8
CONSUMER INFORMATION & REPORTING SAFETY DEFECTS
7
o Four numbers represent the week
and year the tire was built. For
example, the numbers 3105 means
the 31st week of 2005.
4. Tire ply composition and material
The number of layers or plies of
rubbercoated fabric in the tire. Tire
manufacturers also must indicate
the materials in the tire, which in-
clude 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 pres-
sure.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
(UTQG):
Tire manufacturers are required to
grade tires based on three perfor-
mance factors: treadwear, traction
and temperature resistance. For more
information, see Uniform Tire Qual-
ity Grading on page 8-14.
I030D01JM-AATTIRE TERMINOLOGY AND DEFINI-
TIONS
Air Pressure: The amount of air inside
the tire pressing outward on the tire. Air
pressure is expressed in pounds per
square inch (psi) or kilopascal (kPa).
Accessory Weight: This means the
combined weight of optional accesso-
ries. Some examples of optional ac-
cessories are, automatic transmission,
power seats, and air conditioning.
Aspect Ratio: The relationship of a
tire's height to its width.
Belt: A rubber coated layer of cords that
is located between the plies and the
tread. Cords may be made from steel or
other reinforcing materials.
Bead: The tire bead contains steel
wires wrapped by steel cords that hold
the tire onto the rim.
Bias Ply Tire: A pneumatic tire in which
the plies are laid at alternate angles
less than 90 degrees to the centerline of
the tread.
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