DOT (Department of Transportation)

The DOT abbreviation on your tires means that the tire meets all applicable safety standards set by the U.S. Department of Transportation (DOT = U.S. Department of Transportation). The letters DOT are followed by three four-digit sets of letters and numbers used to identify the manufacturer, the tire series, and most importantly, the date of manufacture. The DOT numeric code is also used by manufacturers that do not ship to the U.S.

How do I find out the age of a tire?

You can find out the age of a tire simply from the code behind the DOT letters. Of these twelve symbols, the last four numbers are important in determining the age of the tire. These indicate the week and year of manufacture of that particular tire. For example, the numbers 0413 indicate a tire manufactured in the fourth week of 2013.

I only have three numbers on my tire!

The four-digit code didn’t come into use until after 2000. Before 2000, only the three-digit code was used as standard. The first two numbers, as with today’s codes, indicate the week the tire was manufactured. The last digits are the year in the decade. You will find the code “078” on a tire manufactured in the 7th week of 1988. In the 1990s, a small triangle was added after these three characters. The “078Δ” designation is on a tire manufactured in the 7th week of 1998, see illustration.

Remember that tires older than four years lose their usefulness and should be replaced.