The 2005 GMC Sierra 1500 is available as a 2-door, 3-seat regular side. Starting at $23,395, the 2005 GMC Sierra 1500 Work Truck 4x4 Regular Cab 6.5' Box is powered by a 4.8L, 8-cylinder engine mated to an automatic transmission that returns an EPA estimated 16-mpg in the city and 19-mpg on the highway. The top of the line 2005 GMC Sierra 1500 SLE Hybrid 4x4 Extended Cab 6.5' Box, priced at $32,040, is powered by a 5.3L, 8-cylinder engine mated to an automatic transmission that returns an EPA estimated 17-mpg in the city and 19-mpg on the highway.