The 2003 GMC Envoy is available as a 4-door, 5-seat sport utility. Starting at $30,895, the 2003 GMC Envoy SLE 4x4 is powered by a 4.2L , 6 -cylinder engine mated to an automatic transmission that returns an EPA estimated 15-mpg in the city and 21-mpg on the highway. The top of the line 2003GMCEnvoySLT 4x2 , priced at $ 33,495 , is powered by a 4.2L , 6 - cylinder engine mated to an automatic transmission that returns an EPA estimated 16-mpg in the city and 22-mpg on the highway.