1997 Pontiac Bonneville Owner's Manual - Page 301

Temperature -- A, B, C The temperature grades are A (the highest), B, and C , representing the tire'sresistance to the generation of heat and its abilityto 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 gradeC corresponds to a level of performance which all passenger car tires must meet under the Federal Motor Vehicle Safety StandardNo. 109. Grades B and A represent higher levels of performance on the laboratory test wheel than the minimum required by law. Warning: The temperature grade for this tire is established for a tire that is properly inflated and not overloaded. Excessive speed, underinflation, or excessive loading, either separatelyor in combination, can cause heat buildup andpossible tire failure. Scheduled wheel alignment and wheel balancing are not needed. However, if you notice unusual tire wear or your vehicle pulling one way or the other, the alignment may need to be reset. If you notice your vehicle vibrating when driving on a smooth road, your wheels may need to be rebalanced. Wheel Replacement Replace any wheel that bent, cracked, or badly rusted is or corroded. If wheel nuts keep comingloose, the wheel, wheel bolts and wheel nuts should replaced. If the be wheel leaks air, replaceit (except some aluminum wheels, which can sometimes be repaired). See your Pontiac dealer if any of these conditions exist. Your dealer will h o w the kind of wheel you need. Each new wheel should havethe same load-carrying capacity, diameter, width,offset and be mounted the same way asthe one it replaces. 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. 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. 6-48