Myths and Facts

You’ve probably heard that idling is a good way to warm up your engine. Or maybe you were told that letting your car idle consumes less fuel than turning it off and starting it up again. However, you’ve been hearing wrong – modern engines never “need” to idle. Check out these idling myths and facts, courtesy of modern science.

Myth 1: Idling is good for your engine

FACT: Too much idling can actually damage your vehicle. Engines don’t operate at peak temperature when they’re idling, so fuel is only partially burned. This leads to fuel residue buildup, which hurts engine parts and reduces gas mileage.

Myth 2: Restarting a car uses more fuel than letting it idle

FACT: Engines don’t work efficiently when they’re idling. Experts say that after idling more than 10 seconds, cars waste fuel. Today’s engines are designed to get more miles to the gallon. But when you’re idling, you’re getting zero, and your engine’s not working to efficiency specifications.

Myth 3: Letting a car idle on a cold day is a good way to warm it up

FACT: The best way to warm up a vehicle is to drive it. Even modern diesel engines don’t need more than a few minutes to warm up in cold weather.

Myth 4: Idling doesn’t waste much fuel

FACT: Idling for an hour can waste half a gallon or more of fuel. Wouldn’t you rather use that gas to get somewhere?

Myth 5: Restarting is hard on your engine

FACT: Restarting your engine puts no more stress on it than any other normal use. But idling forces it to run inefficiently, reducing engine performance and fuel efficiency over time.