The ML320 comes with a 215-horsepower turbodiesel V6. Also available is the limited-edition ML63 AMG that comes with a hand-built 503-horsepower V8. All models use a seven-speed automatic that has steering-wheel-mounted buttons for manual operation of the transmission. Also standard is an all-wheel-drive system that does not have a low range and is not intended for severe off-road use.

Standard safety equipment on all models includes antilock brakes with brake assist, stability control, hill ascent and descent control, tire-pressure monitor, and dual-front, front- and rear-side, and curtain-side airbags. The curtain-side airbags have a sensor that triggers deployment in the event of a rollover. A front- and rear-obstacle-detection system is standard on ML63 AMG and optional on other models. Navigation-system-equipped models get a rear-view camera.

ML320/350 models come standard with dual-zone automatic climate control, tilt-telescope leather-wrapped steering wheel with radio controls, cruise control, vinyl upholstery, center console, split-folding rear seat, wood interior trim, power windows, power locks, power mirrors, keyless entry, sunroof, AM/FM/CD player with digital media player connection, automatic headlights, theft-deterrent system, and fog lights. ML550 adds heated front seats, roof rails, and running boards. The ML63 AMG adds uprated brakes, load-leveling suspension with active shock control, steering-linked HID headlamps, power tilt-telescope steering wheel, leather upholstery, ten-way power front seats with memory system, navigation system, rear-view camera, harman/kardon audio system, rear radio control, and satellite radio.

Most ML63 equipment is available as options on lesser models. Stand alone options include a rear-seat DVD-based entertainment system, iPod adaptor for the audio system, keyless starting, voice recognition, and adaptive cruise control.

The ML350 is the least expensive model at $44,000. ML320 CDI is just $1000 more at $45,000. ML550 lists for $52,750 and the ML63 AMG stickers for $87,000. All models have a destination charge of $825. The ML-Class is built in Mercedes-Benz' plant in Tuscaloosa, Alabama.

Get Up and Go
Mercedes-Benz quotes a 0-60 mph time for the ML320 CDI of eight seconds. That's on par with other V6-powered midsize SUVs and an impressive statement given the engine is a diesel. A little sluggish immediately off the line, the turbodiesel power builds quickly and passing response is impressive. Adding three more passengers doesn't seem to blunt acceleration as much as in some gas-powered competitors.

The diesel engine is rougher than similarly sized gas-powered engines both at idle, where there's some diesel clatter, and under hard acceleration. The diesel also has a narrower powerband, which leads to more shifting from the transmission.

That's a shame because the seven-speed automatic doesn't shift as smoothly as it should. Sometimes when accelerating, there a bang between gears that seems out of place in a luxury vehicle. Also, when decelerating, you can feel the transmission downshifting as it creates additional braking forces that make it difficult for drivers to come to a smooth stop.

The all-wheel-drive system works very effectively. There's absolutely no wheel spin on rain-soaked highways and little slip when on ice. Low range is not offered the ML. That's not unusual amongst luxury SUVs and fine if you don't plan on venturing far off the beaten path. Though the Mercedes' system has hill descent and ascent control and traction control, true off-roaders will want a low range for rock crawling.

The real advantage of the ML320 CDI is fuel efficiency. It is EPA rated at 18 mpg city and 24 mpg highway. Those numbers compare very favorably to smaller SUVs and even some crossover vehicles. Another bonus is the 500-plus mile cruising range. In real-world driving expect to average about 17 mpg in pure city driving. If your commute includes a fair amount of highway driving you might average as high as 26 mpg.

On the Road
With the available Airmatic suspension set to Comfort, ML320 sports a surprisingly refined--almost luxury-car like--ride. Most impressive is the way the suspension filters out minor road imperfections and expressway expansion joints. There is also little bobbing and bounding on rough roads. In the Sport mode the ride grows considerably busier but there are absolutely no secondary motions that are so common in larger SUVs. This setting gives the M-Class the taught ride control of a sport sedan without any undue harshness.

Predictably, handling limits are higher when the suspension is set in the firmer Sport mode, but the tires have plenty of grip regardless. When set to Comfort, there's enough body lean to warn enthusiastic drivers when to back off the throttle. The steering straddles a perfectly balanced line between road feel and assist. Unlike many other SUVs, there is no looseness or play at highway speeds.

The brakes have ample stopping power and the pedal is easy to modulate. Standard on all models is a hill descent control. It is designed to limit vehicle speed when descending steep grades by automatically engaging the brakes. Many SUVs have this feature, but it is uncommon among all-wheel-drive vehicles.

With wind, road, and engine noise well muted, the ML320 cruises serenely on the highway. Around town, the diesel engine clatters under hard acceleration. The extra noise is never offensive but it is noticeable. Sadly, the diesel does emit a bit of an odor that is most noticable when idling in confined spaces.

Behind the Wheel
In typical Mercedes-Benz fashion, the interior of the ML is understated and elegant. Most materials are appropriate for the class, but the door panel inserts have a budget look and feel. They wouldn't be out of place in a $40,000 SUV, but at nearly $60,000 the hard plastic panels seem cut rate.

Easy-to-read gauges face the driver from behind a large steering wheel that features redundant controls for the audio system and trip computer. The gear shift is mounted on a stalk to the left of the steering wheel. It's simple in operation: tap up for Reverse, down for Drive, and press in for Park. There are also paddles on the back of the steering wheel for manual operation of the transmission. This arrangement frees up space on the center console for cup holders and additional storage bins.

Window, lock, and mirror switches are conveniently located on the door armrest and illuminated at night. Audio and climate controls are placed high in the center stack. The climate control system features driver, passenger, and rear zones and a handy mode that uses residual engine heat keep the vehicle warm when the engine is shut off.

Either Mercedes' COMMAND system is becoming easier to use or I am just getting used to its Germanic silliness. Either way, it's still more complicated that simple buttons and knobs. For example, you have to reach way over to a joystick located on the passenger side of the center console to change the radio station. Also, you have to press tiny buttons at the side of the display screen to change between menu items. I suppose COMMAND is no less complex than other luxury automaker's vehicle control systems, but that doesn't make it good and doesn't mean that it makes sense for American buyers.

The ML has front seats that are firm and plenty supportive. Head and leg room are generous. Step in is slightly higher than the SUV norm, but not unacceptable. Outward visibility is good to all directions except dead astern, where the small rear window and thick pillars block the view. A back-up camera is available. It produces a well-illuminated image on the navigation screen and is mounted low to give good perspective.

Rear-seat passengers also get plenty of head and leg room. The seats are again firm and somewhat flat when compared to the fronts. There are rear-seat controls for the climate system and also headphone jacks with individual volume knobs for the audio system.

Cargo space is generous and has a built-in track with an adjustable divider that allows for easy and secure storage of smaller items. Rear seats fold, but not before flipping the seat cushions forward and making sure the front seats aren't all the way back. Once folded, the load floor is flat. Interior storage is highlighted by large door map pockets at all seating positions. Glove box and center console bins aren't as large as in some competitors.

Bottom Line
Though the current ML is more of a crossover SUV than its predecessor, it's still more truck-like in build than vehicles like the Acura MDX, BMW X5, and Volvo XC90. Positives include impeccable road manners, a roomy and comfortable interior, and plenty of convenience and safety features. In addition, Mercedes-Benz offers a model and engine for just about every buyer.

Prices start at a reasonable $44,000, but with options, it would be hard to find an ML350 at less than $50,000. The ML320 CDI is a very interesting proposition. It's only slightly more expensive than the 350, but gets considerably better fuel economy with only a slight penalty in smoothness and acceleration.