The 2013 Mercedes-Benz GL-Class is available as a 4-door, 7-seat sport utility. Starting at $63,900, the 2013 Mercedes-Benz GL-Class GL 450 is powered by a 4.7L , 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 2013Mercedes-BenzGL-ClassGL 63 AMG , priced at $ 116,925 , is powered by a 5.5L , 8 - cylinder engine mated to an automatic transmission that returns an EPA estimated 13-mpg in the city and 17-mpg on the highway.