Should you warm up your car in the freezing temps?
With the current cold snap Western Pennsylvania and much of the country is experiencing, some people are braving the cold to “warm up” their automobiles before heading out on their commute.
But is that really the best thing to do?
The consensus says that warming up your car is unnecessary and wasteful.
According to Firestone , warming up your car used to help when cars had carburetors, as the carburetor needed to be warm to get the right mixture of air and fuel for the engine to run correctly. But in the 1980s and 90s as fuel-injected engines became standard there wasn't a need to warm up the engine, as electronic sensors would determine the temperature and allow for the right mixture.
Firestone recommends getting in your car and driving.
Car Talk's Ray Magliozzi agrees. In an interview last year he said that while he's still a warm-up-the-car kind of guy, with modern car you don't have to do that. “So yeah, get in it, and drive it. And it'll warm it up faster because when the engine is doing the work of pushing the car.”
The EPA strongly states that idling causes pollution and wastes fuel, adding that there is no need to turn on the engine until you are ready to drive.
The agency also says the same goes for vehicles with diesel engines, like school buses : “School bus engines do not need to idle more than a few minutes to warm up. In fact, extended idling causes engine damage. Engine manufacturers generally recommend no more than three to five minutes of idling.”
In addition to being unneeded, some cities and states have restrictions against idling cars, buses and other vehicles. In Allegheny County the rule states buses should not idle for more than five minutes, unless the temperature gets below 40°F. Diesel exhaust can cause significant health risks for children and elderly.
So while it may seem like warming up your car is helping the engine, and getting into a warm and toasty car is more pleasant than sitting on a frozen seat, you can just turn on the car and go.