Vortec 5.3L V8 SFI VVT Flex Fuel, 6-Speed Automatic, and 4WD. Won’t last long! Best color! You’ll be hard pressed to find a cleaner 2011 GMC Sierra 1500 than this gas-saving ride. Consumer Guide Recommended Large Pickup. Load this Sierra 1500 down with passengers, cargo, whatever! Its cavernous space will haul around everything you need. Home of the Lifetime Warranty!!