The final drive is the last part of a set of gears that delivers the necessary torque to turn the wheels of a vehicle. It connects to the differential axle which connects to the wheels.
The requirement for a transmission system depends on the characteristics of an automobile's engine. Engines typically operate over a range of 600 to about 7,000 revolutions per minute, while the car's wheels rotate between 0 rpm and 1,800 rpm. A car requires a system that transforms the engine's output so that it can supply high torque at low speeds, but also operate at highway speeds with the motor still operating within its limits.