1993 Buick LeSabre Owner's Manual - Page 261
1993 Buick LeSabre Manual
Page 261 highlights
A CAUTION: ; I Mixing tires could cause you to lose control while driving. If you mix tires of different sizes or types (radial and bias-belted tires), the vehicle may not handle properly, and you could have a crash. Be sure to use the same size and type tires on all four wheels. It's all right to drive with your compact spare, though. It was developed for use on your vehicle. graded 100. The relative performanceof tires depends upon the actual conditionsof their use, however, and may depart significantly from the norm due to variations in driving habits, servicepractices 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 thetire's ability to stop on wet pavement as measured under controlled conditions on specified government test surfaces of asphalt and concrete. A tire marked C may have poor traction performance. Warning: The traction grade assignedto this tireis based on braking (straight-ahead)traction tests and does not include cornering (turning) traction. - I Uniform Tire Quality Grading The following information relates to the system developed by the United States NationalHighway Traffic Safety Administrationwhich grades tires by treadwear, traction and temperature performance. (This applies only tovehicles sold in the United States.) Temperature - A, B, C The temperature grades areA (the highest), B, and C, representing thetire's resistance to the generation of heat and its ability to dissipateheat when tested under controlled conditions on a specified indoor laboratory test wheel. Sustained high temperature can cause the material of the tire to degenerate and reduce tire and life, excessive temperature can lead to sudden tire failure. The gradeC corresponds to a level of performance Treadwear The treadwear gradeis a comparative rating based on the wear rate of the tire when tested under controlled conditions on a specified government test course. For example, a tire graded 150 would wear one and a half (1 1/2) times as well on the government course as tire a