Originally Posted by mordecai
Thanks for all the great info, here and on your blog also. How important is it for tire longevity to periodically put some miles on trailer tires. I just got 5 new tires and am thinking that if the spare never gets rotated into the mix it's not aging as well as the other 4 because there is no working of the rubber compounds in that tire. Does that set me up for it to fail if I ever have to use it?
While I have read many posts that suggest that you will get longer life from tires if you "exercise" them I have not seen any actual test data that supports this.
The intent of this thread was to try and summarize what I consider "best practices" for tire life longevity, while at the same time trying to keep the level of activity involving tires to a reasonable low level.
Here I would want to keep it as cool as possible and out of direct sunlight (UV) and if possible away from excess ozone. Of these three negative conditions staying cool is the biggest bang for the buck.
UV and Ozone attack the exterior of a tire and long term exposure to either of these conditions can result is undesirable cosmetic condition of cracking on the surface of the tire. Sometimes the misnomer "Dry Rot" is used.
Heat however can hurt the structure of a tire and this can lead to actual failure.
Ozone and other forms of air pollution are pretty hard to avoid and unless you can place the spare in a sealed trash bag I don't know of any way to reasonably protect a tire.
UV is a little easier. Keep the tire out of direct sunlight. Again a plastic bag will work. So will tire covers or even a sheet of cardboard or lumber. In other words you can drastically reduce the exposure to UV with almost anything.
Heat is the tire killer. I have written in my blog
how temperature accelerates the aging process of tires with the rate doubling with each increase of 18F.
So =+18 = x2
+36 = x4
+54 = x8
Tires run hotter when the inflation is lower. They are being heated by the sun when sitting at a campground in full sunlight and they are BAKED if stored under a a black cover and fried when hung off the back of an RV or SUV.
Here is my blog post on Tire Covers
with data to show just how helpful they can be.
Here is what I have done. My spare is mounted inside my large storage bay. I have white covers that I use whenever parked for a day at a campground.
Only time I do not use the white covers is when at home, in the "car port" that provides full shade or when camping in the rain.
I keep the tires clean by washing with the same soap I use on the side of my RV and I only use an old cloth as stiff bristle can leave microscopic scratches on the surface and will remove the "wax" and UV protectants built into all tires.
I see no reason why the spare could not be "rotated" into the mix with the other 4 tires and that might improve the longevity of the set.
I assume of course that you have confirmed that no tire is overloaded.
Be sure to do an annual inspection
and to keep the TT tires fully inflated to the pressure on the sidewall.
As Tony suggested the use of TPMS on the ground tires will help with their longevity. I do check the pressure in my spare at least once a season.