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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.)
245/45R19 101H
245 - Tire width in millimeters.
45 - Aspect ratio. The tire’s section 
height as a percentage of its width.
R - Tire construction code (Radial).
19 - Rim diameter in inches.
101 - Load Index, a numerical code 
associated with the maximum load 
the tire can carry.
H - 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:
8.5J X 19
8.5 - 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 
Symbol
Maximum Speed
S 180 km/h (112 mph)
T 190 km/h (118 mph)
H 210 km/h (130 mph)
V 240 km/h (149 mph)
W 270 km/h (168 mph)
Y 300 km/h (186 mph)
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 3223 represents that the 
tire was produced in the 32nd week of 
2023.