R-Class passenger protection includes a rigid, highly reinforced central cell with engineered crash structures, three-point seatbelts with pretensioners/force-limiters, dual-stage front airbags, front-side bags, full-length side curtains, rollover sensors and a tire pressure monitoring system. ESP stability/traction control, AWD, and ABS discs with Brake Assist and Electronic Brake force Distribution are also standard, and rear side airbags are optional.
Two distinct engine families provide motivation. The R350 has M-B's new 3.5-liter DOHC modular V-6 that's now filtering into other model lines. Producing 268 hp at 6,000 rpm, it uses variable valve timing to help turn out a stout 258 lb-ft of peak torque from 2,400-5,000 revs -- 90 percent of that from just over 1,500 rpm. The SOHC V-8 in the R500 is Mercedes' veteran 5.0-liter that develops 302 hp and 339 lb-ft of twist from 2,700-4,750 rpm. Both are backed by a slick seven-speed automatic transmission that's electronically activated by a column-mounted mini-shift lever and offers TouchShift gear changes via buttons on the steering wheel. The full-time, all-wheel-drive system has three open differentials but no low range. It integrates ESP stability and traction control, and can shift power to any corner to keep the R-Class going even if only one wheel has grip. Expect a full-on AMG R-Class and possibly a diesel variant in a year or so.
However you categorize it, the new R-Class is a quiet, refined transport module with an impressive dynamic envelope. Even the V-6 provides respectable acceleration and passing power--although with a curb weight between 4,700-4,900 pounds, the V-8 is an attractive alternative, dropping 0-60-mph times from just over eight to just under seven seconds and making hilly terrain and heavy passenger loads less challenging. Coming to grips with the mini shifter entails a sharp but short learning curve, however, the seven-speed automatic performs well enough in "D" that most owners will likely forego do-it-yourself shifting exercises.
The fully independent suspension, with or without the optional Airmatic assist and multi-mode Adaptive Damping System, is equally competent. Despite a 40.7-ft turning circle and tires that favor comfort over absolute grip, the R-Class maneuvers well and feels exceptionally positive and self-assured through corners. When you do start pressing it to the limit, ESP, AWD, and a multi-faceted and quite capable ABS system step up as needed to help maintain that confident character.
If there is a caveat of note, it relates to the long, conventionally hinged rear doors. They simply don't provide the same ease of entry/exit as the sliding units on most minivans do when you're trying to load people or transfer child seats in a crowded parking lot.