I've got Carlisle turf tires on my PT425. They came one it new in 2001. They still have 95% of the tread, even some of the **** are still on them. 500+ hours. I destroyed one due to operator abuse, but they are for all intents and purposes still perfect.
I've got Nokian tires on my Suburban. 5 years old. Still in good shape. No visible cracks.
I've got some off-brand tires on my 2002 car hauler trailer. Still look like new. However, the trailer is always parked on the north side of my garage so the tires are rarely exposed to UV light.
I can honestly say I've had zero tires crack and I drive em till they drop.![]()
I had to learn the hard way that constantly parking tires on dirt can accelerate tire deterioration.
Another local factor is ground-level ozone.... high levels are tough on rubber, amongst other things.....
Rgds, D.