1993 Cadillac Eldorado Owner's Manual - Page 325

Treadwear The treadwear grade a comparative rating is based on thewear rate of the tire when tested under controlled conditions on a specified 150 government test course. For example, a tire graded would wear one and a half (1 1/2) times as well on the government course as a tire graded 100. The relative performanceof tires depends upon the actual conditions of their use, however, and may depart significantly from the norm due to variations in driving habits, service practices and differences in road characteristics and climate. Traction A, B, C The traction grades, from highest to lowest are: A, B, and C. They represent the tire's ability to stop on pavement as measuredunder wet controlled conditionson specified government test surfaces 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. - Temperature - A, B, C The temperature grades areA (the highest), B, and C, representing the tire's resistance to the generation of heat and its ability to dissipate heat on when tested under controlled conditions a specified indoor laboratory test wheel. Sustained high temperature can cause the material the tire of to degenerate and reduce tire and excessive temperature can lead to life, sudden tire failure. The grade corresponds to alevel of performance C which all passenger car tires must meet under theFederal 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 tire is established for a tire that this is properly inflated and not overloaded.Excessive speed, underinflation, or excessive loading, either separately orin combination, can cause heat buildup and possible tire failure. Those grades are molded on the sidewalls of passenger car tires. 31 I