What Mr. Martin said about Michelin tires is spot on. I got more than three years out of them, but only 25,000 miles and that was for the 295 80 22.5 size. Could not believe it when they cracked. Remember, no matter what tire you get, they are only good for about six years. If that is the case, no sense spending a bunch of money on them. Toyo's are very good, so are Hercules.
I always hear about the sun's ultraviolet rays cracking them, but I've talked to knowledgable people who claim it is really oxygen 3. Oxygen 3 is a very corrosive component of the earth's atmosphere.
He is right about going to 295 75 22.5. much better ride. Plus they are a common truck size.
Loren