RE: Tire Rot
I'd be willing to bet that there is another factor beside ozone etc. in the
'tire rot' equation.  Today's tires use some complex chemistry in the rubber
compounds in order to achieve certain handling, traction and wear
performance.  I'm guessing here but if the chemical mix or the curing
process is just a little bit off at the factory then the rubber will
continue to cure over time similar to the deterioration in some plastics
over time.  Only a guess on my part.  Any chemists out there that have
worked with rubber that can comment on this?