1998 Pontiac Firebird Owner's Manual - Page 304

Temperature -- A, B, C The temperature grades are (the highest), B, and C, A 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 life, tire and excessive temperature lead to sudden tire can failure. The gradeC corresponds to a levelof 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 gradefor this tire is established for a tire that properly inflated and not is overloaded. Excessive speed, underinflation,or excessive loading, either separately or combination, in can cause heat buildup and possible tire failure. Scheduled wheel alignment and wheel balancing are not needed. However, if you notice unusual tire wear or your vehicle pullingone way or the other, the alignment may need tobe reset. If you notice your vehicle vibrating when driving ona smooth road, your wheels may need tobe rebalanced. Wheel Replacement Replace any wheel that bent, cracked,or badly rusted is or corroded. If wheel nutskeep coming loose, the wheel, wheel bolts and wheel nuts should be replaced.the If wheel leaks air, replace (except some aluminum it wheels, which can sometimes be repaired). See your dealer if anyof these conditions exist. the Your dealer will know kind of wheel you need. Each new wheel should have the same load-carrying capacity, diameter, width, offset and mounted the be same way as the one it replaces. If you need to replace any of your wheels, wheel bolts or wheel nuts, replace them only with new GM original equipment parts. This way, you will be sure to have the right wheel, wheel bolts and wheel nuts for your Pontiac model. Wheel Alignment and Tire Balance The wheels on your vehicle were aligned and balanced carefully at the factory to give you the longest tire life and best overall performance. 6-51