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Tires and wheels
P'tr:1-------------------
Quality grades can be found where applicable on the tire side wall
between tread
shoulder and
maximum
section width
=>
page 248,
fig. 153.
For example: Tread
wear
200, Traction AA,
Temperature
A.
All passenger car
tires must
conform
to
Federal
Safety
Require-
ments 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
government test course
.
For example, a
tire
graded
150
would wear
one
and one half (1
1/2)
times as well on the government course as a tire graded
100.
The
relative
performance of tires depends upon the actual condi
-
tions of
their use, however, and
may
depart significantly
from the
norm due to variations in driving habits, service practices and differ
-
ences 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 under controlled
conditions
on specified government
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 dissi
-
pate
heat
when tested under controlled conditions
on
a specified
indoor
laboratory
test wheel.
Sustained
high temperature
can cause
the
material
of the
tire
to
degenerate and reduce
tire
life, and excessive
temp
erature
can lead
to sudden tire failure
=>&
.
The grade C
corresponds to
a
level of
performance which all
passenger car tires must meet under 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.
&
WARNING
The traction grade assigned to this tire is based on straight-ahead
braking traction tests, and does not include acceleration,
cornering, hydroplaning or peak traction
characteristics.
&
WARNING
The temperature grade for this tire is established 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.
•
Winter tires
Winter tires can improve
vehicle handling
on
snow
and
ice. At temperatures below 45
°F (7 °C)
we recommend
changing to winter tires.
In
some heavy snow areas, local governments may require true
winter or "snow"
tires, those
with very deeply cut
tread. These
tires
should only be used in pairs and be installed on all four wheels.
Make
sure you
purchase
snow tires that are the same size and
construction
type
as the other
tires
on your vehicle.
If
your vehicle is equipped with all-wheel drive
*
,
this
will
improv
e
traction during
winter
driving,
even with the standard
tires.
However,
we strongly recommend that you always equip all four
wheels
on your vehicle
with
correctly fitted winter
tires or
all -season
tires, when winter road conditions are expected.
This
also improves
the
vehicle's braking
performance
and reduces stopping
distances
.
Summer
tires
provide
less
grip on
ice
and snow.
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