Driving Impressions

With its bigger engine, the ML500 accelerates more quickly than last year's ML430: 0 to 60 in 7.7 seconds versus 8.0 seconds. This makes it one of the quickest SUVs on the market, as well as one of the thirstiest; the downside is fuel mileage, as the ML430 got 16 city and 20 highway, while the ML500 gets only 14/17. The front and rear axle ratios have been changed from 3.46 to 3.70, improving acceleration but reducing fuel mileage. So the ML320 and ML500 also get a bigger fuel tank, to 22 gallons from 18.5.

The flexibility of the 5.0-liter engine is impressive, with its broad torque range and whomping 325 foot-pounds. It works beautifully with the sophisticated five-speed automatic transmission. Floor the accelerator at any speed, and in a heartbeat the transmission downshifts and this 2.25-ton luxury truck gains speed, making quick, stress-free work of passing tractor trailers on two-lane roads; it downshifts so smoothly all you feel is a surge of power, as if a turbocharger were kicking in.

Even better, there's the joy of Touch Shift, which allows manual shifting by nudging the lever to the left or right, with the gear displayed on the instrument panel. There's a new transmission feature in 2002, called SOG, or Shift Optimized Gear function. As we understand it, SOG overrides Touch Shift when in the Touch Shift mode, reverting the transmission back to automatic if the driver's choice of gears doesn't please the program. We think an entire column might be written about this, which may or may not be funny. (It would only be funny to you, Sam. -ed.)

The front stabilizer bars have been made bigger on the 2002 M-Class, which features a double-wishbone, four-wheel independent suspension. Our ML500 provided a ride that was smooth, steady, firm and never jarring. The handling is extremely good for an SUV this heavy; it follows aggressive steering commands without fuss, and the beefy tires are grippy. A driver can feel the weight if he or she yanks the steering wheel, however, and it will lean some in emergency lane change maneuvers, but it's prone neither to pushing at the front end (understeer) nor sliding at the rear (oversteer). Of course, the magical Electronic Stability Program controls this loss of traction during cornering, particularly on dirt, gravel or slippery pavement. ESP applies brakes to individual wheels to help turn the vehicle evenly whenever it detects a skid. It too has been revised in 2002, to give a more rapid response.

The biggest problem with the handling might be the inconvenience of the heavy steering. At slower speeds the steering effort is very high, and women may not like this. You might even find yourself turning wider than you intended to, because you didn't muscle it enough. A weak-shouldered driver will have to watch it as they turn into a shopping-center parking space.

The anti-lock brakes, with massive discs, ventilated in front, are impressive, and the pedal feel is as solid as the rest of the truck. The ML500 slows quicker than almost any other SUV made.

The M-Class lacks a hand brake or locking differential, two pieces of hardware that experienced off-road drivers sometimes rely on. But with 8.7 inches of ground clearance, the M-Class is capable of traversing terrain that few SUV buyers are likely to challenge. A switch on the dash triggers low range for the full-time four-wheel-drive, allowing the vehicle to creep up and down seriously steep inclines. Meanwhile, the electronic power distribution delivers grip in mud, snow, or uneven ground. The electronics apply the brakes on wheels that are slipping, and then send most of the power to those that are gripping. The M-Class can creep forward even if only one wheel has a bit of traction.

The ML500 performs so well, its ride and handling so solid, that only the wealthiest, hard-core, high-performance buyers will feel a need for the image-heavy ML55 AMG. It can accelerate from a standstill to 60 mph in 6.4 seconds. That's q