Turning is essential to driving, and your differential is essential to turning. That’s why maintenance of this part of your vehicle is crucial. But what does a differential do anyway? Think about it like this: Because the wheels of a car spin at different speeds, and while turning, travel different distances, your car needs to compensate in order to make a turn. (The wheels on the inside of the turn have to spin slower and travel a shorter distance, while the wheels on the outside of the turn need to spin faster to travel a greater distance.) Your car’s differential is the device that directs power to the wheels and controls the speed of some or all of the wheels, enabling your car to turn without putting too much strain on its axles.