The 2021 BMW M3 is available as a 4-door, 5-seat sedan. Starting at $69,900, the 2021 BMW M3 Base (M6) is powered by a 3.0LL , 6 -cylinder engine mated to a manual transmission that returns an EPA estimated 16-mpg in the city and 23-mpg on the highway. The top of the line 2021BMWM3Competition (A8) , priced at $ 72,800 , is powered by a 3.0LL , 6 - cylinder engine mated to an automatic transmission that returns an EPA estimated 16-mpg in the city and 23-mpg on the highway.