Should You Idle Your Car on Cold Winter Mornings?

When it's cold and you have somewhere to go, should you let your car idle before you drive? You've probably been told it's good for the engine, but does it actually help?

You may recall chilly days when one of your parents went out to start the car long before anyone was ready to leave. By the time everyone was bundled up in their hats, boots, mittens, and scarves, the car was warm and ready to go.

We all want to take care of our vehicles because they’re an investment. We depend on them to get us where we need to be, and a breakdown or car repair is never convenient. But were our parents doing more harm than good by letting the engine idle? That depends.

Older Cars vs. Newer Cars

Cars made before the 1990s used carburetors, which required a few minutes of idling to warm up the engine and ensure the right air-fuel mix. In those vehicles, warming up the engine before driving was both necessary and beneficial.

However, cars built since the 1990s use electronic fuel injection systems that automatically adjust to temperature changes, ensuring the engine gets the right air-fuel mixture. For these vehicles, idling is no longer necessary and, in fact, is discouraged.

The Downsides of Idling

According to the Environmental Protection Agency (EPA) and the Department of Energy (DOE), a car’s engine warms up faster while driving than it does while idling. Idling wastes fuel, produces unnecessary pollutants, and causes additional wear on the engine. Mechanics warn that letting the engine idle for too long strips oil away from the cylinders and pistons, which can decrease the engine’s lifespan. Other risks of idling include exposure to carbon monoxide and the potential for vehicle theft if left unattended.

What You Should Do

While it’s true that fuel economy decreases in cold weather, there’s no need to warm up your car before driving. Simply start the engine and, if you need to, let it idle briefly to clear the windshield. Then, drive gently for the first few minutes to allow the engine to warm up naturally.

Warm wishes and safe travels from Acuity!