Tire date code decoder

NHTSA says to look on the tire sidewall for the DOT Tire Identification Number, or TIN. Under 49 CFR 574.5, a new tire carries a TIN consisting of 13 symbols molded into the sidewall. The final four digits identify the week and year of manufacture.

General Tire describes the characters following DOT as identifying the manufacturing location, tire size, manufacturer’s code and manufacture date. NHTSA says to look on both sides of the tire because the TIN may not appear on both sides.

Under 49 CFR 574.5, the first two date-code digits identify the week, beginning with 01 for the first full calendar week. The last two digits identify the year. A calendar week runs from Sunday through Saturday.

The regulation’s example, 0109, means the first full calendar week of 2009: January 4, 2009 through January 10, 2009. By the formula, a tire with this code is 17 years and 9 months old on October 15, 2026. The code identifies a manufacturing week, not an exact day.

Code 2524 means week 25 of 2024, from June 23, 2024 through June 29, 2024. By the formula, its age is 2 years and 3 months on October 15, 2026. Code 4419 means week 44 of 2019, from November 3, 2019 through November 9, 2019. By the formula, its age is 6 years and 11 months on the same check date.

NHTSA says aging changes a tire’s rubber and other components through service, storage and environmental conditions. It warns that tires become more prone to failure as they age. NHTSA reports that some vehicle and tire manufacturers recommend replacement at six to 10 years, regardless of treadwear.

Michelin recommends a thorough inspection by a trained tire professional at least annually after five years of service. As a precaution, Michelin recommends replacement ten years after manufacture, regardless of remaining tread depth or apparent condition. That recommendation includes spare tires.

These recommendations do not establish a universal expiration date for every tire. Michelin says age alone does not determine serviceability; wear, condition and performance also matter. NHTSA recommends monthly inspections for inflation pressure, treadwear and damage; for inflation pressure, see the tire and loading placard on the driver's door jamb.