Eli5 Why do cars move at all when in drive without the accelerator being used. I’m not talking cruise control.

Question

Eli5 Why do cars move at all when in drive without the accelerator being used. I’m not talking cruise control.

In: 42

Answer 1

The engine is always turning in a petrol/diesel car. If the clutch is engaged, i.e. the pedal is not pressed, then the engine is connected to the wheels and thus they will also turn. (If the wheels cannot turn due to a steep slope or something then the engine starts having problems and will very quickly stall).

Automatic cars have a slightly different clutch mechanism which others have already explained well but you can treat it as if the clutch is always engaged.

So in summary: the car moves because the engine has to keep turning to be on, even in an idle state with no acceleration, and the wheels are connected to the engine.