Add Yahoo as a preferred source to see more of our stories on Google. What experts say about the health risks of idling in your car — and what you can do to make a difference. (Getty Images) ...

A car engine can use as much as half a gallon of fuel after idling for an hour. Why is 'idling' so bad for cars? What to know ...

You might be relying heavily on your engine hours and overall mileage to determine when to perform maintenance, but you should pay attention to idle hours, too.

Your engine feels calm at a stoplight because a hidden idle system keeps fuel, air, and spark in balance. That quiet stability is not luck, it is the result of sensors, valves, and software working ...