On 10/27/06 (@ 30,048 miles) i purchased 4 tires (sumitomo htr h4; p195-60-r15; 87h m+s). rotation of these four tires occurred @ 34,917 miles. on 7/27/07 a driver's side tire went flat and was replaced where i originally purchased them. driving off the freeway damaged the tire into two pieces (sidewall still attached to rim), so determining what caused the flat was fruitless. next service occurred @ 41,640 miles and included rotation and alignment. then on 12/29/07, the rear passenger tire went flat, although the tread looked fine with no visible punctures. appx three hours later, the front passenger tire went flat and this time damage was visibly seen on outside sidewall of tire. again, no visible puncture on tread. i still have this tire. *tr