NWGA, you read it correctly. I stretched it, but my lame excuse is I rarely drive highway and only put 800-1500 miles per year on each car. I also keep both cars garaged and covered, and check the tire pressure monthly. Both cars had about half the tread remaining and no cracks, nor had they ever been patched. But there is a definite element of risk.

Discount Tire, where I buy all my tires, states six years is the useful life and they will not service a tire over 10 years old. I was planning on replacing them the last two years, but rarely drove the cars and just kept pushing it out. But 14 was my limit. I kind of consider the new ones as lifetime tires because in another 10 years I will be 84yo and may not be able to get in/out of these cars.

If I was replacing them every five years, they would have only 5000 miles on them and most of the tread. I know the answer is to drive them more, but the 2-3 long trips I take in the summer, I prefer to drive my 2018 Maserati Ghibli. Much more comfortable, and plenty of room for gifts going out and beer and scotch coming back. Today I went to two grocery stores and a lawn store with the roadster, total less than 20 miles. But a delightful drive with the top down.