Mental Floss

Frost on Your Car’s Windshield? An Onion or Potato Can Prevent It

You might have everything you need for this winter car hack already—and right in your kitchen.
ByJake Rossen|
If only they had an onion or a potato.
If only they had an onion or a potato. | Santiago Urquijo, Moment Collection, Getty Images

Advocates for safe winter driving will tell you that being able to see out of your car’s windshield is a high priority before getting behind the wheel. In snowy climates, that can be a little bit of a problem thanks to frost build-up. While a defroster or ice scraper can restore visibility, they can add a few minutes to your commute.

You can, however, take a preventive measure with something you probably have right in your kitchen: an onion.

According to Today, you can cut an onion in half and rub it over your windshield to prevent frost. The onion will leave behind an invisible residue. When water or snow comes in contact with the glass, it will have a harder time forming solid ice.

The same principle applies to wiping your car down with a potato, though you may want to wait until your neighbors are back inside before doing this.

While this is most likely safe on your car’s windshield, you might want to try it on a small test spot first. And take caution when trying other prophylactic measures, like road salt or vinegar: Those can be corrosive and damage the glass, the car’s finish, or both. Warm or boiling water is even worse. You’ll be able to see out of the windshield, but only because it’s shattered.

Read More Stories About Cars:

A version of this story was originally published in 2022 and has been updated for 2025.

Home/LIVE SMARTER