OPEN DIFFERENTIAL

While cornering,the outside wheels cut a wider arc than the inside. The differential needs to ensure that the outside and inside wheels are allowed to turn at different speeds-hence the name-while still supplying power to both wheels. The basic differential housing contains a large ring gear that meshes with a small pinion gear driven by the driveshaft. The ratio between the ring and pinion gear is known as the final-drive ratio or rear-axle ratio. The ring gear also spins a carrier containing perpendicularly meshing spider gears that allow the left and right axle shafts to spin

Independently. Downside: the wheel with the least traction limits power applied to the road.