The first M-Class combined trucklike construction -- a body on a ladder-type frame -- with that sophisticated suspension. But later competitors, including the Lexus RX300, took things a step further, retaining the independent suspension but using a one-piece unibody that further improved ride and handling. The new M-Class makes this leap, too, with a rigid unibody nearly 6 inches longer and 3 inches wider; the wheelbase was stretched almost 4 inches. The old M-Class, with its upright design and unsexy tailgate, looked like a minivan from some angles. Thankfully, the new design is sleeker and a bit aggressive, with a wedge shape more in tune with the styling of Mercedes-Benz sedans and coupes. I tested the six-cylinder ML350, and also drove the ML500 with a V-8 engine. In each case, the unibody construction made the M-Class feel wonderfully solid, with none of the quivers and shakes that often afflict body-on-frame trucks. With the redesigned independent suspensions, handling is agile for a vehicle so large and heavy. While the body leans if you force it hard into a turn, the motions remain well controlled, giving the driver a sense of calm and confidence.

The first M-Class combined trucklike construction -- a body on a ladder-type frame -- with that sophisticated suspension. But later competitors, including the Lexus RX300, took things a step further, retaining the independent suspension but using a one-piece unibody that further improved ride and handling. The new M-Class makes this leap, too, with a rigid unibody nearly 6 inches longer and 3 inches wider; the wheelbase was stretched almost 4 inches. The old M-Class, with its upright design and unsexy tailgate, looked like a minivan from some angles. Thankfully, the new design is sleeker and a bit aggressive, with a wedge shape more in tune with the styling of Mercedes-Benz sedans and coupes. I tested the six-cylinder ML350, and also drove the ML500 with a V-8 engine. In each case, the unibody construction made the M-Class feel wonderfully solid, with none of the quivers and shakes that often afflict body-on-frame trucks. With the redesigned independent suspensions, handling is agile for a vehicle so large and heavy. While the body leans if you force it hard into a turn, the motions remain well controlled, giving the driver a sense of calm and confidence.

The steering had a pleasing, consistent weight, though enthusiasts might complain that it lacks "feel" -- a quality difficult to define, but something that sporting drivers miss in its absence. The ride is comforting, though on rough roads passengers still feel the bumps. While the brakes performed well, the pedal wasn't as crisply responsive as I'd have liked. While the new M-Class plays catch-up in a crowded field, its seven-speed transmission sets a benchmark. Even with the V-6 engine it is almost like having a continuously variable transmission; one gear moves seamlessly to the next. The new V-6, which displaces 3.5 liters and is rated at 268 horsepower, pulls strongly. All 258 pound-feet of torque is available from just 2,400 r.p.m. 5,000 r.p.m. Acceleration is stronger, as you'd expect, but highway fuel economy is nearly as good as that of the V-6: 20 m.p.g. ML350 and 19 for the ML500. Indeed, the additional sixth and seventh gears improved highway mileage by 10 pecent, Mercedes says. Prices, while steep, are on par with the competition. 49,000 with self-indulgent options like a DVD navigation system, satellite radio, DVD player, sunroof and upgraded interior trim. The interior is strikingly different from before.

Instead of a flat, straight dash in mediocre plastic, there is a modern design with round vents and nicer materials. Mercedes went to great lengths to atone for its cup holder sins, moving the shifter off the console to make room for two adjustable holders. One can handle a 44-ounce Big Gulp! The shifter is now a small stalk protruding from the steering column. To shift manually with the TouchShift function, you press buttons on the back of the wheel. The more stylish sloping roof has stolen some cargo room. With the second row of seats up, there is 3.3 cubic feet less space; with the seats down, the deficit is 8.8 cubic feet. The second row is missing some nice features. The seatbacks don't recline, and they don't slide forward and back as the ones in the Lexus RX do. But the rear seat, a split bench, is now much easier to fold down.

The new M-Class carries only five people. If you want a third row, Mercedes will offer it in the new R-Class, a more conventional wagon. As always, Mercedes includes lots of safety features. Tire pressure monitors are new, and the side curtain bags have rollover sensors. A new feature lets the vehicle crawl down steep grades without driver interference, and an off-road mode lets the wheels spin a bit to gain traction in mud, gravel or slush. An air suspension is optional. While the vehicle doesn't have low-range gearing now, it will be included in an off-road package later. Most M-Class buyers won't care about that. They will appreciate the fact that this Mercedes provides the kind of carlike ride and handling Americans now demand in luxury S.U.V.'s, along with more style and the latest safety features. The new M-Class is not so indisputably fabulous that it destroys the competition, and past quality problems may be a cause for concern. Still, the redesign brings the M-Class up to date and makes it much more competitive in a very crowded field. INSIDE TRACK: Back in the hunt. We are continually improving the quality of our text archives.