The 2018 Mercedes-Benz CLS 550 is available as a 4-door, 4-seat sedan. Starting at $75,150, the 2018 Mercedes-Benz CLS 550 CLS 550 Coupe RWD Sedan is powered by a 4.7L , 8 -cylinder engine mated to an automatic transmission that returns an EPA estimated 18-mpg in the city and 26-mpg on the highway. The top of the line 2018Mercedes-BenzCLS 550CLS 550 Coupe AWD 4MATIC , priced at $ 77,650 , is powered by a 4.7L , 8 - cylinder engine mated to an automatic transmission that returns an EPA estimated 17-mpg in the city and 25-mpg on the highway.