Many of us probably never put on enough miles on some of our cars to wear out a set of tires.

So at what age do you start to worry and junk them ? if stored inside out of the uv spectrum ?

I have a couple sets 20+ years on them....look good... no cracking or dry rot, but I sure think of it when spedo hits triple didgits....I know that is high risk ?

I wouldn't run them at that age no matter how good they look.

Shoot...I wouldn't do 100 mph with a NEW set of those tires!

give 'em to me, and i will dispose of them properly.

how about 125+?;)

We all know of a nasty black Road Runner that's been 140+ with them. I installed mine last year. I did a weekend at Norwalk running 107 mph most runs. I've had the car over 110 multiple times.

A lot depends on the environmental conditions and how they affect the compounds used in the various layers of the tire but particularly the outer.
After Pikes Peak was fully paved, Jess Neal won the vintage class using a set of original BFG R1. Key was storage environment. Race compounds are even more senstive to environmental heat cycling than normal compounds so this is an unusual case. However it is a good example that age alone is not the only consideration when assessing condition.

well, when the tire goes pop and you crawl out to assess the damages then you find out you shouldn't trust your life or your car to 20 year old tires.

Use your COMMON SENSE....20+ year old tires? Not me!

The old tires will be good right up until they are not. The only problem is, that line can change very quickly, you seldom know when it is before hand, and it might only change with one tire, or all of them.

In my best Clint Eastwood voice, "Do you feel lucky today?" Its your car. I prefer not to take the chance. Gene

As to the old tires no I wouldn’t use them. The new ones at the track the tire really doesn’t see to much heat which is what kills them.

No need to wonder. There's a test for this.

On a relatively new tire, depress the tread with your thumb and note how pliable and soft it is. This is how a tire should feel.

Repeat this test on old tires in question. If there's a big difference, if hardness and brittleness are detected, the tires are too old. It's time to replace them with new tires no matter how much tread is left and even if there is no visible cracking.

I have a Wide Oval tire that's almost 50 years old, and it's not cracked, probably because it was a spare kept out of sunlight. It's rubber is so hard I could not dismount it myself using a 12-ton press. Had to take it to a tire store.