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Maintenance
3. Checking tire life (TIN : TireIdentification Number)
Any tires that are over 6 years old,
based on the manufacturing date,
(including the spare tire) should be
replaced by new ones. You can find
the manufacturing date on the tire
sidewall (possibly on the inside of the
wheel), displaying the DOT Code.
The DOT Code is a series of num-
bers on a tire consisting of numbers
and English letters. The manufactur-
ing date is designated by the last four
digits (characters) of the DOT code.
DOT : XXXX XXXX OOOO
The front part of the DOT means a
plant code number, tire size and
tread pattern and the last four num-
bers indicate week and year manu-
factured.
For example:
DOT XXXX XXXX 1618 represents
that the tire was produced in the 16th
week of 2018.
4. Tire ply composition and mate-rial
The number of layers or plies of rub-
ber-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 con-
struction; the letter "D" means diago-
nal or bias ply construction; and the
letter "B" means belted-bias ply con-
struction.
5. Maximum permissible inflationpressure
This number is the greatest amount of
air pressure that should be put in the
tire. Do not exceed the maximum per-
missible 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 maxi-
mum section width.
For example:
TREADWEAR 440
TRACTION A
TEMPERATURE A
WARNING - Tire age
Replace tires within the recom-
mended time frame. Failure to
replace tires as recommended
can result in sudden tire failure,
which could lead to a loss of
control and an accident.
Maintenance
46
7
Tread wear
The tread wear grade is a compara-
tive rating based on the wear rate of
the tire when tested under controlled
conditions on a specified govern-
ment test course. For example, a tire
graded 150 would wear one-and-a-
half times (1½) as well on the gov-
ernment 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. Tires degrade over time, even when
they are not being used. Regardless
of the remaining tread, we recom-
mend that tires be replaced after
approximately six (6) years of normal
service. Heat caused by hot climates
or frequent high loading conditions
can accelerate the aging process.
These grades are molded on the
side-walls of passenger vehicle tires.
The tires available as standard or
optional equipment on your vehicles
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 tires ability to
stop on wet pavement as measured
under controlled conditions on spec-
ified government test surfaces of
asphalt and concrete. A tire marked
C may have poor traction perform-
ance.
The traction grade assigned to this
tire is based on straight-ahead brak-
ing traction tests, and does not
include acceleration, cornering,
hydroplaning, or peak traction char-
acteristics.
