If you’re going to be idling for more than 10 seconds, you can get 30 more miles per tank, according to the Canadian Office of Energy Efficiency and the Celias blog.
Idling uses up a lot of gas. You’ll save money, and the environment. The Swiss like this method and it’s the law in several of their cities to turn off your car at stoplights.
But what about the gas used to start a car? All cars use fuel injection, so starting a warm engine is negligible. And the cost of that or the wear on your starter is far outweighed by the fuel savings. — BEN POPKEN