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4-36
Winter Driving
Here are some tips for winter driving:
Have your vehicle in good shape for winter.
You may want to put winter emergency supplies in
your vehicle.Include an ice scraper, a small brush or broom, a supply
of windshield washer fluid, a rag, some winter outer
clothing, a small shovel, a flashlight, a red cloth and
reflective warning triangles. And, if you will be driving
under severe conditions, include a small bag of sand, a
piece of old carpet or a couple of burlap bags to help
provide traction. Be sure you properly secure these
items in your vehicle.
Driving on Snow or Ice
Most of the time, those places where your tires meet the
road probably have good traction.
However, if there is snow or ice between your tires and
the road, you can have a very slippery situation. You'll
have a lot less traction or ªgripº and will need to be
very careful.
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6-48 Uniform Tire Quality Grading
The following information relates to the system developed
by the United States National Highway Traffic Safety
Administration, which grades tires by treadwear, traction
and temperature performance. (This applies only to
vehicles sold in the United States.) The grades are molded
on the sidewalls of most passenger car tires. The Uniform
Tire Quality Grading system does not apply to deep tread,
winter
-type snow tires, space-saver or temporary use spare
tires, tires with nominal rim diameters of 10 to 12 inches
(25 to 30 cm), or to some limited
-production tires.
While the tires available on General Motors passenger
cars and light trucks may vary with respect to these
grades, they must also conform to Federal safety
requirements and additional General Motors Tire
Performance Criteria (TPC) standards.
Treadwear
The treadwear 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 a 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 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 specified government test surfaces of
asphalt and concrete. A tire marked C may have poor
traction performance. 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.
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 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
temperature 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 B and A represent higher levels
of performance on the laboratory test wheel than the
minimum required by law.
