For 2007, Mercedes-Benz chose to upgrade its R-Class by adding a high-performance model, the R63 AMG, and a diesel version, the R320 CDI.
Introduced for the 2006 model year, the automaker says the R-Class "grand sports tourer" is the company's first model to blend the merits of a sport utility vehicle, sports sedan and luxury wagon. In addition to the new AMG and CDI versions, two more trim levels are available: the R350, equipped with a V-6 engine; and the R500, powered by a V-8. A seven-speed automatic transmission works with an all-wheel-drive system.
The R-Class evolved from the Grand Sports Tourer concept of 2000, and Mercedes said the production model didn't change much. Marketers promote the R-Class for its style, sophistication, luxury and spacious six-passenger capacity.
Front and rear design cues are modeled after Mercedes-Benz coupes and sedans. Rounded and squat at the rear, the new model flaunts a relatively long profile.
The unibody R-Class wagon is about an inch longer than Mercedes' flagship S-Class sedan. Two distinct sunroofs are optional: a conventional glass panel or a double-sized panoramic unit with a 5-foot-7-inch glass panel. When opening the panoramic sunroof, half of the panel moves atop the other so headroom isn't affected. Powered roller blinds in this roof protect occupants from the sun.
Privacy glass is standard, and a single-lift tailgate is installed. The R-Class' fully independent suspension uses double wishbones up front and a four-link setup at the rear. A load-leveling rear air suspension is standard, and the driver can select from three operating modes: Normal, Comfort or Sport. Dealer-installed roof rails are available.
The R-Class provides space for up to six occupants courtesy of three pairs of seats. Space between the first and second row measures 34 inches, with 30 inches between the second and third row. There's enough space between the second-row seats to walk through to the third row, and individual seats in both rear rows can be folded. An optional second-row console contains additional cupholders, and bottle holders are located in each door pocket. The seats have leather inserts, and brown bird's-eye maple wood trims the doors, dashboard and center console.
The four-spoke multifunction steering wheel features brushed-aluminum accents, and a new electronic gear selector is mounted on the steering column. The upper section of the two-tone dashboard arches over the instrument cluster, which holds two cylindrical binnacles for the speedometer and tachometer.
Weather-band reception is included in the standard radio, which has a single-CD slot and controls for optional satellite radio. An auxiliary plug in the glove box connects to MP3 players. Optional flat-screen monitors built into the back of the front head restraints can provide entertainment for rear passengers.
The R63 AMG makes the biggest splash in this department, pumping out 507 horsepower and 465 pounds-feet of torque. A 3.5-liter V-6 in the R350 develops 268 hp and 258 pounds-feet of torque. The R500's 5.0-liter V-8 produces 302 hp and 339 pounds-feet of torque. The R320 CDI will produce 221 hp and 398 pounds-feet of torque.
All the engines team with a seven-speed automatic. The transmission is able to skip as many as three gear ratios during downshifts to get the transmission in the proper gear. All-wheel drive includes three differentials.
Side curtain airbags protect occupants in all three rows of seats, and door-mounted side-impact airbags for front occupants are standard. A rollover sensor can activate seat belt pretensioners and the side curtain airbags. Antilock brakes and an Electronic Stability Program are standard, and a tire pressure monitoring system is installed.
The refined, versatile, luxurious R-Class yields a lush ride even when surfaces get rough. Few drivers could ask for a more satisfying luxury tourer for long hauls.
Handling is no less impressive. Steering feels just right for this new class of car, and it requires moderate effort with utterly satisfying response. The R500 stays on course through twisting roads without undue effort, and it behaves graciously with no unpleasant displays. Though not especially sporty in nature, it exudes luxurious confidence. Body roll occurs in curves, but it's not excessive and isn't too affected by the choice of suspension mode.
Acceleration with the V-8 is always abundant, with power that is refined, if short of startling. The automatic transmission functions effortlessly and always seems to know which gear to be in and for how long. The V-8 becomes taxed on steep grades, but downshifts are so smooth and appropriate that you hardly notice. The R350, with its V-6 engine, can scamper up grades almost as assertively, issuing only a little more engine noise.
Just a touch of driveline and road sound is evident, but the engine is nearly silent unless pushed hard. A nest of headrests impairs the rearward view, which is otherwise OK and helped by ample mirrors. The seats offer magisterial comfort and support, are wholly adjustable to suit one's physique, and remain appealing even after hours of driving. Reflections are evident in the steep windshield, but they're not too distracting. Cylindrical gauges are big and easy to read.