Fun Factoid

A Guide to Defogging Your Windshield
Visibility is crucial when you're sitting behind the wheel, and nothing blinds drivers like a bad case of windshield fog. Of course, that cloudy film on your vehicle's glass is not fog at all–it's actually condensation. Here's how it works: your automobile's glass is chilled as you drive, but your cabin is warmed by your body heat or your vehicle's heater. When these two different barometric pressures collide, moisture condenses on the surface of the glass.
There are a number of techniques for removing fog from your windshield. The classic fix is to roll your windows down. The fresh air will help evaporate the moisture and balance out the temperature difference between outside and inside your vehicle. An even more effective method is to turn on your front defrosters, along with your air conditioner. The AC will strip the moisture from the air and clear up your windshield.
You can even take preventative measures to stop fog before it has a chance to form. Here's an easy recipe for some home-brewed anti-fog juice: mix 2 ounces of white vinegar with a quart of warm water in a bowl. Dunk a lint-free towel into the concoction and apply it to your pre-cleaned windows. After it dries, it will block condensation from collecting on your glass. It even works great on bathroom mirrors and scuba masks.