The 2018 GMC Canyon is available as a 4-door, 2-seat regular side. Starting at $21,100, the 2018 GMC Canyon SL 4x2 Extended Cab is powered by a 2.5L , 4 -cylinder engine mated to a manual transmission that returns an EPA estimated 20-mpg in the city and 26-mpg on the highway. The top of the line 2018GMCCanyonAll Terrain w/Leather 4x4 Crew Cab Long Box , priced at $ 38,700 , is powered by a 3.6L , 6 - cylinder engine mated to an automatic transmission that returns an EPA estimated 17-mpg in the city and 24-mpg on the highway.