Quote:
Originally Posted by MikeW
Engine braking is the act of using the retarding forces within an engine to slow a vehicle down, as opposed to using an external braking mechanism, e.g. friction brakes or magnetic brakes.
The term engine braking usually refers to the braking effect caused by throttle position induced vacuum in petrol engines. While some of the braking force is due to friction in the drive train, this is negligible compared to the effect from vacuum.
When the throttle is lifted less air is allowed to pass through the intake manifold, and the engine works against this vacuum. It is the deceleration of the engine against this vacuum which provides the braking effect.
As per Wikipedia  |
So is downshifting instead of letting the foot off the gas engine breaking?