12-2For U.S.A.
The following information has b een c omp iled ac c ord i
ng to Cod e of Fed -
eral Reg ulations “Title 49, Part 575 ”.
Uniform tire quality grading standards
This information ind ic ates the relative p erformanc e of p asseng er c ar tires
in the area of tread wear, trac tion, and temp erature resistanc e. This is to
aid the c onsumer in making an informed c hoic e in th e p urc hase of tires.
These g rad es are mold ed in the sid ewall of the tire and c an b e inter-
p reted b y referring to the following information: Treadwear
The tread wear g rad e is a c omp arative rating b ased o n the wear rate of
the tire when tested und er c ontrolled c ond itions on a sp ec ified g overn-
ment test c ourse.
For examp le, a tire g rad ed 150 would wear one and o ne-half (1-1/2)
times as well on the g overnment c ourse as a tire g r ad ed 100. The rela-
tive p erformanc e of tires d ep end s up on the ac tual c ond itions of their
use, however, and may d ep art sig nific antly from the norm d ue to varia-
tions in d riving hab its, servic e p rac tic es and d iff erenc es in road c harac -
teristic s and c limate. Traction A, B, C
The trac tion g rad es, from hig hest to lowest, are A, B and C, and they
rep resent a tire ’s ab ility to stop on wet p avement as measured und er
c ontrolled c ond itions on sp ec ified g overnment test surfac es of asp halt
and c onc rete. A tire marked C may have p oor trac tio n p erformanc e.
WARN IN G
The traction grade assigned to a tire is based on braking (straigh- tahead) traction tests and does not include cornering (turning)traction.
Consumer information and Reporting safety defects12-3
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CONTINUED –
Temperature A, B, C
The temp erature g rad es are A (hig hest), B and C, re p resenting the tire’s
resistanc e to g eneration of heat and its ab ility to d issip ate heat when
tested und er c ontrolled c ond itions on a sp ec ified i nd oor lab oratory test
wheel. Sustained hig h temp erature c an c ause the mat erial of the tire to
d eg enerate and red uc e tire life, and exc essive temp erature c an lead to
sud d en tire failure. Grad e C c orresp ond s to a level of p erformanc e
whic h all p asseng er c ar tires must meet und er the F ed eral Motor Vehic le
Safety Stand ard s No. 109. Grad es B and A rep resent hig her levels of
p erformanc e on the lab oratory test wheel than the m inimum req uired b y
law.
WARNING
The temperature grade for a tire is established for one that is
properly inflated and not overloaded. Excessive speed, under
inflation or excessive loading, either separately or in combina-tion, can cause heat buildup and possible tire failure.
