[Sirrotica]

The problem with newer rubber compounds is they don't stay bonded to the belts like older rubber did. Once the bond breaks down the rubber delaminates from the belts and pressure and centrifugal force pulls the rubber off the tire. I've seen old tires blow out when stored in a garage. Looking at the outside of the tire won't show you squat unless the deterioration already made a bubble or tear. I don't automatically throw tires away at 6 years, (have some 6 + year old tires on my daily driver) but after 8 years the probability of rubber separation goes up disproportionately rather fast. The 6+ year old tires on my 99 GP also DO NOT grip the road well at all. In turns they understeer badly when pushed hard, and the rear will start to slide if I enter a curve fairly hot. They're probably going to be replaced soon because I know they're going to suck in snow.

Race tires lasting more than a couple of seasons never happens, they lose traction abilities rather quickly and also the heating and cooling cycles. Sprint car tires can seal over in one race and loose the ability to grip the track during a yellow or red flag. I just don't think that the tire manufacturers can get consistent rubber batches day after day. NASCAR teams are always saying they got bad tires and they're brand new from the same plant and manufacturer.

One thing I don't understand is if a tire has never been mounted and sits in a warehouse that the tire manufacturers say that up to 4 years In a warehouse is perfectly fine. If oxidation is the problem these tires are exposed to oxygen the minute they're out of the mold...…….

One other thing is the older belted tires would never last as long as radials do, so many times the tire wore smooth long before the rubber broke down, just what I've observed over my lifetime. Bias tires were lucky to go 20,000 miles, radials last 1 1/2 times that if they have any type of care taken to them. So the casings have to last longer just by tread life being extended.

RV tires, such as trailer tires are one of the sorest points in tires, since they sit more than they are driven. I've thrown 4 tires away from my fifth wheel camper just because UV exposure breaks them down very fast. I did try to use the best one on a 5X8 utility trailer and it blew out on the 400 mile trip from home to Norwalk and back. Only had a 500 LB go kart in the trailer, those tires were made in USA and were just to far deteriorated to even be used at a small fraction of their rated capacity.