It is More Efficient to Stop and Restart a Vehicle’s Engine than to Idle for as Little as Ten Seconds

Research from Argonne National Laboratory shows that stopping and restarting a vehicle for as little as ten seconds uses less fuel than idling the engine. Start-stop systems increasingly available on some cars and trucks automatically shut down the engine to save fuel. The fuel used when idling varies by the accessories used (radio, lights, and fans), vehicle make and model, ambient conditions, and many other factors.