The 2021 BMW X3 is available as a 4-door, 5-seat sport utility. Starting at $45,000, the 2021 BMW X3 xDrive30i AWD is powered by a 2.0LL , 4 -cylinder engine mated to an automatic transmission that returns an EPA estimated 23-mpg in the city and 29-mpg on the highway. The top of the line 2021BMWX34x2 , priced at $ 43,000 , is powered by a 2.0LL , 4 - cylinder engine mated to an automatic transmission that returns an EPA estimated 25-mpg in the city and 29-mpg on the highway.