The M-Class is available with four different powertrains. The ML350 offers a 268-horsepower, 3.5L V6, and is available with either 4-wheel drive or rear-wheel drive. The rest of the lineup is all-wheel drive only. The ML550 gets a 382-hp, 5.0L V8, while the high-performance ML63 AMG adds a 503-hp, 6.3L hand-built V8. Across the line power is sent out via a 7-speed automatic transmission.
There's also a diesel model; the 3.0L turbo-diesel V6 in the ML350 Bluetec makes 210 horsepower and 400 pound-feet of torque. It's rated at a frugal 18 mpg city, 24 highway. Thanks to an AdBlue exhaust treatment system, the diesel engine meets 50-state emissions rules and its generous torque rating makes it an ideal choice for towing.

With a 3.5L V6 engine plus twin electric motors, the ML450 Hybrid generates up to 275 hp and 258 pound-feet altogether. The full hybrid system is capable of using electric power only at low speeds, and the nickel-metal-hydride battery pack is mounted under the cargo floor. The Hybrid model includes a display indicating the power flow between the battery and gasoline engine.

The M-Class is primarily set up for on-road driving, but the full-time 4-wheel drive system employs open differentials and a 4-wheel traction control system can send power to just one corner when the rest of the wheels lose traction. During normal driving, the system distributes power 50/50 front to back. It also includes an Off-Road Mode, which engages a different anti-lock braking mode for loose surfaces, allows slightly more wheel slip, and makes the accelerator pedal less aggressive. The M-Class includes Downhill Speed Regulation and Hill-Start Assist to control speed on steep slopes.

On-road, the M-Class rides quite smoothly and handles reasonably well for such a tough vehicle, thanks to its 4-wheel independent suspension that includes a double wishbone front suspension and 4-link rear setup. A height-adjustable air suspension is standard on the ML63 AMG but optional on other models, while an Active Damping System allows four different setting from comfort to sport.

The M-Class is extremely well equipped for occupant protection, including front side airbags, head-protecting window curtain airbags for front and rear occupants, stability control, anti-lock brakes with Brake Assist and a rollover sensor system. Available feature include POST-SAFE, which automatically unlocks the doors and shuts off the engine and fuel system after an accident.

The M-Class is strictly a 5-passenger vehicle, but it has plenty of space for adults in back, along with adequate cargo space. All M-Class models include a long list of conveniences such as power seats, cruise control, dual heated mirrors, a sunroof and keyless entry, while ML550 models add heated seats, rain-sensor wipers, running boards, Burl Walnut trim, and upgraded brakes. The ML63 AMG brings even larger brakes, the Airmatic suspension, special Nappa leather and aerodynamic bodywork.

The options list is extensive on the M-Class, and includes Bi-Xenon curve-illuminating headlamps, Parktronic, a power liftgate, heated rear seats, a heated steering wheel, Bluetooth, Keyless Go, a rear-seat entertainment system and a harman/kardon Logic 7 premium audio system.

Ride Quality

Towing Ability

Moderate Off-road Ability

ML63 AMG Performance

Fuel-efficient Bluetec Model

Upcoming Hybrid Availability

For 2011, the Mercedes-Benz M-Class vehicles receive only minor changes. Exterior side mirrors have been redesigned, while rearview mirrors feature a compass, as well as available Blind Spot assist and integrated rear view camera. The ML63 AMG model features a new hood, as well as darkened Bi-Xenon headlights with active light function. Diamond White Metallic exterior paint is new as well.

The Mercedes-Benz M-Class is tough enough for light off-roading and has serious towing ability, yet it's spacious enough for four or five adults and has a smooth ride. With the ML350 Bluetec diesel and the ML450 Hybrid, the M-Class lineup is fuel-efficient without sacrificing performance or capability. But for those who want top performance, the ML63 AMG, with its 503-hp V8, remains the king of the lineup.