Every tire sold in the United States carries a DOT code on its sidewall that encodes the week and year it was manufactured. Knowing how to read this date helps you determine whether a tire is too old to safely use — even if the tread looks fine.
The DOT (Department of Transportation) code is a series of characters molded into one sidewall of every tire. It begins with "DOT" and is followed by a series of letters and numbers. The last four digits of this code indicate when the tire was manufactured: the first two digits represent the week of the year, and the last two represent the year.
The complete DOT code is molded onto only one sidewall of the tire, so you may need to look at both sides to find it. It's typically located near the bead area (the inner edge of the sidewall closest to the wheel rim). The code is stamped in a recessed oval and reads something like: DOT U2LL LMLR 2419.
Take the last four digits of the DOT code. The first two are the week number (01–52) and the last two are the year. Example: "2419" means the 24th week of 2019 — approximately June 2019. Tires made before the year 2000 used only three digits for the date code, making the decade ambiguous on very old tires.
Rubber degrades over time through oxidation and UV exposure, regardless of whether the tire has been driven on. The degradation causes the rubber to harden, develop micro-cracks in the sidewall and tread, and lose elasticity. This weakens the tire's structural integrity and increases the risk of blowout, even if the tread looks adequate. Replace tires more than 6 years from their manufacture date; retire all tires beyond 10 years.
