How to Read the DOT Date Code on Your Tires in 2026

The number that matters more than the tread

A tire can look almost new — deep tread, clean sidewalls, no visible cracking — and still be unsafe to drive on. Rubber compounds harden and lose grip as they age, independent of how many miles have been put on them. A tire that sat in a warehouse or on a dealer's rack for five years before it was ever mounted is already five years into its service life before the first mile.

The only way to know a tire's real age is a short alphanumeric stamp molded into the sidewall: the DOT (Department of Transportation) code. Most of that code identifies the manufacturing plant and tire specifications and isn't useful to a shopper. But the last four digits are the ones worth learning to read, because they tell you exactly when the tire was built — down to the week.

This matters most for used tires, since a used tire's tread tells you how much life is left on that tire's clock, but says nothing about how much of the clock has already run from age alone. It also matters for anyone buying a car, a trailer, or a spare that's been sitting unused. Several shops around Alabama handle both new and used tires and can check this for you in a couple of minutes if you're not sure how to read it yourself.

Finding the code on the sidewall

The full DOT code starts with the letters "DOT" followed by a string of up to 12 characters, molded (not printed) into one sidewall of the tire. Depending on when and where the tire was made, it may only appear in full on one side of the tire — manufacturers aren't required to stamp the complete code on both sidewalls, just the inner one at minimum.

Look for the sequence after "DOT" and scan to the end of the string. The last four digits, often set slightly apart from the rest of the code, are the ones to read. If the full code is hard to spot, a shop with a lift and good lighting will usually find it faster than someone crouched next to a parked car with a phone flashlight. This is a standard part of what a tire shop checks during an inspection, tire rotation, or before mounting a tire someone else is selling.

Ozzy’s Tires

Used Tire Shops · Cullman, Alabama

205 Short St SW, Cullman, AL 35055, United States

★★★★★ 4.9 (198)

Decoding the last four digits

The last four digits break into two pairs: the first two digits are the week of the year, and the last two are the year. A code ending in "2219" means the tire was manufactured in the 22nd week of 2019 — late May 2019. A code ending in "0124" means the first week of 2024.

Here's how a few example endings translate:

Before 2000, tire manufacturers used a three-digit code instead of four, which is one of the reasons tires that old should never go back into service even if they look fine — there's no reliable way to confirm the exact year, and a tire from that era is far past any reasonable service life regardless.

How old is too old

There's no single federal cutoff for tire age, but the pattern across vehicle and tire manufacturer guidance is consistent: most recommend close attention to tires once they pass six years from the manufacture date, and replacement by ten years regardless of remaining tread or how the tire looks. Some vehicle manufacturers set their spare tire replacement interval even earlier than that. Heat, UV exposure, and how the tire was stored all affect how fast it actually degrades, which is why two six-year-old tires can be in noticeably different condition depending on where they spent those six years.

This is separate from tread depth, which measures how much rubber is left to channel water and maintain grip. A tire can pass a tread depth check with room to spare and still be a poor choice to put on a car because of its age. The reverse is also true — a tire with low but legal tread and a recent manufacture date is a different risk profile than an old tire with deep tread.

Heat speeds up the clock

Tire aging isn't just a function of time — it's a function of heat, oxygen, and UV exposure acting on the rubber compound. That's why the same guidance that treats six to ten years as a reasonable window for a tire stored in a cool, covered garage in a mild climate doesn't stretch as far in a hot, humid climate like Alabama's. Summers that regularly push pavement temperatures well above the surrounding air temperature, combined with long sun exposure for any vehicle parked outside, work against tires faster than they would in a cooler region.

That doesn't mean every tire in the state needs to be replaced on a fixed schedule. It means the sidewall check is worth doing more often, not less, and that a tire sitting on a used-tire shelf or in a vehicle that spent its life parked outside deserves a closer look at the code before assuming the six-year window still has room left in it.

Why this matters more when buying used

A used tire shop's whole business is reselling tires that still have usable tread left on them. That's a legitimate and often good-value option, but it puts the age question entirely in the buyer's hands unless the shop checks it for you. A tire pulled from a vehicle that was garaged for years, or one that came off a car that was in an accident unrelated to the tires, can have plenty of tread and still be approaching or past the point where age alone is the bigger risk.

ABR Used Tires

Used Tire Shops · Anniston, Alabama

4408 Sprague Ave, Anniston, AL 36206

★★★★★ 4.8 (114)

M&C TIRE SHOP AND AUTO SERVICE

Used Tire Shops · Birmingham, Alabama

2929 Bessemer Rd, Birmingham, AL 35208

★★★★★ 4.7 (73)

Shops that specialize in used tires generally inspect for sidewall cracking, uneven wear, and repair history before reselling, in addition to tread depth. Asking directly about the manufacture date on a specific tire — and checking it yourself before it goes on the car — takes a couple of minutes and removes the guesswork.

Retreaded and commercial tires are a different case

Retreading extends the life of a tire's casing by replacing the worn tread on top of it, and it's common in commercial and fleet tire operations where the casing is inspected and recertified as part of the process. A retreaded tire will carry its own manufacturing and retread dating that a buyer should ask about directly rather than assume from the original casing's age alone, since the two dates aren't the same thing.

L & S Tire & Retread

Used Tire Shops · Andalusia, Alabama

210 E Watson St, Andalusia, AL 36420

★★★★★ 5.0 (6)

For fleet operators, farm equipment, and anyone running trailer tires that sit for long stretches between trips, the DOT code is arguably more useful than the tread gauge. A trailer that only gets used a few weekends a year can rack up age on its tires far faster than it racks up miles, and a blowout on a loaded trailer is a different kind of problem than one on a daily driver.

What a full-service shop checks beyond the date

A shop that does more than just sell tires — mounting, balancing, alignment, and general repair — is set up to catch age and wear issues together rather than in isolation. If a tire is replaced because of age, that's also the moment to check whether the vehicle needs an alignment, since uneven wear from an alignment issue will shorten the life of the next set of tires too.

Branham Tire & Auto

Tire Shops · Cullman, Alabama

101 Arnold St NW, Cullman, AL 35055

★★★★★ 4.8 (412)

Roger's Tire Shop

Tire Shops · Birmingham, Alabama

4030 3rd Ave S, Birmingham, AL 35222, United States

★★★★★ 4.7 (128)

A shop that also handles tire repair can tell you whether a specific tire with a plug or patch is still a good candidate for continued use, or whether the repair plus the tire's age adds up to a replacement being the safer call. That's a judgment call that's easier to make in person than from a sidewall alone.

A quick checklist before you buy or drive on an older tire

A few minutes with a flashlight and the sidewall will answer most of the questions that matter:

• Locate the "DOT" stamp and read the last four digits as week, then year.
• If the tire predates 2000 (a three-digit code instead of four), don't put it into service — treat it as scrap regardless of appearance.
• Compare the build date against today's date rather than against when the vehicle was purchased, since a tire can sit unsold or unused for a long stretch before it's ever mounted.
• Check all four tires and the spare separately. It's common for a vehicle to have tires from different manufacturing dates, especially if one was replaced after a flat.
• If the tread looks fine but the tire is past six years old, ask a shop to look at the sidewall rubber itself for small surface cracks, which often show up before any other visible sign of age.

None of this requires guessing. The code is right there on the tire, and any shop that handles mounting or repair deals with this exact check routinely.

Where to get a tire checked in Alabama

Several of the shops above are listed with their service details, hours, and location on this directory. Shoppers in north Alabama can browse used tire dealers in Cullman or the full list of Cullman tire and auto shops. In east Alabama, Anniston's used tire shops are listed alongside Anniston's broader auto repair and tire directory. Birmingham shoppers can check used tire shops in Birmingham or all Birmingham tire shops, and in south Alabama, Andalusia's listings include tire and retread specialists.

None of this requires special tools. A flashlight, a few minutes, and knowing which four digits to look for is enough to check any tire — on a car you're buying, a used tire you're considering, or the spare that's been sitting in the trunk since the car was new.

The takeaway

Tread depth and tire age are two separate checks, and a tire that passes one can still fail the other. Find the DOT code on the sidewall, read the last four digits as week-and-year, and treat anything approaching six years as worth a second look and anything past ten as due for replacement regardless of how the tread looks. For used tires, trailer tires, and spares especially, that thirty-second check is worth doing before the tire goes anywhere near the road — and any of the shops listed above can walk through it with you if you'd rather have a second set of eyes on it.