21.   Many of the complaints involve sudden tread separation.

22.   NHTSA officials say the sway bar problem did not cause tread separations on Firestone tires that were used on the Explorer.

23.   NHTSA continues to receive complaints as it investigates what is causing the tread separations, blowouts and other problems with the tires.

24.   Saurer said enlarging the part would help tires withstand tread separation.

25.   The safety of the Explorer, its best-selling sport utility vehicle, came into question after several rollover accidents that followed tread separations in Firestone tires.

26.   Vaughn said there have been no reports of tread separation involving ATX spare tires.

27.   When asked by Judge Filemon Vela if tread separation was the result of a problem with Ford Explorers, Lampe said company research so far was inconclusive.

28.   The SUVs were all equipped with Firestone tyres many of which suffered tread separations at high speeds.