We had the four rears changed out a couple weeks ago. They were GY670s, 13 years old.
They looked perfect except a bit of shoulder wear on one. they were soft and supple and hand no cracks or crazing or anything.
Looked on the inside, after they were dismounted, and looked perfect.
We store ours inside too.
I got the feeling of being a sucker and tires could have gone another decade.
Our Mhs don't , or most much over 30,00 lbs and the tires generally are designed for the punishment of 80,000 lbs+ semi rigs.
Pur tires never got hot. The one inside tire near exhaust ran about ten degrees warmer than the others. In Az in over one hundred degree heat the ties never got over 125 region.
Would they actually last another decade: maybe/perhaps/probably/maybe not.
I don't know. I don't think they would sell many tires if they would self destruct when they got to five years/ten years/or thirteen years old.
Michelin Dealer Salesman said the Michelins are guaranteed for 7 years but ht Mgr chimed in that tires have no set life span. Even with checks etc the tires may be good for a long time. Depends on their review apparently.
If I had sturdy wheel cans, which coaches should have but most don't, I would have made the choice to keep the old tires on a lot longer.
Dollars to donuts I bet some semi driver got some free tires or some farmer did and the GY670s will be rolling for some time to come.
They can't sell them if over 5 years old. I do know the two taken off the steer axle three years ago are running around on anot for hire rig in Indiana. They are 13 years old, now, too.
I made the safest choice based on current opinions.
Perhaps there is some outfit that can look at the tires with instruments,x ray,gas chromagraphs, molecula makeup or some such and say safe r unsafe.
I bet there is some such equipment as Tire Companies, would be foolish to produce questionable tires or tires they don't know how long they will function, for the purposes sold for and the huge sums involved, in liability.
It is to their advantage to leave Customers guessing and gambling on the safe side and buying more tires. It is not to their advantage to produce tires that are a gamble however.
Of course they do it with rethreads, all the time, as do China bombs, and marginal, get the rigs out the door,as cheap as possible tires, of some towables, or did.
Analytically I believe I could have gotten a lot more usage out of the old tires, but like I said, I made the right decision based on opinions,in the absence of a knowledgeable analysis, of the tire structure and materials in current state.
