The 2011 GMC Sierra 3500HD is part of the truck's third generation, known for its rugged strength and durability. This full-size pickup truck offers 2WD and 4WD options and is available in three primary trims: Work Truck, SLE and SLT. The Sierra 3500HD offers a compelling lineup of engines including a standard 6.0-liter gasoline engine V8 that delivers 360 horsepower, and a 6.6-liter Duramax turbo diesel V8 offering impressive 397 horsepower. Transmission is handled by a 6-speed automatic. Safety features include standard antilock disc brakes, stability control, and front side and side curtain airbags. There's no shortage of tech here, with available satellite radio and OnStar telematics. For the 2011 model year, the Sierra 3500HD received a makeover, enhancing the truck's already formidable towing and hauling capacities.