A carryover, the 2009 GMC Sierra 3500HD one-ton pickup truck is available in regular cab, extended cab and crew cab designs, and a choice of cargo bed lengths and wheelbases, as well as two- or four-wheel drive. The Sierra 3500HD is powered by a standard 6.0L V8 engine with 360 hp and 380 lb-ft of torque or a 6.6L turbo-diesel V8 with 365 hp and 660 lb-ft of torque, paired to a six-speed automatic, heavy-duty, electronically controlled transmission with overdrive and tow/haul mode. Depending on the trim level, the Sierra 3500HD can seat up to six passengers. GMC Sierra 3500HD standard features indicate a maximum towing capacity of 16,500 pounds when equipped with a fifth-wheel hitch. For safety, four-wheel antilock disc brakes; frontal, driver and right-front passenger airbags; and the OnStar communications system come standard on the Sierra 3500HD. EPA-estimated fuel economy figures are not available.