Temperature – A, B, CThe temperature grades are A (the highest), B,and C, representing the tire’s resistance to thegeneration of heat and its ability to dissipate heatwhen tested under controlled conditions on aspecified indoor laboratory test wheel. Sustainedhigh temperature can cause the material of the tireto degenerate and reduce tire life, and excessivetemperature can lead to sudden tire failure. Thegrade C corresponds to a level of performancewhich all passenger car tires must meet under theFederal Motor Vehicle Safety Standard No. 109.Grades B and A represent higher levels ofperformance on the laboratory test wheel than theminimum required by law. It should be noted thatthe temperature grade for this tire is established fora tire that is properly inflated and not overloaded.Excessive speed, underinflation, or excessiveloading, either separately or in combination, cancause heat buildup and possible tire failure.Wheel Alignment and Tire BalanceThe tires and wheels on your vehicle were aligned andbalanced carefully at the factory to give you the longesttire life and best overall performance. Adjustments towheel alignment and tire balancing will not be necessaryon a regular basis. However, if you notice unusual tirewear or your vehicle pulling to one side or the other, thealignment might need to be checked. If you notice yourvehicle vibrating when driving on a smooth road, the tiresand wheels might need to be rebalanced. See yourdealer/retailer for proper diagnosis.Wheel ReplacementReplace any wheel that is bent, cracked or badly rustedor corroded. If wheel nuts keep coming loose, the wheel,wheel bolts and wheel nuts should be replaced. If thewheel leaks air, replace it. Some aluminum wheels cansometimes be repaired. See your GM dealer/retailer ifany of these conditions exist.5-71
