The ML350 carries a 232-hp, 3.7-liter V-6 engine, while the ML500 comes with a 288-hp, 5.0-liter V-8. Both models use a five-speed-automatic transmission with a manual shift gate. The permanently engaged four-wheel-drive system has a Low-range gear setting, and it distributes power among the four wheels as needed to maintain traction. Unlike its X5 and RX 330 rivals, Mercedes insists that the M-Class is a true offroad vehicle.