Idling Your Car: A Bad and Expensive Old Habit


As everyone gets into the flow of the new school year, parents across the country are spending countless minutes in their cars, waiting for their kiddos and friends to make their way from classrooms to their rides. Over the course of a school year, how many hours do you think those minutes of car idling add up to? Quite a few, right? And probably one of the last things on everyone’s mind is questioning whether or not it’s a good thing to let your car idle while you’re waiting.

But, it’s not a bad thing to consider. Old advice warns us that restarting our cars uses a lot of gas or might be hard on our starters, so we should just leave cars running. However, what most people don’t know is that with electronic ignition, it only takes 10 seconds of idling time to equal the power of restarting your car. So if you’re idling your car for longer than 10 seconds, it makes economic sense to turn it off.

Is this mechanically sound advice? Most organizations advise somewhere between a 10 and 60 second rule. There is an added strain on your starter and battery, but that amounts to minimal cost, and some experts say that idling is much harder on your engine than restarting it. Either way, the cost of maintenance isn’t much compared to what you’d be saving in gas.

The average driver spends about 16 minutes a day idling. If you have a small 4-cylinder engine and can cut out only 5 minutes of idling per day, you will save about $30 per year. If your car has a larger engine or you can reduce your idling by more — say, 10 minutes per day — you could save up to $200 per year. Even in cold weather, most cars in most conditions don’t need more than 30 seconds of idling to warm up. After that, they warm up better while in motion (and it’s better for them). You just need to avoid accelerating quickly for the first few minutes.

Not only do you save money when you refuse to let your engine idle — you reduce your carbon footprint too. Nationwide, the U.S. wastes 3.8 million gallons of gas each day by idling. However, if we could stop idling altogether, not just for one day, but all year, that would be like taking over 2.6 million passenger cars off the road — that’s more than all the passenger vehicles in the state of Connecticut.

Are you in the habit of idling your car? Here are common places for idling:

  • Schools
  • Driveways
  • Drive-throughs
  • Car washes
  • Gas stations
  • Banks

A lot of idling also occurs in traffic, but it can be dangerous to turn off your engine in these instances, and it is illegal to do so in several states.

The bottom line? If you’re going to be idling for longer than 30 seconds, and you don’t need the heat or AC on to keep anyone from freezing or burning up, turn the car off. You’ll be saving money and the environment at the same time.