1993 Oldsmobile Bravada Owner's Manual - Page 239

F IUni$om Tire Quality 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. I - 7 L The temperature gradesare A (the highest), B, and C, representing the tire's resistance tothe generation of heat and its ability to dissipate heat when tested under controlled conditions ona specified indoor laboratory test wheel. Sustained high temperature can cause Traction-A, 6, C the material of the tire to degenerate and The traction grades, from highest to reduce tire life, and excessive lowest are: A, B, and C. They represent temperature can lead to sudden tire Treadwear the tire's ability to stop on wet pavement failure. The grade C corresponds to a The treadwear grade is a comparative as measured under controlled conditions level of performance which all rating based on the wear rate the tire of on specified government test surfacesof passenger car tires must meet under the when tested under controlled conditions asphalt and concrete.A tire marked C Federal Motor Vehicle Safety Standard on a specified government test course. may have poor traction performance. No. 109. Grades B and A represent For example, a tire graded 1 0 would 5 Warning: The traction grade assigned higher levels of performance on the wear one and a half (1Y2) times as well to this tire is based on braking (straight- laboratory test wheel than the minimum on the government course as a tire required by law. graded 100. The relative performance of ahead) traction tests and does not include cornering (turning)traction. tires depends upon the actual conditions The following information relates to the system developed by the United States National Highway Traffic Safety Administration which grades tiresby treadwear, traction and temperature performance. (Th.ls applies only to vehicles sold in the United States.) Grading Temperature-A, 6, C 237 L