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Tread wear
The tread wear 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 times (1½) 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.
These grades are molded on the 
sidewalls of passenger vehicle tires. 
The tires available as standard or 
optional equipment on your vehicle 
may vary with respect to grade.
Traction - AA, A, B & C
The traction grades, from highest to 
lowest, are AA, A, B and C. Those 
grades 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.
 
The traction grade assigned to this 
tire is based on straight ahead 
braking traction tests, and does not 
include acceleration, cornering, 
hydroplaning, or peak traction 
characteristics.
 
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. Grades B and A 
represent higher levels of 
performance on the laboratory test 
wheel than the minimum required by 
law.
 
The temperature grade for this tire is 
established for a tire that is properly 
inflated and not overloaded. 
Excessive speed, under-inflation, 
over-inflation, or excessive loading, 
either separately or in combination, 
can cause heat build-up and possible 
sudden tire failure. This may cause 
loss of vehicle control resulting in an 
accident.
 
Tire terminology and 
definitions
Air pressure
The amount of air inside the tire 
pressing outward on the tire. Air 
pressure is expressed in pounds per 
square inch (psi) or kilopascal (kPa).
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