Steve, a reader of RVtravel.com, asked:
Just gonna say it, covering one’s RV tires just for a weekend is not necessary. With that said, when should one cover RV tires: when stationary for a week or longer, full-time parked, or anytime when parked? I cover ours when parked at the house, but for a week or so getaway, it seems silly. The tires aren’t going to rot off the rim in a few weeks.
You are correct, Steve. Not covering your tires for a day or a week is not going to make them fail and fall off the wheel.
Information to help extend the life of tires
But my objective is to provide information that can extend the life of your tires.
Just as with tire covers, it is not likely that running your tires 1% or 5% overloaded is going to make the tires fail the next day or week. Neither is running 10 psi low going to cause an immediate “blowout”.
“Tire life” is not an on-off switch, just as the level of oil in your engine being 5 oz. low is not going to result in an immediate engine failure. But if you run a little low on oil and run a little long between oil changes and run a little hot because you are low on coolant and you run the engine at higher RPM, etc., I think you will agree that it would be unreasonable to expect the same “life” from your engine as someone that never did those things.
If you bought a length of rope that was rated for 1,000 lbs., it is unlikely to fail at 1,010 lbs. But maybe if you load it to 1,010 lbs. for a few thousand times it will more likely fail. It might even fail at 1,009 lbs. if you leave it with a load for many months.
I can’t think of any product that will always fail as soon as you exceed its rating by 0.5%, and tires are much more complex than a piece of rope.
Time at Temperature function
One thing that makes tires more difficult to rate for their max life is that there is a Time at Temperature function involved. In February of 2012 I provided an example of how tires and other “organic” products must be treated differently than things made of steel or stone.
As that example shows, a tire may pass a certain test if the test is completed in a relatively short time, but the tire will fail if you spend more time “outside” the recommended strength or temperature limits.
The number of hours a tire is in full sunlight is not a “hard” number, just as the temperature achieved from being in direct sunlight is not a “hard” number.
More hours at higher temperatures make it more likely for a tire to fail. But just as you could not tell me the total number of hours you had the tires on the left side of your RV in full sunlight versus the hours for tires on the right side, I cannot predict a tire’s life due to the numerous variables in load, speed, temperature, etc., it is subjected to.
Damage done by exposure to sunlight
I can provide a real-life example of the damage done by exposure to sunlight. Years ago I parked my RV in the same location. This resulted in the driver’s side being in direct sun for many more hours than the passenger side. At 5 years of life, the vinyl graphics and paint on the driver’s side were severely cracked, but the vinyl and paint on the passenger side were nowhere near as badly cracked.
The driver’s side needed to be ground off, repainted and new vinyl applied.
Other areas had a significantly different and lower level of failure.
Tire damage is always cumulative as there is no tire I have ever seen or heard of that will “repair” itself once the air is put back in the tire after running low. The same goes for chemical properties being degraded due to sun exposure.
The facts are: The sun heats up your tires. Heat degrades the strength of the rubber. The damage is cumulative, so less exposure to the sun’s heat is better for a tire’s life.
Check out my Blog www.RVTireSafety.Net
Have a tire question? Ask Roger on his RV Tires Forum here. It’s hosted by RVtravel.com and moderated by Roger. He’ll be happy to help you.
Read more from Roger Marble on RVtravel.com.
We use our Class B as a second family vehicle. So I rotate the way it is parked to share the sun’s exposure between the two sides, The tire covers were a real hassle to put on and take off so often.
I quit using tire covers because spiders and other undesirable creatures would move in when we were parked at home. Instead, I fashioned some leftover plywood to cover the tires. I painted them white. I just have to re-paint them from time to time. When traveling I don’t bother covering them.
Everything is of a cumlative nature in the real world. From a Plumbing & Heating business owner. The final failure incident is preceded by many incidents of a less serious nature.
I used to cover them religiously when parked at home. Due to the covers being filthy when I remove them, I have gotten lazy about this. But this article, I will start again after our current trip.
Roger, instead of applying new vinyl, why not paint the design. We did that to our 2006 Winn Aspect, when most of the decals were peeling and cracking. Much better, IMHO.
I was lucky. I got to the right person at the right time with the right information to convince them that they had a “bad batch” of vinyl graphics. RV Co sent me replacement graphics for one side of my class-C. I had the tools and knowledge to do the re-paint for the cost of a couple of qts of automotive paint. (White is the least expensive too.)