Mercedes estimates that the gasoline model goes from 0 to 60 mph in 5.6 seconds and returns 13 mpg city and 18 mpg highway, versus an M元20 Bluetec's 8.0-second 0-to-60 and 18/24 mpg. Midrange acceleration was quicker in the gasoline model. The driving experience in the gasoline model was busier, and the power was more explosive and higher up than with Bluetec, which was more relaxed in nature, in some ways more refined. An '09 5.4-liter-V8 gasoline ML550 model makes more horsepower (382 at 6000 rpm) yet less torque (391 lb-ft at 2800 to 4800 rpm). Midrange acceleration is strong at 50 to 70 mph and 80 to 100 mph.įour-wheel-drive systems carry over, and the Bluetec powertrain qualities were the same for ML, GL or R-dip your toe into torque at any time. Full-throttle upshifts, also smooth, happen at 4000 rpm indicated if you're paddle-shifting, the tranny shifts itself before it lets you overrev. Power flows smoothly, effortlessly and quietly. The engine is rated at 210 hp at 3800 rpm, and with the tachometer dial marked in widely spaced 200-rpm increments, each marker carries big weight.Īccelerating hard from rest, there's instantaneous, locomotive-like push. These vehicles make big torque, 398 lb-ft holding between 16 rpm. Engineers paid particular attention to controlling high-pressure injection-system noise and isolating vibration with body and engine bearing mounts. When you push the M元20's start button, there's no shudder, vibration or clatter. The only 'diesel' clues are discreet Bluetec badges on front fenders and rear hatches. Mercedes is the first manufacturer to register 50-state diesel SUVs. The AdBlue tank is replenished as part of regular servicing. For '09, AdBlue-an aqueous urea solution in an onboard 28- to 32-liter tank-is injected into treated exhaust gas, which runs through a converter, reducing nitrous oxides into harmless nitrogen and water.

After sampling the latest Bluetec 320 ML, GL and R models, we're believers.Īll models share the 3.0-liter diesel and seven-speed automatic combination.

With Bluetec diesel variants of its luxury SUVs available, Mercedes-Benz says diesels are now environmentally as clean as gasoline engines, while providing the big torque Americans love, with greater fuel economy than comparable gasoline-fueled SUVs.

Mercedes ml320 bluetech