[n0useforaname]

I just read some article that stated the Load ratings, and their PSI, and how much they are rated to carry. Here is the article:

A "D" rated tire at about 3,300 lbs. at 45-50 psi ain't much better. My 40ft 5th wheel weighs 3,300 lbs. at the hitch pin, plus the hitch, firewood, coolers, a couple of gas cans and a toolbox, we're up to about 4,000 lbs. A load which a one ton truck's suspension can handle with ease. Add that 4,000 lbs. to the 3,000 lbs. the rear of the truck weighs and you've got a problem. Even with a "D" rated tire you are as much as 1,000 lbs. overloaded.

A tire is basically a balloon that holds air. The bigger the load the more air pressure you need to support it. The limiting factor a tire has is it's ability to contain pressurized air and to withstand as well as dissipate heat. The bigger your load and the faster your road speed, the more heat is generated. This is also magnified by tire flex and outside air/road surface temperature (Ever notice the thousands of blown tires along the highways in the desert?).

What it boils down to has happened to me a dozen times. As the tread wears on my 35" load range "D" tires to about 50%, its ability to dissipate heat is reduced dramatically. The tread lugs work like the cooling fins on a radiator, giving a tire more surface area. As the tire loses its ability to to shed the heat of being overloaded three things begin to happen:

The tread begins to separate from the carcass.

The carcass begins to shear and the cords/plies separate.

The tire becomes distorted or "out of round."

Obviously any or all of these conditions will lead to more flex, more heat generated and to premature and probably catastrophic tire failure. If you've ever had the tread separate from a 38x15.50R16.5 tire at 70+ mph, you know what a 70 lb. piece of rubber ten feet long and 16" wide can do...

Every tire I've ran, regardless of manufacturer has done the same thing. At 50% of tread wear, the carcass splits apart or the tread separates, while towing! Never empty, never on the way to the Safeway, always towing under a load...