- $32 for a conventional oil change with tire rotation and Rain-X treatment (a $65 value)
Rain-X: Putting Drivers in the Clear
Rain-X doesn’t just make your car look better—it also makes you safer. Find out how with Groupon’s exploration of this water-repelling substance.
When rain beats down on a windshield, it can react one of two ways. It can splash indiscriminately across the glass, causing light to scatter and cloud the driver's visibility. Or, if the glass is treated with a hydrophobic solution such as Rain-X, the random splashes can turn into cohesive beads that trickle quickly off the windshield and out of sight. This process seems straightforward, but the effects are actually quite dramatic—a 1997 study by the University of Michigan concluded that participants driving behind a hydrophobic-treated windshield had an increased reaction time averaging one additional second over drivers with untreated windshields.
Developed more than 40 years ago, the chemistry behind Rain-X draws largely on two familiar substances: ethanol and isopropanol, or rubbing alcohol. Several organic methyl and synthetic silicone molecule chains dissolve in the alcohols to sheath glass in a water-repellent layer. From the original windshield solution, Rain-X has expanded its water-beading technology into other products, including wiper blades and full-car waxes. Innovative users have called on Rain-X to repel moisture from the top sheets of skis to submarine antennae, an application discovered by Australia's Department of Defense.