Subaru 2013 Impreza - Manual (Page 447)

Black plate (467,1)
北米Model "A1140BE-A" EDITED: 2012/ 6/ 20
Uniform tire quality grading
standards
This information indicates the rela-
tive performance of passenger car
tires in the area of treadwear,
traction, and temperature resis-
tance. This is to aid the consumer
in making an informed choice in the
purchase of tires.
Quality grades can be found where
applicable on the tire sidewall be-
tween tread shoulder and maxi-
mum section width. For example:
Treadwear 200 Traction AA Tem-
perature A
The quality grades apply to new
pneumatic tires for use on passen-
ger cars. However, they do not
apply to deep tread, winter type
snow tires, space-saver or tempor-
ary use spare tires, tires with
nominal rim diameters of 12 inches
or less, or to some limited produc-
tion tires.
All passenger car tires must con-
form to Federal Safety Require-
ments in addition to these grades.
& Treadwear
The treadwear grade is a compara-
tive rating based on the wear rate of
the tire when tested under con-
trolled conditions on a specified
government 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 AA, A, B, C
The traction grades, from highest to
lowest, are AA, A, B and C. Those
grades represent the tire
’s ability to
stop on wet pavement as measured
under controlled conditions on spe-
cified government test surfaces of
asphalt and concrete. A tire marked
C may have poor traction perfor-
mance.
WARNING
The traction grade assigned to
this tire is based on straight-
ahead braking traction tests,
and does not include accel-
eration, cornering, hydroplan-
ing, or peak traction charac-
teristics.
& Temperature A, B, C
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 con-
ditions on a specified indoor labora-
tory test wheel. Sustained high
temperature can cause the material
of the tire to degenerate and reduce
tire life, and excessive temperature
can lead to sudden tire failure. The
Consumer information and Reporting safety defects
13-15
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