1993 Ford 4630, 1972 IH 140, 1970 IH 140, 1975 IH Cub, 1949 John Deere A
The Ford 4630 we have, I just put a new set of Firestone's on it last year cause I ran a large stick through one of them. The ones that were on it, they were original from 1993 and had good tread, they were just getting thin and that was the third time I'd had a flat from running something through one.
My 2006 Kioti rear tyres are still in perfect condition. Only checked the pressures twice and no loss of air. No signs of cracks or perishing.
The front tyres however should never have been fitted to a tractor with a FEL as they were too soft when the FEL was used.
I replaced them with heavy duty tyres a few years ago and it has been great since.
John Deere 4310 CUT, Ford New Holland 575E Industrial Backhoe, John Deere F725 Front Mount Mower
I ran an old Massey with R1s for 10 years with lugs missing and cord showing before one blew. My JD4310 had bald fronts and cracks all the way around on one of the rears so I replaced all four. Don't know if or how long they might have run but they were already 14 years old.
I got new front tires for my kubota when they wouldn't hold air anymore and couldn't be repaired. I don't know how many years that was, but I'm sure it was more than 13. I had 25 years on my rear tires before I had to replace them. If the tire is more of a hassle to air it up and repair it than I want to put up with, then I will replace it. I have a front tire on my JD that is 10 years old, I ran over a thorn several years ago and have had air leaks in it ever since in spite of several attempts to fix it. I'm considering replacing it even thou it is in good shape.