The 2021 GMC Yukon XL is available as a 4-door, 7-seat sport utility. Starting at $53,700, the 2021 GMC Yukon XL SLE 4x2 is powered by a 5.3LL , 8 -cylinder engine mated to an automatic transmission that returns an EPA estimated 16-mpg in the city and 20-mpg on the highway. The top of the line 2021GMCYukon XLDenali 4x4 , priced at $ 74,300 , is powered by a 6.2LL , 8 - cylinder engine mated to an automatic transmission that returns an EPA estimated 14-mpg in the city and 19-mpg on the highway.