In most cases, new tires come with a 10/32 to 12/32 tread depth, and with driving, that parameter decreases until it drops below 6/32 or 5/32, which means it’s time to consider replacing your tires. While there’s no hard-and-fast rule, and no federally mandated safety guidance on when a tire should be (ahem) retired, many carmakers and experts advise replacement between five and six years from the manufacturing date.While the dot and the federal motor carrier safety administration (fmcsa) do not outline specific requirements for tire replacement based on tire age, the national highway traffic safety administration (nhtsa)—which falls under the dot—advises replacing tires every 6–10 years, even if they appear to be in good .As a precaution, Michelin recommends replacing tires ten years after their date of manufacture, regardless of remaining tread depth or apparent condition. This recommendation includes spare tires.Discount Tire recommends that you replace your tires after 6 years of age, regardless of tread depth. For your safety, we will not service a tire that exceeds 10 years of age. You can find your tire’s age in its DOT Identification Number, which you’ll find stamped on the tire’s sidewall.