The 2011 Mercedes-Benz SL-Class is available as a 2-door, 2-seat convertible. Starting at $198,750, the 2011 Mercedes-Benz SL-Class SL 65 AMG is powered by a 6.0L , 12 -cylinder engine mated to an automatic transmission that returns an EPA estimated 12-mpg in the city and 18-mpg on the highway. The top of the line 2011Mercedes-BenzSL-ClassSL 63 AMG , priced at $ 139,050 , is powered by a 6.2L , 8 - cylinder engine mated to an automatic transmission that returns an EPA estimated 12-mpg in the city and 19-mpg on the highway.