The phenomenon of using an internal combustion engine’s internal resistance to decelerate a vehicle is most pronounced when the engine operates at higher revolutions per minute (RPM) and the throttle is completely closed. This situation maximizes the vacuum created in the intake manifold, which resists the piston’s movement, thereby slowing the vehicle. A practical example would be downshifting to a lower gear while descending a steep hill; the increased engine speed and closed throttle leverage this retarding force significantly.
Effectively utilizing this deceleration method offers several advantages. It reduces wear and tear on the vehicle’s primary braking system, extending the lifespan of brake pads and rotors. Furthermore, it can provide a more controlled and stable deceleration, especially in adverse weather conditions where conventional braking might lead to skidding. Historically, understanding and employing this technique has been crucial for drivers of heavy vehicles, such as trucks and buses, to maintain safe speeds on long downhill stretches, preventing brake fade and potential accidents.
