All over the United States, the polar vortex of 2019 forced schools and businesses to close. While the weather may have warmed up a bit, it’s still plenty cold. While you’re shut in, you may be wondering how often you should start your car to warm it up.

According to USA Today, the answer is never. And certainly not repeatedly.

Starting up your engine and letting your car idle for a while, probably won’t bring the car up to full operating temperature. Unless you drive your car around for some time, the car won’t really warm up enough to make a difference. Besides which, letting a car idle for a long time causes too much fuel to get inside your engine. Which is not good for your engine.

By the way, starting your car without actually driving it long enough to recharge the batter, will eventually lower your battery capacity.

Better than starting up your car whenever you think of it, focus instead on making sure you have decent antifreeze protection. Antifreeze is the ticket, because it will keep your coolant from freezing in subzero temperatures. And this is what you want to prevent. If your coolant freezes, it will expand, and the pressure of this expansion may crack your engine block.

Cars generally use a mix of half water/half antifreeze. That’s fine in cold weather. But in REALLY cold weather, you need more antifreeze, as much as 70 percent, according to Mike Calkins, cited in the U.S.A. Today article linked above. Calkins is manager of technical services at AAA, so it’s a pretty safe bet you can trust his advice. He suggests that if you don’t know how much antifreeze you’ve got in your mix, you should go find out, tout de suite.