Algodoo

Hold s to start the starter motor, wait a second, then hold down enter to start the fuel supply, and then release s to complete starting. Releasing enter will stop the engine.

EDIT:
New version! The engine is pretty crazy now and while accelerating you may get blips with the car. When the speed gets to around 57m/s the enging may seem like it has stopped working, but it hasn't. The circles that get spawned are set at a velocity of 60m/s. This is so the don't go through the blades of the engine. Slowing down will cause the engine to start working again.

Have Phun!