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Wheels
Uniform tire quality grading
- Tread wear
- Traction AA A B C
- Temperature
ABC
Quality grades can be found where applicable on
the tire side wall between tread shoulder and
maximum section width
c::>
page 207, fig. 167.
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 (11/2) 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
c::>
.&. .
224
The grade C corresponds to a level of perform-
ance which all passenger car tires must meet un-
der the Federal Motor Veh icle Safety Standard
No. 109 . Grades Band A represent higher levels
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
Appli es to : vehicles wit h tire pressure mo nitori ng 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 monitoring 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 ""
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