Maintenance38 7Tire speed ratings The chart below lists many of the dif-
ferent speed ratings currently being
used for passenger cars. The speed
rating is part of the tire size designa-
tion on the sidewall of the tire. This
symbol corresponds to that tire's
designed maximum safe operating
speed.
G201003AEN3. Checking tire life (TIN : Tire
Identification Number) Any tires that are over 6 years, based
on the manufacturing date, tire
strength and performance, decline
with age naturally (even unused
spare tires). Therefore, the tires
(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 1606 represents
that the tire was produced in the 16th
week of 2006.
G201004AUN4. Tire ply composition and materialThe number of layers or plies of rub-
ber-coated fabric are 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.
WARNING - Tire age
Tires degrade over time, even
when they are not being used.
Regardless of the remaining
tread, it is recommended that
tires generally be replaced after
six (6) years of normal service.
Heat caused by hot climates or
frequent high loading conditions
can accelerate the aging
process. Failure to follow this
warning can result in sudden tire
failure, which could lead to a
loss of control and an accident
involving serious injury or death.
S 180 km/h (112 mph)
T 190 km/h (118 mph)
H 210 km/h (130 mph)
V 240 km/h (149 mph)
Z Above 240 km/h (149 mph)
Maximum Speed Speed
Rating
Symbol
