Traveling east on interstate 10 west of tonopah, az , felt vibration and pulled to the side of the road. the right rear tire suffered a partial tread separation. tire was replaced with spare and trip continued for another 30 miles when the left front tire suffered a complete tread separation causing nearly $1600 dollars damage in and around the wheel well. tires were firestone fr380 p215/60r16 with less than 25,000 miles. subsequent check of tires indicated that the tires were properly inflated. tires had been rotated and checked on a regular basis with oil changes. *tr
Dt*: the contact stated while driving past a roadside radar check, the display read slower than the speedometer on the vehicle. the dealership determined this was a direct result of the steel wheels; they cause an inaccurate reading with the speedometer. the manufacturer determined the speedometer could be false up to 8 percent, after having a radar test, it was determined the vehicle was off by 9 percent.