1996 Pontiac Grand Am Owner's Manual - Page 264

car which all passenger tires must meet under the Traction A, B, C No. Federal Motor Vehicle Safety Standard 109. Grades The traction grades, from highest to lowest, are B, A, €3 and A represent higher levels performance on the of and C, and they represent the tire's ability to stop on wetlaboratory test wheel than minimum required by law. the pavement as measured under controlled conditions on Warning: The temperaturegade for this tire is specified government test surfaces asphalt and of established for a tire thatproperly inflated and not is concrete. A tire markedC may have poor traction overloaded. Excessive speed, underinflation, or performance. in excessive loading, either separately or combination, Warning: The traction grade assigned to this is based tire can cause heat buildup and possible tire failure. and on braking'(straightahead) traction tests does not include cornering (turning) traction. Wheel Alignment and Tire Balance Temperature A, B, C - carefully at the factory to give you the lo'ngest tire life The temperature grades areA (the highest),B, and C, and best overall performance. representing the tire's resistance to the generation of heat and its ability to dissipate heat when tested underIn most cases, you..will not need to have your wheels if wear aligned again. However, you notice unusual tire controlled conditions on a specified indoor laboratory or your vehicle pulling one way or the other, the can test wheel. Sustained high temperature cause the If material of the tire to degenerate and reduce tire life, and alignment may need to be reset. you notice your driving on a smooth road, your vehicle vibrating when excessive temperature can lead to sudden tire failure. wheels may needto be rebalanced. af The gradeC corresponds to a level performance - The wheels osn your vehicle were aligned and balanced