Built for heavy-duty hauling, the 2015 GMC Sierra 3500HD’s tougher new look is available in a host of different configurations. Regular cab, double cab and crew cab versions of the 2015 GMC Sierra 3500HD pickup truck can be equipped with two-wheel drive or four-wheel drive. Trim levels choices for the 2015 GMC Sierra 3500HD consist of base, SLE, SLT and Denali. Built specifically for towing and hauling, two engines power the 2015 GMC Sierra 3500HD. A gasoline-powered 6-liter Vortec V-8 produces 380 pounds feet of torque and can run on E85 blended fuel. For mammoth torque production, the 2015 GMC Sierra 3500HD is also available with a 6.6 liter Duramax turbo-diesel powerplant. The Duramax turbo-diesel engine generates 397 horsepower and 765 pounds feet of torque for optimum work-duty performance. Conventional towing capacity for the 2015 GMC Sierra 3500HD is rated at 19,600 pounds while fifth wheel towing can reach 23,200 pounds. All models of the 2015 GMC Sierra 3500HD feature the added towing security of Stabilitrak with Trailer Sway Control. On the 2015 GMC Sierra 3500HD Denali model, standard features like enhanced IntelliLink infotainment system with Bluetooth connectivity, Bose audio system and leather seats provides executive style comfort to the pickup truck. SLT and Denali models of the 2015 GMC Sierra 3500HD also feature LED daytime running lights.