Key to Tire Designation Codes
Speed RatingSustained speed rating is designated by a letter code:
N 93 mph (150 km/h)
S 112 mph (180 km/h)
H 130 mph (210 km/h)
V 149 mph (240 km/h)
Z 149+ mph (240+ km/h)
Tire SizeWheel diameters are usually in inches and tire width in millimeters or a letter designation.
Tire Widthsmm letter inches
80 MH 3.00
90 MJ 3.25
100 ML 3.50
110 MM 4.00
120 MP 4.50
130 MT 5.00
140 MU 5.50
150 MV 6.00
Shoulder HeightsThe shoulder height is stated as a percentage of the tire width as in the following tire designation.
100/90V18Where the
100 is tire width in mm.
The
90 means the shoulder height is 90 mm or 90 percent of 100.
It is a
V speed rated or 149 mph.
And fits a
18 inch wheel.
D.O.T. NumberThe tire also contains a D.O.T. number. The last four digits show the year and week that the tire was manufactured. e.g., a tire stamped 3202 means the tire was made in the 32nd week of 2002. Hopefully, it will not be too difficult to tell the difference in a tire made in 1992 from one made in 2002. Tires suffer from sunlight, ozone, and aging deterioration. You should choose the newer tire when the opportunity exists.
(http://kydrives.net/photos/tire_dot_code.jpg)
Source for decoding where the tire was manufacturedThe place to see all manufacturing sites for DOT approved tires is at the following site:
http://www.harriger.com/tires.htm~~~
Tire Identification Code
The U.S. Department of Transportation (DOT) National Highway Traffic Safety Administration (NHTSA) requires that Tire Identification Code be a combination of
eleven or twelve letters and numbers that identify the manufacturing location, tire size, manufacturer's code, and week and year the tire was manufactured.
While the entire Tire Identification Code is required to be branded onto one sidewall of every tire, current rules also require the first digits of the Tire Identification Code (everything but the week and year) must also be branded onto the opposite sidewall. Therefore, it is possible to see a Tire Identification Code that appears incomplete and requires looking at the other sidewall to find the entire Tire Identification Code (the use of a partial Tire Identification Code on the one sidewall reduces the risk of injury to the mold technician that would have to install the weekly date code on the top sidewall portion of a hot tire mold).
General(1) Every tire shall have permanently moulded into or onto one of its sidewalls, a tire identification number consisting of the following groups of symbols:
(a) two symbols approved by the United States National Highway Traffic Safety Administration that identify the manufacturer of the tire;
(b) two symbols that identify the tire size;
(c) not more than four symbols that
(i) identify the owner of the brand name, if applicable, and
(ii) at the manufacturer's option, form a code for the purpose of identifying the significant characteristics of the tire; and
(d) two symbols that identify the week of manufacture of the tire and
(i) until August 31, 2000, one or two symbols that identify the year of manufacture of the tire, and
(ii) on or after September 1, 2000, two symbols that identify the year of manufacture of the tire.
(2) No person shall alter, deface or remove a tire identification number.
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For example refer to the following markings:
DOT M5H3 459X 0604.M5The first letter and number following DOT designate the tire's manufacturer and plant code.
H3The third and fourth characters denote the tire size.
459XThe fifth, sixth, seventh and eight (optional) characters identify the brand as well as other significant characteristics.
0604The final four numbers denote when the tire was produced, with the first two indicating the week, and the last number indicating the year (0604 indicates the tire was built in the 6th week of 2004).
Write down the DOT number, then go to the link below, uncheck everything except "tires" in the left column and enter the first two digits after DOT into the "DOT ID" box at the bottom of the right column.
http://www.nhtsa.dot.gov/cars/rules/manufacture/index.html (http://www.nhtsa.dot.gov/cars/rules/manufacture/index.html)