[DanEC]

I don’t think there is a conclusive way to factually answer that question. A car garaged most of the time should help protect the tires from some degradation on the exterior side, but it’s hard to tell what’s going on inside or even internally to the tire carcass. I’ve had 20 - 25 year old tires on some of my old cars and a set of Coker red lines on my GTX are pushing 20 years right now which most critics of their tires will tell you, would seem impossible. But I seldom drive the car and when I do I don’t push it hard and I don’t drive any sustained highway speeds in the car - I just amble down to the local cruise night in it every couple of months and get on it in first and second a little when the mood strikes. But, if you intend to really drive your car and sometimes dip fully into its performance potential, then I would say you should retire those tires for safety reasons. I think. 5 years life is normally discussed for daily driver cars. IMO, ten years for a weekend cruiser, otherwise garage queen is reasonable (some will disagree and some tires will develop thread separation due to poor quality earlier). After that I would keep a close eye on them and don’t push them at all if you decide to postpone replacement.