The 2021 Mercedes-Benz AMG GLS 63 is available as a 4-door, 7-seat sport utility. Starting at $132,100, the 2021 Mercedes-Benz AMG GLS 63 AMG GLS 63 is powered by a 4.0L, 8-cylinder engine mated to an automatic transmission that returns an EPA estimated 14-mpg in the city and 18-mpg on the highway.