ITo maintain engine braking efficiency
and electrical charging performance, do
not use fifth gear (manual transmission)
or overdrive (automatic transmission).
IAvoid holding the brake pedal down too
long or too frequently. This could cause
the brakes to overheat, resulting in re-
duced braking efficiency.
When towing a trailer, change oil in the
transmission more frequently. For addi-
tional information see the ``Maintenance''
section earlier in this manual.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, rela-
tive tire performance depends on actual
driving conditions, and may vary signifi-
cantly due to variations in driving habits,
service practices and differences in road
characteristics and climate.
Traction AA, A, B and C
The traction grades from highest to lowest
are AA, A, B, and C. Those grades repre-
sent the tire's ability to stop on wet pave-
ment as measured under controlled condi-
tions on specified government test surfaces
of asphalt and concrete. A tire marked C
may have poor traction performance.
WARNING
The traction grade assigned to your ve-
hicle tires is based on straight-ahead
braking traction tests, and does not in-
clude acceleration, cornering, hydro-
planing, or peak traction characteristics.
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
10-26Technical and consumer information
ZX