Tires break down for several reasons. All of them to do with chemistry...
The most significant source of damage is ultraviolet radiation from the sun. UV light degrades polymers and aramids - and rubber, causing fading, cracking, and degradation of mechanical properties (flexibility). UV damage can be reduced by the use of proper tire coatings and tire covers.
Oxidation causes similar issues, as does water, but at a much slower rate than UV. There really isn’t much that can be done about either. The nitrogen fad from a few years ago was supposed to help, and it does in a very, very limited way for our tires, but really isn’t worth the effort.
Lastly, other environmental chemicals have the same effect, but again, not much we can do about ‘em.
Car tires age just like our RV tires, but they generally get replaced due to tread loss long before they show signs of general aging.
I haven’t found any credible evidence that driving on tires helps them age better, but I haven't looked that hard either. I suspect it has more to do with feeling better about replacing them with visible tread wear rather than looking brand new. Maybe the tire guy will pop in with some actual data.
All manufacturers and experts agree, to get the longest life from our tires:
- Keep them inflated properly based on the coach’s actual weight
- Keep ‘em clean
- Treat the visible bits with a good UV protectant
- Keep ‘em covered when the coach is stored.