How to Determine the Age of Your Tires

The first step in determining the age of your tires is to read our article on DOT Tire Identification Number. Although the DOT number is commonly (but mistakenly) referred to as a product serial code, the DOT number is actually a code that identifies the manufacturing batch. The DOT number also contains information about the week, year, and location where the tire was manufactured.

The U.S. Department of Transportation (DOT) National Highway Traffic Safety Administration (NHTSA) requires the DOT number to be banded on the tire's sidewall. This number begins with the letters "DOT" and is followed by a series of 10-12 characters. The additional characters identify the manufacturing location, the tire size, the manufacturer's code, and the week and year the tire was manufactured. Therefore, it is easy to determine the age of the tire by looking at the DOT code.

If your tires were manufactured before the year 2000, the date of manufacture will be the last 3 digits of the DOT code. This is because tires were assumed to have a life of ten years or less, so the last digit is actually the year within the current decade. The first two digits refer to the week within that year. For example, if the last 3 digits were "022", it would mean that the tire was manufactured in the second week of the year, and the year is the second year of the decade. In this example, the tire could have been manufactured in 1982 or 1992. While there is no universal identifier used to signify which decade, some tires have a small triangle following the DOT code to indicate the 1990's.

Beginning in the year 2000, all tires manufactured have had a 4-digit code which uses 2 digits for the year and 2 digits for the week of the year during which the tire was manufactured. For example, if the last four digits of the DOT code were "0203", it would signify that the tire was manufactured during the second week of the year 2003.

If you look at the tire's sidewall and see a DOT number that appears to be incomplete, that is because the current regulations require the entire DOT number to be branded on only one sidewall, while the opposite sidewall is branded with just the first few digits. To see the entire DOT number, simply look on the other sidewall.

There is one other way to determine the age of your tires - by keeping your sales receipt! It's a good idea to hang on to your sales receipt in case you have a warranty claim for the tire(s). Most warranties from tire manufacturers cover the tires for four years from the date of purchase, or five years from the week that the tires were manufactured. If you lose your sales receipt, you could actually limit your warranty coverage. For example, if you purchased new tires today that were manufactured two years ago, your warranty would last for 4 years from today's date since that is the date of purchase. However, if you lost your sales receipt, then the tires would be covered for five years from the date of manufacture, which was two years ago. Therefore, your warranty would end three years from now, not four, meaning you would lose a year of coverage.