1994 Buick Regal Owner's Manual - Page 242

Treadwear The treadwear grade is a comparative rating based on the wear rate of the tire when tested under controlled conditiolis 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 a tire graded 100. The relative performance of 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. Uniform Tire Quality Grading The following infortnation relates to the system developed by the United States National Highway Traffic Safety Administration which grades tires by tfeadwear, traction and temperature performance. (This applies only to vehicles sold in the United States.) Traction A, B, C The traction grades, ffom highest to lowest are: A, B, and C. They represent the tire's ability to stop on .wet pavement as measured under controlledconditions on specified governmenttest surfaces of asphalt and concrete. A tire marked C may have poortraction performance. Warning: The traction grade assigned to this tire .is based on braking (straight-ahead) traction tests and does not include cornering (turning) traction. - 240