The 2009 GMC Envoy is a 4-door, 5-seat Sport Utility, available in 6 trims, ranging from the Denali 4x2 to the SLT 4x4. Upon introduction, the $36,535 Denali 4x2 is equipped with a standard 5.3L, 8-cylinder, engine that achieves 15-mpg in the city and 21-mpg on the highway. an Automatic transmission is standard. The $35,615 SLT 4x4 is equipped with a standard 4.2L, 6-cylinder, engine that achieves 14-mpg in the city and 20-mpg on the highway. an Automatic transmission is standard.