A LITTLE OVER 2 YEARS AGO I PURCHASED 2 SETS OF FIRESTONE 721 RADIAL TIRES (TOTAL OF 8 TIRES). ONE SET FOR MY PICKUP AND THE OTHER SET FOR MY CADILLAC. AS OF THIS DATE ALL THESE TIRES WOULD HAVE LESS THAN 15,000 MILES ON THEM. I HAVE HAD ONE BLOW OUT ON MY PICKUP, TWO OF THESE TIRES WENT BAD (LARGE BUBBLES IN THEM - TREAD SEPARATING FROM BELTS) AND ONE TIRE ON MY CADILLAC BLEW OUT. THE BLOWOUT ON THE CADILLAC CAUSED IT TO BE DESTROYED BY FIRE. IF YOU WANT MORE DETAILS ON THIS, PLEASE LET ME KNOW.( DOT NUMBER: VDHHF70 TIRE SIZE: 225X15 )