1997 GMC Jimmy Owner's Manual - Page 305

Traction -- A, B, C The tmction grades, from highest to lowest. are A, B. and C, and they represent the tire's ability to stop on wet pavement as measured under controlled conditions on specified government test surfaces asphalt and concrete. of A tire marked C may have poor tractionperf'ormance. Wxning: The traction grade assigned to this tire is based on braking (straight ahead) traction tests and does not include cornering (tuning) traction. Warnin?: Thc ten~perat~u-e pxde this tire is for estnblishcd for a tire that is properly intlated and not overloaded. Excessive speed. underinflation,or excessive loading. either separatcly or i n combination. c;m c a ~ ~heat buildup md possible tire failure. se Wheel Alignment and Tire Balance The wheels on your vehicle were aligned and balanced care1'uIly at the factory to give you the longest tire life and best overdl performance. Temperature -- A, B, C The temperature gradesare A (,thehighest), B, and C. representing the tire's resistance t o the gencration of heat and its ability to dissipate heat when tested undcr controlled conditions o n a specified indoor laboratory test wheel. Sustained high temperature can cause the material of the tire to degenerate and reducetire life, and excessive temperature canlead to sudden tire failure. The gradeC corresponds t o a level of performance which all passenger car tires must meet under the Federal Motor Vehicle Safety Standard No. 109. Grades B and A represent higher levels of performance on the laboratory test wheel than the minimum required by law. lee1 Replacement ~ e p l ;my e ~ wheel that is bent. cracked, or badly rusted 01- corrocled. I f wheel n ~ ~keep coming loose. the wheel, ts wheel bolts and wheel nuts should be 1-eplacec1.If the wheel leaks air, replace it (except some aluminum wheels. which c m sometimes be repaired). See your G M dcalcr if a n y o f ' these conditions exist. 6-46