TRAVELING AT HIGHWAY SPEED, THE RIGHT REAR COOPER 31X1050R15 TIRE TREAD SEPARATED, CAUSING MY CHEVROLET SUBURBAN TO ROLLOVER 1 AND 1/2 TIMES. THESE TIRES WERE 21 MONTHS OLD, WITH APPROXIMATELY 45,000 MILES ON THEM. THEY WERE ROTATED EVERY 3000 MILES, THE CAR WAS ALIGNED EVERY SIX MONTHS AND I CHECKED THE PRESSURE REGULARLY. I HAD A TREAD SEPARATION WITH MY PREVIOUS COOPER 30X950R15. THE DEALER SAID MY LOAD WAS EXCESSIVE FOR THE TIRE SO I WEIGHED MY TRUCK AND HE RECOMMENDED THE 1050R15S. THE SUBURBAN DID A GREAT JOB OF CRADLING US AND FORTUNATELY WE DIDN'T HIT ANYTHING ON OUR TUMBLE AND SLIDE INTO THE MEDIAN. *NLM