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Example tire size designation:
(These numbers are provided as
an example only; your tire size
designator could vary depending on
your vehicle.)
235/55R19 105W
235 - Tire width in millimeters.
55 - Aspect ratio. The tire’s section
height as a percentage of its
width.
R - Tire construction code (Radial).
19 - Rim diameter in inches.
105 - Load Index, a numerical code
associated with the maximum
load the tire can carry.
W - Speed Rating Symbol. See
the speed rating chart in
this section for additional
information.
Wheel size designation
Wheels are also marked with
important information that you need
if you ever have to replace one. The
following explains what the letters
and numbers in the wheel size
designation mean.
Example wheel size designation:
7.5J X 19
7.5 - Rim width in inches.
J - Rim contour designation.
19 - Rim diameter in inches.
Tire speed ratings
The chart below lists many of the
different speed ratings currently
being used for passenger vehicle
tires. The speed rating is part of the
tire size designation on the sidewall
of the tire. This symbol corresponds
to that tire’s designed maximum safe
operating speed.
Speed Rating
SymbolMaximum Speed
S 112 mph (180 km/h)
T 118 mph (190 km/h)
H 130 mph (210 km/h)
V 149 mph (240 km/h)
W 168 mph (270 km/h)
Y 186 mph (300 km/h)
3. Checking tire life (TIN : Tire
Identification Number)
Any tires that are over six 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 numbers
on a tire consisting of numbers and
English letters. The manufacturing
date is designated by the last four
digits (characters) of the DOT code.
DOT : XXXX XXXX OOOO
The front part of the DOT shows a
plant code number, tire size and
tread pattern and the last four
numbers indicate week and year
manufactured.
For example:
DOT XXXX XXXX 1522 represents that
the tire was produced in the 15th
week of 2022.
