The 2008 GMC Yukon is available as a 4-door, 5-seat sport utility. Starting at $39,205, the 2008 GMC Yukon SLE w/3SA 4x4 is powered by a 5.3L , 8 -cylinder engine mated to an automatic transmission that returns an EPA estimated 14-mpg in the city and 19-mpg on the highway. The top of the line 2008GMCYukonCommercial Fleet 4x4 , priced at $ 39,205 , is powered by a 5.3L , 8 - cylinder engine mated to an automatic transmission that returns an EPA estimated 14-mpg in the city and 19-mpg on the highway.