Engine braking

Engine braking occurs when the retarding forces within an engine are used to slow a vehicle down, as opposed to using additional external braking mechanisms such as friction brakes or magnetic brakes.

The term is often confused with several other types of braking, most notably compression-release braking or "jake braking" which uses a different mechanism. The term only applies to petrol engines and other throttled engines (as opposed to diesel engines, electric motors, etc.)