The Sierra 1500 Hybrid brings together the refinement, innovation, and capability you expect from GMC. Available in two- or four-wheel drive Crew Cab Short Box models, Sierra Hybrid provides the power and capability you expect from a utility vehicle while delivering efficiency you never imagined. Sierra Hybrid offers a two-mode hybrid propulsion system. This patented hybrid technology optimizes fuel economy for various driving conditions. A sophisticated control module helps determine the amount of power or torque that's required at a given moment and seamlessly selects the appropriate operating mode. First Mode is used at low speed and with light loads. The vehicle operates in 3-ways; electric power only, engine power only or a combination of both. The Second Mode is used primarily at highway speeds and includes Active Fuel Management. Innovations like Active Fuel Management and improved aerodynamics help Sierra get 332 horsepower and 367 lb.-ft. of torque.