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4. Tire ply composition and material
The number of layers or plies of
rubber-coated fabric in the tire. Tire
manufacturers also must indicate the
materials in the tire, which include
steel, nylon, polyester, and others.
The letter “R” means radial ply
construction; the letter “D“ means
diagonal or bias ply construction;
and the letter “B” means belted-bias
ply construction.
5. Maximum permissible inflation
pressure
This number is the greatest amount
of air pressure that should be put in
the tire. Do not exceed the maximum
permissible inflation pressure. Refer
to the Tire and Loading Information
label for recommended inflation
pressure.
6. Maximum load rating
This number indicates the maximum
load in kilograms and pounds that
can be carried by the tire. When
replacing the tires on the vehicle,
always use a tire that has the same
load rating as the factory installed
tire.
7. Uniform tire quality grading
Quality grades can be found where
applicable on the tire sidewall
between tread shoulder and
maximum section width.
For example:
TREADWEAR 200
TRACTION AA
TEMPERATURE A
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-a-half times (1½) 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.
These grades are molded on the
sidewalls of passenger vehicle tires.
The tires available as standard or
optional equipment on your vehicle
may vary with respect to grade.
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.
