oversteer characteristics following a rear tire tread separation than many of their peers." The Explorer was redesigned for the 2002 model year. The tire pressure was raised to 30 psi, it was widened by 2.5 inches, the suspension was lowered, and independent rear suspension and electronic stability control were added. Firestone tires The tires that were involved in these accidents were P235/75R15 ATX and ATX II tires and P235/75R15 and P255/70R16 Wilderness AT tires. These tires were installed as OEM equipment on the Ford Explorer, Mercury Mountaineer, Ford Bronco, Ford Ranger, Ford F-series pickup trucks, Mazda B-series pickup trucks, and Mazda Navajo between 1991 and 2000. ATX tires were originally developed in the late 1980s for use on Ford light trucks and SUVs and were first installed on Ford trucks and SUVs in 1991. The ATX II was designed to improve the ATX's ride and the fuel economy of the Explorer. The Explorer had one of the lowest fuel economy ratings for any SUV under production at that time, due at least in part to Ford's decision to lower the tire pressure to 26 psi. Ford asked Firestone to reduce the weight of the ATX tires so that it could improve the fuel economy of the Explorer. Firestone created the ATX II by removing material from the tire which lowered the weight by 10%. Removing material from the ATX design also improved the profitability of the tire for Firestone. The Wilderness AT tire was developed in 1993 and was designed to have better snow handling and "irregular wear targets" and had a different tread design than the ATX tires. The Wilderness AT was sold and installed on Ford trucks from 1996 to 2000 and had a temperature and heat resistance rating of "C" which is the lowest rating allowed by the NHTSA's Uniform Tire Quality Grading System. Many of the features of the ATX tires were identical to the Wilderness AT tires. In May 1998 the Wilderness AT tires were redesigned with a thicker belt wedge (see tire design below) although the name of the tire was not changed. The defective ATX and ATX II tires were primarily manufactured at Firestone's Decatur, Illinois factory which produced tires with a significantly higher failure rate than the other two factories that manufactured these same tire models, Wilson, North Carolina and Joliette, Quebec. Wilderness AT tires manufactured before May 1998 had higher failure