Roger Marble is a tire professional that I have had contact with for a few years on tire issues. He recently emailed me with the following recent tests:
"It is well known that heat is one of the major killers of tires. It is a little less well known that one of the reasons tires seem to age at different rates is their different temperature history and tires are basically always "curing". Ever seen how hard a 40 or 50 year old tire is?
"It is known that chemical reaction rates (1), in general, double every 10°C (18°F) so the more hours we keep our tires at higher temperature the more cumulative "accelerated aging" we are doing to our tires.
"While keeping the proper inflation pressure in our tires can keep the operating temperatures relatively under control ( +20°F to +50°F) above ambient while driving down the highway. One area I have not seen any data on is the temperature of a tire just sitting in the Sun."
Roger took temperatures as follows:
- 85.1 degrees Of side of RV in the shade
- 107.9 degrees Of side of RV in the sun
- 136.1 degrees Of a tire in full sun
- 98.6 degrees Temperature of his white tire cover
- 99.5 degrees Temperature of the tire under the cover
"I think It could be argued that your tire 'ages' between two and four times faster if you do not use a white tire cover then when your tires are in full sun when parked.
"Another way to think of this could be that 6 months of full exposure to bright sunlight does as much heat damage to a tire as two years under a white tire cover.
"I will have to leave it up to someone else to do a test on black tire covers.
"How 'old' are your tires?"