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Wheels
Qua lity grades can be found where applicable on
the tire side wall between t read sho ulder and
maximum sect ion w idth
c::>
page 209,
fig.
179.
For example:
Tread wear
200
,
Tract ion
AA,
Tem-
peratu re
A.
All passenger ca
r
tires must confo rm to Federal
Safety Requiremen
t
s in add it ion to
t
hese grades.
Tread wear
The
tread wear
grade is a comparative rating
based on the wear rate of the tire when tested
unde
r
controlled conditions on a spec ified gov-
ernment
t
est course.
For examp le, a t ire graded 150 would wear one
and one half
(1
1/2) t imes as well on the govern-
ment course as a tire graded 100
.
The relat ive performance of t ires depends upon
the actua
l
conditions of their use, however, and
may depart significantly from the norm due to
variations
in
driving hab its, service practices and
d iffe rences
in
road character istics and clima te.
Traction
The
traction
grades, from highest to lowest, are
AA,
A,
Band C. Those grades represent the tire's
ab ility to stop on wet pavement as measu red un-
de
r
controlled cond it ions on spec ified govern-
ment test su rfaces of asphalt and concrete. A
tir
e
marked C may have poor
t
raction performance
c::>
&
_.
Temperature
The
temperature
grades are A (the highest), B,
a nd C, rep resent ing t he tire's res istance to the
genera
t
ion of heat and its a bility
t
o dis sipate
heat w hen tested unde
r
controlled cond itions on
a specified indoo
r
laboratory test whee
l.
Sustained high temperature
can cause the mate-
rial of
t
he tire to degenerate and red uce tire life,
a
nd excessive
t
empera
tur
e can lead to sudden
tire failure
c::>
&..
The grade C corresponds to a level of perform-
ance wh ich a
ll
passenge
r
ca
r
tires m ust meet un-
de
r
t he Federal Motor Vehicle Safety
St
andard
No. 109. Grades Band A represent higher levels
226
of pe rformance on the laboratory test whee
l
than
the minimum required by
law.
A
WARNING
-
The t raction grade assigned to th is tire is
based on straight-ahead
braking tract ion
tests, and does not include acce lerat ion, cor-
nering, hyd roplaning or peak traction charac-
teristics.
A
WARNING
The temperature
g rade for th is tire is estab-
lished for a tire that is properly inf lated and
not ove rloaded. Excess ive speed, underi nfla-
tion, o
r
excess ive loadi ng, eithe
r
separately or
in
comb inat io n, can cause heat bu ild up and
possible tire failure.
A
WARNING
Tempe ratu re grades apply to ti res that are
properly inflated and not over or underinflat-
ed.
Tire pressure
monitoring
system
(l)
General notes
Appli
es
t
o vehicl es: wi
th t
ire pressure mo nito
rin
g system
-
Each tire, incl uding the spare (if provided),
sho uld be checked monthly when cold and inflat-
ed to the inflat ion pressure recommended
by the
vehicle manufacturer on the vehicle placard or
tire inflat ion pressure label. (If your vehicle has
tires of a different s ize than the size indicated on
the ve hicle placard or t ire inflation pressu re la-
bel, you should dete rm ine the proper t ire infla-
tion pressu re for those t ires).
As a
n
added safety feature, your ve hicle has been
equipped with a tire pressure mon itor ing system
(TPMS) that illum inates a low t ire pressure te ll-
ta le w hen o ne or mo re of your
ti
res is sign ificant
-
ly unde r-inflated. According ly, w hen t he low t ire
pressure te lltale illuminates, you shou ld stop and
check your tires as soon as possible, and inflate
them to the proper pressure
.
Driving on a signifi-
cant ly under-inf lated tire causes the t ire to over-
heat and can lead to tire failure. Under-inflation
.,,.
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