While the R-class will be built in Alabama, the B-class will roll off the same German assembly line as the A-class. At 168.1 inches long and 63 inches high, the five-door hatch belongs in the same size class as the European-market Volkswagen Touran, Renault Scnic, and Opel Zafira. But unlike these micro-minivans, which rarely show up without kiddie seats and a stroller in the trunk, this is more of a minivan for grown-ups. The B-class has too much back-seat space to waste it on toddlers. Rear legroom is truly generous, headroom abounds, and shoulder room is fine.
The sandwich-floor concept-whereby, in the event of an accident, the engine slides under the passengers into a space also occupied by the fuel tank-pays off because it is paired with a full-length, 109.5-inch wheelbase. As a result, the B feels notably bigger inside than its rivals. It also has a cavernous trunk that swallows between 18.5 and 58.3 cubic feet of luggage, depending on whether the second-row seats are up or down.
The nineteen-inch wheels and liquid steel paint job won't make it into production, but this clever package is compact and versatile, luxurious yet totally sensible. As with the A-class, the rear seats can be folded or removed easily. The one ingredient the B-class lacks is all-wheel drive (it's front-wheel-drive only).
The B-class makes do with four-cylinder engines, topped by a 187-hp, 2.0-liter turbo. The show car is fitted with the top-of-the-line 2.0-liter diesel. Complete with a particulate filter, it musters 138 hp and 221 lb-ft of torque at a lowly 1600 rpm. Mated to the continuously variable Autronic transmission, with a choice of seven stepped gear ratios, the sixteen-valve diesel re-turns an average of 47 mpg. Compared with the A-class, the longer and heavier B exhibits better straight-line stability, a more supple ride, and better roadholding.
The plan is to build 100,000 B-classes and 50,000 R-classes a year. The B will be the smallest Mercedes offered in the States, and it is unlikely to sell in high volumes, whereas it looks to be a smash hit in Europe. Mercedes is betting that the R-class will find most of its takers here, despite the less-than-stellar success of the essentially similar Chrysler Pacifica. Prices are expected to start in the mid-$50,000s range. The B-class is likely to undercut the C-class, starting in the mid-to-high-$20,000s.