1998 Chevrolet Express Van Owner's Manual - Page 287

-action -- A, B, C The traction grades, from highest to lowest, are A, B, and C, and they represent the tire's ability stop on to wet pavementas measured undercontrolled conditions on specified government testsurfaces of asphalt and concrete. A tire marked C may have poor traction performance. Warning: The traction grade assigned to this tire is based on braking (straight ahead) traction tests and does not include cornering(turning) traction. 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. 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 separatelyor in combination, tire can cause heat buildup and possible failure. Temperature -- A, B, C Wheel Alignment ant 'e Balance The temperature grades are A (the highest), B, and C, representing the tire'sresistance to the generation of heat and its abilityto dissipate heat when tested under controlled conditions on a specified indoor laboratory test wheel. Sustainedhigh temperature can cause the material of thetire to degenerate and reducetire life, and excessive temperature can lead to sudden tire failure. The grade C corresponds to a level of performance which all passenger tires must meet car The wheels on your vehicle werealigned and balanced carefully at the factory to give you the longesttire life and best overall performance. Scheduled wheel alignment and wheel balancing are not needed. However,if you notice unusual tire wear or your vehicle pullingone way or the other, the alignment may needto be reset. If you notice your vehicle vibrating whendriving on a smooth road, your wheels may need be rebalanced. to 6-48