How to Read Your Tire's DOT Code

#Tire D.O.T. Codes

Understanding How to Read a Tire Sidewall

The "DOT" symbol on commercial tires certifies the tire manufacturer's compliance with the U.S. Department of Transportation (DOT) National Highway Traffic Safety Administration (NHTSA) tire safety standards. The DOT serial number is located on the inside sidewall near the rim. The letters “DOT” are followed by eight to thirteen letters and/or numbers that identify where the tire was manufactured, tire size, and the manufacturer’s code, along with the week and year the tire was manufactured.

New Tire D.O.T. Code

Where is the DOT code located on a Continental Tire?

Characters 1 & 2 = Manufacturer and Plant
Characters 3 & 4 = Tire Size Code
Characters 5, 6, & 7 = Tire Type or Model

For example, this tire was manufactured in facility A3, which is the code for Continental’s Mount Vernon, Illinois, plant. Its tire size code is 72 and the tire type is KWU. This manufacturing code allows the reader to identify similar tires produced in the same plant.

Learn more about our Mount Vernon Tire Plant.

Diagram of the D.O.T. Number tire marking on Continental Truck Tires.

All tires within the U.S.A. must display a D.O.T. Number.

Characters 4 & 5 = Week of Manufacture (01 - 53)
Characters 6 & 7 = Year of Manufacture (Last 2 Digits)
For example, this tire was manufactured in week 31 of the year 2018.
You may be wondering why there are 53 possible weeks of manufacture when there are only 52 weeks in a year. D.O.T. week numbers are calculated differently. In D.O.T. week numbers, the first full week of the calendar year is week one. Therefore, it is possible that the end of December will have "week 53".

The "DOT" symbol on commercial tires certifies the tire manufacturer's compliance with the U.S. Department of Transportation (DOT) National Highway Traffic Safety Administration (NHTSA) tire safety standards.

Retread Tire D.O.T. Code Article

Manufacturing Retread Facility
Date of Manufacturing

Characters 1 - 3 = Retread Facility

Tires that are retreaded must display the retread manufacturer's D.O.T. code on the sidewall. This is often placed in the area reserved for branding, or near the tire's original D.O.T. code. Each time a tire is retreaded, it must be branded with a new code.