Largely unchanged for 2009, the GMC Sierra 2500HD three-quarter-ton pickup truck offers a wide range of choices. In addition to two- or four-wheel drive, the selection includes three cab designs, three cargo box styles and five wheelbase lengths — plus Work Truck, SLE and SLT trim levels. The Sierra 2500HD is powered by a standard 6.0L V8 engine with 360 hp and 380 lb-ft of torque or the 6.6L turbo-diesel V8 engine, attached to a six-speed automatic, heavy-duty, electronically controlled transmission with overdrive and tow/haul mode. In addition, the Sierra 2500HD can seat up to six passengers, depending on the trim level. GMC Sierra 2500HD standard safety features include frontal, driver and right-front passenger airbags; four-wheel antilock disc brakes; and the OnStar communications system. EPA-estimated fuel economy figures are not available.