Toyota Highlander Owners Manual: Uniform tire quality grading
This information has been prepared in accordance with regulations issued by the national highway traffic safety administration of the u.S. Department of transportation.
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. Quality grades can be found where applicable on the tire sidewall between tread shoulder and maximum section width.
For example: treadwear 200 traction aa temperature a
Treadwear
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. Performance may differ significantly from the norm due to variations in driving habits, service practices and differences in road characteristics and climate.
Traction aa, a, b, c
The traction grades, from highest to lowest, are aa, a, b and c, and 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.
Temperature a, b, c
The temperature grades are a (the highest), b, and c, representing the tire’s resistance to the generation of heat and its ability to dissipate heat when tested under controlled conditions on a specified indoor laboratory test wheel.
Sustained high temperature can cause the material of the tire to degenerate and reduce tire life, and excessive temperature can lead to sudden tire failure.
Grade c corresponds to a level of performance which all passenger car tires must meet under the federal motor 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 of a tire assume that it is properly inflated and not overloaded.
Excessive speed, underinflation, or excessive loading, either separately or in combination, can cause heat buildup and possible tire failure.
Tire section names
Bead
sidewall
shoulder
tread
belt
inner liner
reinforcing rubber
carcass
rim lines
bead wires
chafer
...
Glossary of tire terminology
Tire related term
Meaning
Cold tire inflation pressure
Tire pressure when the vehicle has been
parked for three hours or more, or has not
been driven more than 1 mi ...
More about Toyota Highlander:
Child restraint systems with a top tether strap
Raise the head restraint so that
the top tether strap can easily
be passed between the head
restraint and seatback.
If your child restraint system interferes
with a head restraint and cannot
be installed properly, install the
child restraint system after removing
the head restrain ...
