We once wrote about keeping your tires safe when stored in a hot, sunny climate. One of the points we made is this: “Old Sol can make a proper job of burning things up with UV rays. Outside, be sure to thoroughly cover your tires. Industry folk tell us that tires are best preserved when blocked from all light — so dark (black) covers that fully wrap around are best.”
One of our readers took a bit of exception to this advice. He writes, “I can’t agree with using anything black to cover the tires. Black absorbs sunlight and the extra heat is not what you want on the tires. Light transmission has nothing to do with the color of the material but the material itself.”
We asked industry expert Marvin Bozarth about how to best protect tires from UV light. Mr. Bozarth is the Tire Industry Association technical expert. Marvin noted that indeed, black actually absorbs UV radiation; therefore, UV rays will get through to a tire covered with a black cover, white or other colors, unless specially treated to block UV rays.
We then called on one of the top-selling RV tire cover manufacturers for their take on the situation. A representative from ADCO Products, a maker of tire covers sold by outfits like Camping World, told us that, yes, their tire covers are made with “automotive vinyl that’s pressed with a UV inhibitor.” When we asked for information as to just how resistant to UV radiation their covers are, the representative said he couldn’t tell us — not without laboratory analysis. Push come to shove, he did say that ADCO tire covers were “in some way UV resistant.”
The Tire Industry Association’s Bozarth also told us that tires that are not completely covered with some material that resists UV radiation are susceptible to radiation damage wherever they are uncovered. UV radiation doesn’t have to fall directly on a tire — it can “bounce,” as it were, and cause damage to the back side of the tire if unprotected. He did add that the additional heat captured by a black tire cover was not a concern in terms of damaging a tire.
Mr. Bozarth said his best advice for RV owners when it comes to tire longevity is this: Don’t let your tires stand idle for months at a time. Tires are manufactured with anti-ozonate chemicals which travel to the surface of the tires to protect them against UV radiation. However, these chemicals only migrate when the tires flex — meaning, the tires must be driven on to flex. He recommends that an RV be driven a bit every one to two months for best protection.