We use a lot of used tires on our stuff and I see a lot more failures on cheap import tires than I have ever seen on aged tires. Since matching doesn't matter as much on my trailers, I usually buy old spares at the pick-a-part yards for them. Full tread tires that haven't seen much sun and are often 10, 12, 15 years old or older. I don't have any more problems out of 15+ year old tires than I do out of 3 or 4 year old tires.

But on the newer cheap import tires, they often bust cords or throw their treads while still having 1/2 tread or so on our cars. Just plain poor construction.

So in my experience, the original construction of the tire is far, far more important than the age of the tire.



P.S. The number of tires that I mount that are not round is a real shocker. Sounds weird, but is true. Another example of poor construction.