Powertrain

In a motor vehicle, the powertrain or powerplant comprises the main components that generate power and deliver that power to the road surface, water, or air. This includes the engine, transmission, drive shafts, differentials, and the final drive (drive wheels, continuous track (as in military tanks or caterpillar tractors), propeller, etc.). Hybrid powertrains also include one or more electric traction motors that operate to drive the vehicle wheels. All-electric vehicles ("electric cars") eliminate the engine altogether, relying solely on electric motors for propulsion.

A motor vehicle's driveline or drivetrain consists of the parts of the powertrain excluding the engine. It is the portion of a vehicle, after the prime mover, that changes depending on whether a vehicle is front-wheel, rear-wheel, or four-wheel drive, or less-common six-wheel or eight-wheel drive.

In a wider sense, the powertrain includes all of the components used to transform stored (chemical, solar, nuclear, kinetic, potential, etc.) energy into kinetic energy for propulsion purposes. This includes the utilization of multiple power-sources and non–wheel-based vehicles.