2008 Lexus GS 450h Owners Manual - Page 555

6-1. Specifications n Temperature A, B, C The temperature grades are A (the highest), B, and C, representing the tire's resistance to the generation of heat and its ability to dissipate heat when tested under controlled conditions on a specified indoor laboratory test wheel. Sustained high temperature can cause the material of the tire to degenerate and reduce tire life, and excessive temperature can lead to sudden tire failure. The grade C corresponds to a level of performance which all passenger car tires must meet under the Federal Motor Vehicle Safety Standard No. 109. Grades B and A represent higher levels of performance on the laboratory test wheel than the minimum required by law. Warning: The temperature grades for this tire are established for a tire that is properly inflated and not overloaded. Excessive speed, underinflation, or excessive loading, either separately or in combination, can cause heat buildup and possible tire failure. Glossary of tire terminology Tire related term Cold tire inflation pressure Maximum inflation pressure Recommended inflation pressure Meaning Tire pressure when the vehicle has been parked for three hours or more, or has not been driven more than 1 mile or 1.5 km under that condition The maximum cold inflated pressure to which a tire may be inflated, shown on the sidewall of the tire Cold tire inflation pressure recommended by a manufacturer 562 GS_HV_U March 29, 2010 3:31 pm