UV damage to tires

My mother-in-law lives in Florida and is telling my husband and I (we live in Colorado which has lots of sun) that when she took her car to the shop to check what she thought was a slow leak in one of her tires, she was told that they were deteriorating due to the sun. We’ve never of heard of that here. Is this valid?

It’s possible, but rare. How old are the tires?

We’re not sure. I’ll find out tomorrow and post it.

OK. Here’s how to get the date off the tire: http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=11

True. You have no sun compared to Florida. It gets hot down there (next to the pavement). I’ve heard that the sun can damage your skin too.

How old the tires are is a big factor. When they took off the tire to fix the leak they may have noticed signs of tires too old to be using. It’s common for our older Moms to be running on tires 10 to 20 years old because they don’t put on the miles. Like belts and hoses, old tires can look new and be rotten. UV, heat and time all break down tire material. For the rest of us, the top of Lincoln’s head appears on the tread and we never deal with ‘old’ tires. Have Mom give you the shop number and call them. She may need new tires and it would be good to know if the tire shop boys are looking out for her.

I’ve heard that the sun can damage your skin too.

As someone who has had over 12 surgeries for melanoma (cancer) and so far outliving a 30% chance of living 10 years by over 40 years now, I can tell you that it certainly can damage your skin.

I Highly recommend some serious sun screen for anyone who is out side often. I suggest UVA & UVB protection with a rating of 50 or more. This is serious stuff.

Sorry about going off topic.

There’s a big difference in the power of the sun in Colorado and Florida. Florida has much more direct sunlight and longer periods of daylight, being much closer to the equator than Colorado. This makes a big difference in annual UVA and UVB exposure.

Also, if her driving habits are similar to my MIL, she could have 10 year old tires with 20,000 miles on them. Park a car outdoors in FL for 10 years in that sun, and the tires could easily be compromised by the UVA and UVB exposure. No doubt about it.

Rubber is an organic material, and just like skin, there are things rubber does not like.

  1. Oxygen: Oxygen is a very active element, particularly in the form of Ozone - which Colorado has in abundance due to its elevation.

  2. Heat: Chemical reactions double for every 10?C rise in tepmerature. So Phoenix is going to have more problems than Denver.

  3. UV: Again, higher elevations work against Colorado here.

  4. Flexing: The more flexing, the more likely the rubber is to crack. A leaky tire is going to flex more, and show portionally more cracking.

Recent bulletins from the tire industry indicate that tires degrade simply due to time. The age of a tire is important even if the tire is unused. There some disagreement over how to best express this age limitation, but my take is:

If you live in a hot climate (AZ, CA, NV, TX, and FL) then the limit is six years. If you live in a cold climate (MN, ND, WI, MT, etc), then the limit is 10 years. States in between are … ah … in between.

Here’s a lot of detail on how to read the DOT code on tires:



Been there, done that.
I’ve watched it happen.

1979 c10 pickup stays parked most of the time ( 70,130.07 total miles on truck ) and a few years back I was noticing the great numbers of teeny tiny surface cracks in the tires and how they no longer felt ‘rubbery’ but smooth and hard.
– Began tires savings account.
As I exited the house one day, weeks thereafter, the left front tire was flat as a pancake. Just sitting there, with maybe 2000 miles on the tires, pffffth !

Yes it’s valid.

Now I have tire covers ( sold to boat and r.v. owners ) for that truck’s third set of tires.

( 4 corners New Mexico @ 6500 ft )

For UV, altitude can easily be a bigger factor than latitude. Florida and Colorado should both be bad, Colorado depending on altitude.

“Sorry about going off topic.”

Personal safety is never off topic. Thanks for the excellent advice, Joseph.

I don’t believe that ultraviolet light can damage a tire enough to require replacement. UV light only penetrates a few Angstroms before it is fully absorbed by the tire, and these sidewalls are thick. Therefore, the only place it could be a problem might be the bead. I don’t believe that light can get into the bead area, so that’s off the list, too.

BTW, there are 10,000,000 Angstroms per millimeter. You’d need a lot longer than a few years to degrade the sidewalls enough to cause failure, even if they were a mere millimeter thick.

Tell that to my popped Uniroyal.

Ozone is a major problem for rubber, maybe that’s what is affecting the tires.

perhaps, but the truck gets parked facing the same westerly direction all the time. The left side exposed to the daily arc of the sun, with the rear closer to the shade of an elm, the fronts turned slightly to the right.
The left front just blew flat while sitting there parked.

Dumb humanities major question: Could the difference in longevity from one side to the other be because the ones on the left side flexed slightly from the warming/cooling cycle of sunrise/sunset while the others not exposed to the sun did not see such variations and so lasted longer?

Some tires resist weather checking MUCH better than others. So I suspect UV resistance is something a manufacturer can control during the manufacturing process…Tires seldom last long enough for this to become an issue…But in the South-West, many motor-home and R/V owners buy and use tire covers when they are parked for any length of time…