By Roger Marble
This is a reprint of a post I did in 2014 on UV tire protection. The facts and data have not changed.
This investigation has taken more time than I originally wanted as I needed a reasonable way to measure UV and a day with full sun – not something easy to find in NE Ohio.
The test uses a Hawk2 UV meter. This unit is intended to help you judge how much sun you are getting while at the beach. But I felt it would serve my purposes as we are not trying to measure an absolute value in milliwatts per square centimeter. We’re just testing for a gross relative level of shielding of different materials used to cover tires.
I set up a test using my RV
As you can see, the UV of 6 years here in Ohio has pretty much destroyed the cheap vinyl side decoration. Anyway, the front tire has my normal white vinyl tire cover. Also, there is a standard blue tarp, a roll of window screen and some black cloth-backed vinyl similar to what is used in black tire covers.
I will show the meter readings for each “shield”
(Click any image to enlarge. Note the UVI is the bottom left number in the meter screen.)
Full sun gives a reading of 9, which is considered “HIGH”:In full shade, the reading is zero:Under the white cover the reading is zero:Even under the black cover the reading is zero:But the screen only reduced the UVI to level 5:
How I interpret the test results for UV tire protection
I interpret these results to indicate that anything that is not in direct sun or that shields all direct sunlight will provide adequate protection from UV damage for tires.
Don’t worry about reflected light going under the RV to the back side of the tires as that is full shade. After all, tires are designed to be outdoors and we are not trying to protect tires for 20 years. We’re only trying to get past a normal vehicle usage of 4 to 5 years to the 8- to 10-year range for many RVs. I would not consider open mesh as used in some “tire covers” complete protection. However, it is probably better than nothing.
NOTE: I did not address the effects of heat on tires in this post. I did cover it in THIS post, and that clearly shows that white covers are the ones to use if you want to keep your tires cooler so they age more slowly.
If you want to protect your tires to give them the longest life possible, you need to cover them with white solid covers. Cloth-backed vinyl would be the most reasonable option.
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