The 2023 BMW M8 is available as a 2-door, 4-seat coupe. Starting at $134,100, the 2023 BMW M8 Coupe is powered by a 4.4LL , 8 -cylinder engine mated to an automatic transmission that returns an EPA estimated 15-mpg in the city and 22-mpg on the highway. The top of the line 2023BMWM8Convertible , priced at $ 143,700 , is powered by a 4.4LL , 8 - cylinder engine mated to an automatic transmission that returns an EPA estimated 15-mpg in the city and 22-mpg on the highway.