The 2007 Mercedes-Benz SL-Class is available as a 2-door, 2-seat convertible. Starting at $128,800, the 2007 Mercedes-Benz SL-Class SL 55 AMG is powered by a 5.4L , 8 -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 2007Mercedes-BenzSL-ClassSL 65 AMG , priced at $ 186,000 , is powered by a 6.0L , 12 - cylinder engine mated to an automatic transmission that returns an EPA estimated 13-mpg in the city and 19-mpg on the highway.