1994 GMC Jimmy Owner's Manual - Page 283

Temperature - A, B, C The temperature grades are A (the highest), B, and C, representing the tire's its resistance to the generation of heat and ability to dissipate heat when tested under controlled conditionson a specified indoor laboratory test wheel. the Sustained high temperature can cause material of the tire to degenerate to and reduce tire life, and excessive temperature can lead sudden tire failure. The grade C corresponds to a level of performance which all passenger car tires must meet underthe Federal Motor Vehicle Safety Standard No. 109. Grades B and A represent higher levelsof 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 separately in combination, can cause heat or buildup and possible tire failure. These grades are moldedon the sidewalls of passenger car tires. While the tires available as standard or optional equipment on General Motors vehicles may vary with respectto 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. Wheel All'gnmenfand Tire Balance The wheels on your vehicle were aligned and balanced carefully the at factory to give you the longest tire life and best overall performance. In most cases, youwill not need to have your wheels aligned again. However, if you notice unusual tit-e wear or your vehicle pullingone 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 is bent, cracked or badly rusted.wheel nuts keep If coming loose, the wheel, wheel bolts, and wheel nuts should be replaced. If the wheel leaks air, replaceit (except some aluminum wheels, which can sometimes be repaired).See your GM dealer if any of these conditions exist. of Your dealer will know the kind wheel you need. Each new wheel should have the same load carrying capacity, diameter, width, offset, andbe mounted the same wayas the one it replaces. 6-47