It’s a freezing New England morning as your car is entirely covered in a layer of frost. Each day, as you get ready for school, you let the engine run while waiting for it to “warm up,” but how long should you actually let it idle before driving off each morning?
For years, drivers have believed that warming a car for a few minutes is needed for a smooth ride and to prevent engine damage. However, modern engines work differently than older ones, so warming them up for a long time might not be as helpful as some people think.
“Most modern engines don’t require long idling times,” says Mike Reynolds, a local mechanic. “They’re designed to warm up quickly once you start driving. In fact, idling for too long can be more harmful than helpful.”
The general recommendation from most car experts is to let modern cars idle for only about 30–60 seconds prior to driving. Fuel-injected engines function admirably, even when the outside temperature is exceedingly cold. Idling a car for an extended amount of time truly wastes a significant quantity of gas and causes a number of unneeded emissions.
“It’s a common misconception that cars need to idle for long periods,” says senior Tyler Brosch, who’s been driving for almost a year and is a car enthusiast. “I used to think five minutes was the minimum, but now I only wait a minute or two. It saves gas and time, too.”
There still are some valid reasons for letting any car run for a short time before anyone drives it. If your windshield is frosted over, you will always need more time to thoroughly defrost it. Many older vehicles could require greater time to warm up.
“Certain states actually make it illegal to idle [your car]. And there are whole countries where idling is illegal—if you go north to Canada, you can get a ticket just for sitting in a parking lot with your tailpipe running,” said Mr.Horsley.
Some drivers also warm up their cars simply for comfort. Nobody enjoys stepping into a freezing vehicle, and many people let the heater run for a couple of minutes before hitting the road. While this isn’t necessary for the engine, it’s a habit that many stick to during winter months.
“I don’t necessarily think my car needs it, but I let it warm up a little so my car isn’t freezing before I drive,” said senior Lucas Tinkham.
Ultimately, the best practice is to start the car, let it run for a short period, and then drive gently for the first few minutes. This allows the engine to warm up efficiently while avoiding unnecessary fuel waste. So next time it’s freezing outside, remember—your car might not need as long as you think to be road-ready.
