When you downshift gears in a manual car, you’re essentially telling the engine to work harder. This increases the RPMs, which in turn makes the car go faster. Engine braking is when you use the engine to slow down the car, rather than using the brakes. This is done by shifting into a lower gear so that the engine has to work harder, which slows down the car. Some people believe that engine braking is better for your brakes because it doesn’t wear them out as much.