RV Doctor: Wiping tranny fluid on tires. Good or bad idea?

Dear RV Doctor,
I recently read an article you wrote regarding tire damage by ultraviolet rays; it was very informative. I was talking to another RVer recently who told me that wiping the sidewalls with transmission fluid will help prevent sidewall cracks due to ultraviolet rays. My question to you is can this be possible? He claims that the properties of transmission fluid and the tires are very similar and that’s why it works. I would appreciate your comments on this since I just purchased six new tires for my rig after the originals were so cracked that I felt it would be dangerous to drive on them. – Carlo Coppola

Dear Carlo,
Negative on the tranny fluid. This will cause the tires to dry out excessively. As the oil evaporates it will deplete all the natural surface waxes blended in during manufacture. Avoid any product that contains petroleum-based or silicone substances. There are some nice products available in the aftermarket that can block UV rays and protect against ozone damage, but they typically will leave the tires with a dull sheen rather than the nice shiny surface most people like; plus they are probably less expensive. Cover the tires when not in use. The flexing and bending they receive while driving will bring the waxes back to the surface.

Gary Bunzer, The RV Doctor is the author of technical articles, troubleshooting tips, installation guides and owner’s manuals for RV owners, suppliers and manufacturers. He is the host of RV Roadtrips, the DIY Network cable television show. He is one of the RV industry’s most sought after speakers and the host of the popular DVD, Do It Yourself RV Care.