Windows open or closed, when parked on a steamy summer day? Tom and Ray settle a marital debate.

Dear Car Talk

Dear Car Talk | Jun 01, 2007

Dear Tom and Ray:

I have an ongoing "debate" with my hubby about whether or not to leave our car windows open slightly when it is really, really hot. One of us says we need to do this to keep the windows and windshield from cracking (especially if there is a drastic temperature change due, for example, to a thunderstorm). The other doesn't think it's necessary and prefers to leave them closed (especially to keep from having to dash outside to close them in case of the aforementioned storm!). So, oh Automotive Gurus, which do you recommend -- open or closed? Thanks! -- Barbara

TOM: It depends on who has to do the dashing, Barbara.

RAY: Actually, there's no need to keep the windows ajar. The windows and windshield will not crack from the heat, nor from the sudden drop in temperature that often accompanies a thunderstorm. After all, if that were the case, your windows would crack every time you got into a hot car and cranked up the air conditioning, right?

TOM: So, if you don't mind getting into a hot car, you are free to leave all the windows closed.

RAY: If the heat is an issue for you, though, you have several options. One is to just open the windows a tiny bit -- not enough to let any significant rain in, but enough to allow some hot air to escape. And just to be on the safe side, in case it does rain, open the window next to where your hubby sits (or leave the back windows cracked open, where no one sits).

TOM: If heat and thunderstorms are regular problems where you live, you can even buy some snap-on rain guards (sometimes called "vent visors"), which cover the top of the window. They angle out from the top of the door, deflect the rain and allow you to leave the window open an inch or so without any water coming in.

RAY: Finally, we will recommend an old and sadly neglected remedy for extremely hot weather: Park in the shade. Try it. You'll be amazed what a difference it makes!

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