An idling car gets zero miles per gallon, but still produces toxic emissions.
Everybody knows if you turn off a light bulb as you leave the room you'll save electricity. If you turn off your car you’ll save gas. In fact, idling for 15 minutes burns through an average of a quarter of a gallon. If you’re at a railroad crossing, at a long traffic light, sitting in the drive-through lane, or even waiting to pick someone up, turn off your engine. It's as simple as that.