The 2010 Mercedes-Benz R-Class is available as a 4-door, 5-seat sport utility. Starting at $49,300, the 2010 Mercedes-Benz R-Class R 350 is powered by a 3.5L , 6 -cylinder engine mated to an automatic transmission that returns an EPA estimated 14-mpg in the city and 19-mpg on the highway. The top of the line 2010Mercedes-BenzR-ClassR 350 BlueTEC , priced at $ 50,800 , is powered by a 3.0L , 6 - cylinder engine mated to an automatic transmission that returns an EPA estimated 18-mpg in the city and 24-mpg on the highway.