Wheels
- Traction AA A B C
- T emperature ABC
Quality grades can be found where appl icable on
the tire side wall between tread shoulder and
maximum section width
~ page 206, fig. 187.
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 contro lled conditions on a specified gov
ernment test course.
F or examp le, 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 actua l conditions of their use, however, and
may depart significantly from the norm due to
variations in driving habits, service practices and
d ifferences in road characteristics and climate.
Traction
The traction grades, from highest to lowest, are
AA, A, Band
C. T hose grades represent the tire's
abi lity 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 d iss ipate
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 excess ive temperature can lead to sudden
tire
fa ilure ~.&. .
The grade C corresponds to a level of perform
ance which a ll passenger car tires must meet un-
222
der the Federal Motor Vehicle 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 tract ion grade assigned to this t ire 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 tha t 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
proper ly inflated and not over or underinflat
ed.
Tire pressure monitoring system
ill General notes
Each tire, including the spare (if prov ided),
shou ld 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 veh icle has
t ir es of a diffe rent size t han the size ind icated on
the vehicl e placard or tire infl ation press ure la
bel, you sho uld determine the proper tire infla
tion pressure for those tires).
As an added safety featu re, you r vehicle has been
equipped with a tire pressure monitoring system
(TPMS) that illuminates a low tire pressure tell
ta le when one or more of your tires is significant
l y under-inflated. According ly, w hen the low tire
pressure telltale illuminates, you should stop and
check your t ires as soon as possible, and inflate
them to the proper pressure. Dr iving on a
.,..
