The all-wheel-drive system has front, center, and rear open differentials, giving a 50/50 percent torque split. The front suspension has upper and lower control arms, while the rear end has a four-link arrangement. Height- adjustable Airmatic suspension is an option, mated to adaptive damping.
Power-assisted rack-and-pinion steering is standard on the R350, with a speed-sensitive arrangement on the R500. The R350 has ventilated front and solid rear disc brakes, while the R500 gets larger front rotors and ventilated discs at the rear. The optional AMG Sport package includes the aforementioned nineteen-inch wheels as well as different bumpers, side cladding, and four-piston brake calipers at both the front and the rear.
We drove an R500 and can safely say that it feels like an overgrown M-class. In the past, that would have been damning it with very faint praise, but the new M-class actually drives nicely, for a tall SUV. The R500 drives very well, too, for a supersized minivan.The familiar V-8 engine sounds sweet, particularly under full-throttle acceleration, and it endows the R500 with brisk, rather than startling, acceleration. It doesn't feel as quick off the line as Mercedes claims, but it has excellent midrange passing performance, helped by the closely stacked gear ratios. The seven-speed automatic is as slick as a corporate attorney, although the manual shift buttons aren't that easy to use.
As in the E-class, the Airmatic suspension is never quite perfect. We tended to leave it in the comfort-oriented setting, as that gives the smoothest, plushest ride. When you set the suspension in its firmest mode, the ride becomes quite harsh over expansion joints. If you fancy fast driving, you'll find the handling quite surprising for such a big vehicle. The steering is well weighted and full of feel at high speed but suffers a dead spot in low-speed running. The body control in sport mode is sensational compared with an Escalade, but the R-class is just too big, too heavy, and too tall to challenge a luxury sedan. The brakes were very impressive, as were overall grip levels.
The R500 is a really fine vehicle-fast, luxurious, and good-looking-but who's going to buy it? Mercedes says that its target audiences are "Late-Forming Affluent Families" and "Socialite Empty Nesters." Strip away the marketing speak, and that means successful professional couples who start procreating late in life and want to turn up at soccer matches with a flashy vehicle; and older, successful people who like going out with their friends. Call it a minivan for snobs, if you like.
This particular crossover makes a lot of sense for a lot of people, although Mercedes' projection of 30,000 sales a year seems very optimistic. After all, a base R350 will cost just under $50,000, and a fully loaded R500 will be close to $70,000.
We also wonder if M-B's current fascination with niche marketing isn't going to cut into its own sales. While the so-called luxury-sports-tourer market is set to expand in the future, we can't help but think that the R350 and the R500 will take sales from the E-class sedan and wagon, the M-class, the forthcoming G-class SUV, and the S-class as much as they will wean people away from luxury minivans and full-size luxury SUVs.