Wheels
Quality grades can be found where applicable on
the tire side wall between tread shoulder and maximum section width
¢ page 191, fig. 156.
For example: Tread wear 200, Traction AA, Tem
perature
A.
All passenger car tires must conform to Federal
Safety Requirements in addition to these grades.
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 gov
ernment test course.
For example, a tire graded 150 would wear one
and one half (1 1/2) times as well on the govern
ment 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
The traction grades, from highest to lowest, are
AA, A, Band
C. Those grades represent the tire 's
ability to stop on wet pavement as measured un
der controlled conditions on specified govern ment test surfaces of asphalt and concrete. A tire
marked C may have poor traction performance
¢&_ .
Temperature
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 mate rial of the tire to degenerate and reduce tire life,
and excessive temperature can lead to sudden
tire failure ¢&. .
The grade C corresponds to a level of perform
ance which all passenger car tires must meet un
der the Federal Motor Vehicle Safety Standard
No. 109 . Grades Band A represent higher levels
208
of performance on the laboratory test wheel than
the minimum required by law.
A WARNING -
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration, cor nering, hydroplaning or peak traction charac
teristics .
A WARNING
The temperature grade for this tire is estab
lished for a tire that is properly inflated and
not overloaded. Excessive speed, underinfla
tion, or excessive loading, either separately or
in combination, can cause heat buildup and
possible tire failure.
A WARNING
Temperature grades apply to tires that are properly inflated and not over or underinflat
ed.
Tire pressure monitoring system
(l) General notes
Appl ies to vehicles: with tire pressure mon itoring system
-
Each tire, including the spare (if provided),
should be checked monthly when cold and inflat
ed to the inflation pressure recommended by the
vehicle manufacturer on the vehicle placard or
tire inflation pressure label. (If your vehicle has
tires of a different size than the size indicated on
the vehicle placard or tire inflation pressure la
bel, you should determine the proper tire infla
tion pressure for those tires).
As an added safety feature, your vehicle has been
equipped with a tire pressure monitor ing system
(TPMS) that illuminates a low tire pressure tell
tale when one or more of your tires is significant-
ly under-inflated. Accordingly, when the low tire
pressure telltale illuminates, you should stop and
check your tires as soon as possible, and inflate
them to the proper pressure . Driving on a signifi
cantly under-inflated tire causes the tire to over
heat and can lead to tire failure . Under-inflation ..,.
