1993 Buick Century Owner's Manual - Page 258

Temperature-A, B, C Wheel Alignment and Tire Balance The wheels on your vehicle were aligned and balanced The temperature grades are (the highest),B, and C , A carefully atthe,factory to give you the longest life and tire representing the tire's resistance to the generationheat of best overall performance. and its ability to dissipate heat when tested under controlled conditions on a specified indoor laboratory In most cases, you will not need to have your wheels test wheel. Sustained high temperature can cause the material'of the tire to degenerate and reduce tire life, andaligned again. However, ifyou-noticeunusual tire wear excessive temperature can lead to sudden tire failure. The or your vehicle pulling one wayor the other, the alignment may need to be reset. If you notice your grade C corresponds to a level performance whichall of a passenger car tires must meet under the Federal Motor vehicle vibrating when driving on smooth road, your wheels may need to be rebalanced. Vehicle Safety StandardNo. 109. Grades B and A represent higher levels of performance on the laboratory Wheel Replacement test wheel than the minimum required law. by Replace any wheel that is bent, cracked or badly rusted. this Warning: The temperature grade for tire is If wheel nuts keep coming loose, the wheel, wheel bolts, established for a tire that is properly inflated and not and wheel'nuts should be replaced.If the wheel leaks air overloaded. Excessive speed, underinflation, or excessive out, replace it (except some aluminum wheels, which can loading, either separately in combination, can cause or sometimes be repaired). See your Buick dealerany of if heat buildup and possible tire failure. these conditions exist. Those grades are molded on the sidewalls of'passenger Your dealer will know the kind wheel you need. of car tires. Each new wheel should have the same load carrying While the tires available as standard or optional capacity, diameter, width, offset, and be mounted the equipment on General Motors vehicIes may vary with same way as the oneit replaces. respect to these grades, all such tires meet General Motors performance standards and have been approved for use on General Motors vehicles. All passenger type (P Metric) tires must conform to Federal safety requirements in addition to these grades. 256