All five models are equipped with an automatic transmission and electronically managed 4MATIC all-wheel drive. The gasoline version of the ML350 is also available with rear-wheel drive. The ML350 BlueTEC is powered by a 3.0-liter turbo-diesel V6 generating 210 horsepower. The ML350 is powered by Mercedes' latest-generation 3.5-liter gasoline V6, generating 268 horsepower. The ML550 includes a 5.5-liter, 382-hp V8 and the top of the line ML63 AMG uses a 6.3-liter, 503-hp V8. All non-hybrid models receive a seven-speed automatic transmission. The ML450 is an advanced 2-mode hybrid which uses an eight-speed continuously variable transmission, a 275-hp V6 engine, and a 288-volt nickel-metal hydride (NiMH) battery for a combined rating of 335-hp. The ML450 Hybrid is able to accelerate using only the electric motor. The extensively equipped M-Class includes standard features such as stability control and active front head restraints, as well as front, side, and side curtain airbags.For 2011 the M-Class is a carryover from 2010.