Rubber ages whether or not you turn a wheel. Ozone, UV, and heat cycles stiffen the compound and weaken the bonds inside the casing — which is why a spare that has ridden in a trailer carrier since 2014 can be a worse bet than a half-worn drive tire from 2022.
Finding the date code
At the end of the DOT code on the sidewall are four digits: week + year of manufacture. A tire stamped 2325 was built in the 23rd week of 2025. The full code is branded on one sidewall only, so if you find a partial marking, walk around and read the other side. On duals the inner code usually faces in — a mirror on a stick beats pulling the wheel.
The ages that matter
- Five years: most tire manufacturers ask for a proper inspection every year from this point on, whatever the tread looks like.
- Ten years: the ceiling most manufacturers publish — take the tire out of service, spares and yard stock included.
- Any age: pull it on sidewall cracking, bulges, exposed cord, or a casing that keeps losing pressure between checks.
Age counts twice on a casing
If you run a retread program, the casing is an asset and its date code follows it for life. Every retreader inspects a casing before it goes into the process and sets its own age cut-off — past that, the casing comes back as scrap however sound the belt package looks. Log the date code when a tire goes on and again when it comes off. A retread also carries the retreader's own DOT identification, so the original casing code stays the number that tells you true age — and most fleets keep retreads off the steer axle entirely.
What "fresh" should mean when you buy
New tires should be recent production. Industry practice treats tires within a few years of manufacture as new for sale purposes, but fresher is better — and you deserve to know what you're getting. Our commitment: we ship fresh production, and if any tire in your delivery is more than two years old by date code, contact us and we'll make it right. That promise is published on our warranty & registration page.
While you're down there
Reading a date code takes thirty seconds, so use the walk-around. Wear bars sit flush with the tread at 2/32" — and federal rules require at least 4/32" of tread on a steer axle, 2/32" on drive and trailer positions. Check cold pressure against the tire placard and the load you are actually hauling. Date code, tread depth, pressure: on every position, that is most of tire safety.