Treadwear
Uniform Tire Quality Grading
The following information relates to the system
developed by the United States National Highway
Traffic Safety Administration which grades tires by
treadwear, traction and temperature performance. (This
applies only
to vehicles sold in the United States.) The
treadwear grade is 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 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.
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 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 assigned
to this tire is based
on braking (straight-ahead) traction tests and does not
include cornering (turning) traction.
242
ProCarManuals.com
