1981 FORD F150

I PURCHASED FOUR USED SX 5000 STARFIRE (COOPER) 255/70-15 TIRES FOR MY 1981 FORD F-150 IN MARCH OF 2010. THE TIRES WERE MOUNTED TO WHAT I BELIEVE ARE 15X8 STEEL WHEELS BY THE INDEPENDENT TIRE SHOP THAT I PURCHASED THE TIRES FROM. I THEN DROVE FROM SAINT PETERSBURG, FL TO AUSTIN, TX ON THE TIRES WITH NO PROBLEMS. OVER THE NEXT TWO OR THREE MONTHS, I DROVE ABOUT 500 MILES ON THE TIRES WITH NO ISSUES, UNTIL ONE DAY ONE OF THE FRONT TIRES WAS FLAT IN MY DRIVEWAY, WITH THE TREAD SEPARATED IN ONE AREA. I REPLACED BOTH FRONT WHEELS WITH SPARE WHEELS AND TIRES (UNKNOWN EXACT SPECIFICATIONS, BUT SMALLER), AND WITHIN A COUPLE OF WEEKS, ONE OF THE REAR TIRES (AGAIN, IN MY DRIVEWAY) WAS FLAT, WITH THE TREAD SEPARATED. I PLACED TWO OTHER SPARE WHEELS/TIRES ON THE REAR AND PLACED THE SX 5000S IN MY GARAGE. WITHIN A WEEK, THE TWO SX5000S THAT HAD AIR IN THEM HAD BLOWN, AGAIN WITH THE TREAD SEPARATED. THE FAILURES OCCURRED WHEN THE WEATHER OUTSIDE TURNED HOT (SUMMER). TIRE PRESSURES WERE MAINTAINED NE

THERE IS A HOLE IN THE GAS TANK. DEALER HAS BEEN CONTACTED. *AK