1987 ford 350 box van, one original rear tire blew in 2000, the set now are 17 years old but I'm afraid of them so I'll get some new ones. Might have 4000 miles in them. My 2006 3500 Dodge truck came with Michlens, replaced those in 2016 because I got a good deal on take offs from a 2016 3500. They had... 96,000 miles on them, you could see the air in them they where so wore out and they where cracked up bad. Each one might have had five patches in it. They where 8 or 10 ply tires. I've always said the "rubber" of today is not as good as 40 years ago, almost designed to go bad so more tires are bought. If you have an old car and quarters are hard to find, tires are cheaper, don't take a chance. Besides, the old ones are easy to sell.