Toyota 4Runner 1997, Operation Manual

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This information has been prepared in ac-
cordance with regulations issued by the
National Highway Traffic Safety Adminis-
tration of the U.S. Department of Trans-
portation. It provides the purchasers and/
or prospective purchasers of Toyota
vehicles with information on uniform tire
quality grading.
Your Toyota dealer will help answer any
questions you may have as you read this
information.
DOT quality grades—All passenger
vehicle tires must conform to Federal
Safety Requirements in addition to
these grades. These quality grades are
molded on the sidewall.
Treadwear—The treadwear grade is a
comparative rating based on the wear
rate of the tire when tested under con-
trolled conditions on a specified govern-
ment 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,
and they represent the tire’s ability to stop
on wet pavement as measured under
controlled conditions on specified govern-
ment test surfaces of asphalt and con-
crete. A tire marked C may have poor trac-
tion performance.
Warning: The traction grade assigned to
this tire is based on braking (straight
ahead) traction tests and does not include
cornering (turning) traction.
Temperature A, B, C—The temperature
grades are A (the highest), B, and C, rep-
resenting the tire’s resistance to the gen-
eration of heat and its ability to dissipate
heat when tested under controlled condi-
tions on a specific indoor laboratory test
wheel. Sustained high temperature can
cause the material of the tire life, and ex-
cessive temperature can lead to sudden
tire failure. The grade C corresponds to a
level of performance which all passenger
car tires must meet under the Federal Mo-
tor Vehicle Safety Standard No. 109.
Grades B and A represent higher levels of
performance on the laboratory test wheel
than the minimum required by law. Warning: The temperature grades for this
tire are established for a tire that is proper-
ly inflated and not overloaded. Excessive
speed, underinflation, or excessive load-
ing, wither separately or in combination,
can cause heat buildup and possible tire
failure.
Uniform tire quality grading