The 2020 BMW M8 Gran Coupe is available as a 4-door, 5-seat sedan. Starting at $130,000, the 2020 BMW M8 Gran Coupe Base is powered by a 4.4L , 8 -cylinder engine mated to an automatic transmission that returns an EPA estimated 15-mpg in the city and 21-mpg on the highway. The top of the line 2020BMWM8 Gran CoupeCompetition , priced at $ 143,000 , is powered by a 4.4L , 8 - cylinder engine mated to an automatic transmission that returns an EPA estimated 15-mpg in the city and 21-mpg on the highway.