When towing a trailer, change oil in the
transmission more frequently. See the
Maintenance Schedule.DOT Quality Grades: All passenger car tires
must conform to Federal Safety Require-
ments in addition to these grades.
Treadwear
Treadwear grade is a comparative rating
based on tire wear rate when tested under
controlled conditions on specified govern-
ment test courses. 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. However,
relative tire performance depends on actual
driving conditions, and may vary signifi-
cantly from the norm due to variations in
driving habits, service practices and differ-
ences in road characteristics and climate.
Traction A, B and C
Traction grades are A (the highest), B and
C. They represent a tire's ability to stop on
wet pavement as measured under con-
trolled conditions, on specified government
test surfaces of asphalt and concrete. A tire
marked with a C may have poor traction
performance.
WARNING
The traction grade assigned to your
vehicle tires is based on straight line
braking traction tests and does not
include cornering (turning) traction.
Temperature A, B and C
Temperature grades are A (the highest), B,
and C. They represent a tire's resistance to
heat build-up, and its ability to dissipate
heat when tested under controlled condi-
tions on a specified indoor laboratory test
wheel. Sustained high temperature can
cause tire material to degenerate, reducing
tire life. Excessive temperatures can lead to
sudden tire failure. Grade C corresponds to
a performance level which all passenger car
tires must meet under the Federal Motor
Vehicle Safety Standard No. 109. Grades A
and B represent higher levels of perfor-
mance on laboratory test wheels than the
minimum required by law.
UNIFORM TIRE QUALITY
GRADING
9-21
ZX
