When it comes to determining the age of a tire, it is easy to identify when a tire was manufactured by reading its Tire Identification Number. Tire Identification Numbers identify the week and year that the tire was produced.

The U.S. Department of Transportation (DOT) requires that Tire Identification Numbers be a combination of the letters DOT, followed by eight to thirteen letters and/or numbers that identify the manufacturing location, tire size and manufacturer’s code, along with the week and year the tire was manufactured.

The week and year the tire was produced is shown by the last four digits of the Tire Identification Number with the 2 digits being used to identify the week immediately preceding the 2 digits used to identify the year.

In California, tires cannot be sold if they are 7 years or older since they may degrade over a long period of time. This protects the consumer from purchasing a tire that has been sitting in a warehouse shelf for more than 7 years.

An example of a Tire Identification Number format is shown below:
DOT U2LL LMLR 5107 Manufactured during the 51st week of the year
DOT U2LL LMLR 5107 Manufactured during 2007