The 2017 Mercedes-Benz AMG GLS 63 is available as a 4-door, 7-seat sport utility. Starting at $124,100, the 2017 Mercedes-Benz AMG GLS 63 AMG GLS 63 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.