Engine Braking

It reduces brake wear and heat on long descents. A lower gear gives stronger engine braking. Electric cars use regenerative braking for a similar effect. Modern fuel-injected engines cut fuel during engine braking, so lifting off in gear uses no fuel. Heavy vehicles add exhaust brakes or retarders.

The engine is driven by the wheels and its pumping and friction losses slow the car.

Use a lower gear on long downhill roads. Do not over-rev when downshifting.