Is It Safe to Buy Used Tires? Read the Date Code First

Yes, a used tire can be safe, but only if it passes three checks that have nothing to do with how shiny it looks: its age, its tread depth and its sidewalls. The age is printed on the tire in a four-digit code that federal rules require, and most buyers never look at it. A tire with deep tread can still be too old, and a newer tire can still be ruined by one pothole.

Deep tread tells you how much a tire has been driven. The date code tells you how long it has been alive. Check both.

If you shop for tires in DC, Maryland or Virginia, where winter brings cold snaps, salt and potholes, these checks matter more, not less. Here is how to do each one in a few minutes, and why the advice you find online about tire age disagrees so much.

How do you read a tire's date code?

Every tire sold in the US carries a Tire Identification Number, a string that starts with the letters "DOT". Under the federal rule, 49 CFR 574.5, the last group of that number is a four-digit date code:

• The first two digits are the week the tire was made. "01" is the first full calendar week of the year.
• The last two digits are the year.

So a code ending in 3922 means the 39th week of 2022, and 0109 means the first full week of 2009, the exact example the regulation gives.

Here is the detail that trips people up: the rule only requires the full number on one sidewall of a new tire. If you look at a tire and see "DOT" followed by a short code with no date, you are probably looking at the wrong side. Turn the tire around, or look at the inside face if it is mounted on a car, before you decide the date is missing.

How old is too old for used tires?

This is the question where online answers clash, with some saying five years, some six and some ten. The reason is that there is no tested, legal expiry date for a passenger tire. The numbers you see come from company guidance, and the companies were open about that:

Bridgestone/Firestone even said, as reported at the time, that it had no technical data to support a specific service life; it followed a Japanese tire makers' association recommendation.

What this means when you buy used: treat ten years as a hard stop, because that is the line the tire makers themselves drew. Treat six years as the point where you start doubting, because that is where several carmakers drew theirs, and your own owner's manual may say the same. A tire that is two or three years old, a common search ("is it ok to buy 2 year old tires"), is well inside every limit above. Its condition and history matter far more than its age.

One more thing the date cannot tell you is how the tire was stored. A tire kept indoors and one baked on a car outside for years can share a date code and age very differently, which is why the sidewall check below still matters on a "young" tire.

What tread depth is too low?

Virginia's state safety inspection gives a clear, official line. Under the Virginia Administrative Code (19VAC30-70-500), a tire on most passenger vehicles fails when the tread is under 2/32 of an inch in two side-by-side grooves at its thinnest point, confirmed at two more points around the tire. It also fails when the tread wear indicators, the small raised bars molded across the grooves, touch the road in two neighboring grooves at three spots around the tire.

For a used-tire buyer, that 2/32 line is the floor, not the goal. A used tire that is close to 2/32 may pass today and be worn out in a season. Look for those wear bars yourself. If the tread is almost level with them, you are buying a tire that is nearly finished, whatever the price.

What damage should make you walk away?

The same Virginia rule lists the defects that fail a tire outright. They make a good checklist for any used tire, in any state:

1. Cord or fabric showing through the worn tread.
2. Bulges, knots or bumps on the sidewall, or signs of a broken belt, which can feel like a wave or lump under your hand.
3. Tread separating from the body of the tire.
4. A cut deep enough to show the ply or belt underneath.
5. A repair in the sidewall. Virginia accepts plugs and patches in the tread area only, not the sidewall.
6. Regrooved or recut tread on an ordinary car tire. Only commercial tires marked "Regroovable" on both sidewalls may be recut.
7. A tire marked for another use, such as farm, off-highway or trailer-only use, on a passenger car.

Run your hand slowly around both sidewalls, inside and out, rather than trusting your eyes alone. If a tire is sold loose, not on a wheel, ask whether you can see it inflated, because a flat tire hides bulges.

Does the used tire match your car?

A perfect tire can still be the wrong tire. The U.S. Tire Manufacturers Association says replacement tires should have the same size, load index and speed rating the car or tire maker recommends, and never a smaller size or lower load capacity. You will usually find your car's numbers on a label inside the driver's door, in the glove box or in the fuel door.

The association also recommends replacing all four tires at once. If you only replace two, it says to put the newer pair on the rear axle. If you must replace a single tire, it suggests pairing it with your deepest-tread tire and mounting both on the rear. That is worth knowing before you buy one bargain tire to replace one damaged one.

How do you check if a used tire is recalled?

Recalled tires can stay in use long after the notice, and a used tire comes with no letter from the maker. The U.S. Tire Manufacturers Association runs a free lookup tool, launched in June 2016: you type in the tire's DOT identification number, and it checks recalls by its member companies since 2000. The association said at launch that its members made up about 80% of US tire shipments, so a clean result is reassuring but not a guarantee for every brand.

For a wider habit on recalls, our guide on how to check if a product is recalled before you buy used walks through the same idea for everything else in your cart.

The bottom line

A used tire is a fair buy when it is comfortably under ten years old (and ideally under six), well above the 2/32 floor, clean on both sidewalls, recall-free, and the exact size and rating your car calls for. Miss any one of those and the low price is not a deal. Read the date code on both sides, run your hand around the sidewalls, and check the number against the recall tool before you pay.

Tires are not the only thing with a hidden date. Our list of five dates to check on anything secondhand covers the rest. If you are browsing other secondhand and open-box finds, you can look through what is in the shop right now, and the FAQ explains how buying from us works.

Know someone shopping for winter tires on a budget? Send them this before they buy.