As the weather gets colder across the U.S., more people are likely letting their car “warm up” for a few minutes before they get in and drive. It doesn’t make sense from a technological standpoint, and it may be illegal where you live.
The general rule – as has been true for years – is that there’s little real benefit to letting your car warm up before you start driving. We’ve been struggling to learn this lesson.
There was a time, when carburetors ruled the earth, that idling a cold car was a useful idea, but this is not true today. A modern car heats up in about 30 seconds once you start moving, making a five-minute warmup really just an exercise in wasting emissions.