The 2012 Mercedes R-Class is an unusual vehicle. It's definitely not a minivan nor is it really a crossover (even though that's what Mercedes-Benz calls it). Rather, the 2012 Mercedes-Benz R-Class has staked its territory as a no-nonsense rolling monument to practicality. With comfortable seating for six, standard all-wheel drive and the option of a diesel engine, the R-Class puts some of the best-selling SUVs on the road to shame. The R-Class suffers from puzzling nomenclature. The gasoline-fueled version is called the R350 4MATIC, while the diesel-burning variant is the R350 BlueTEC. Both have all-wheel drive.