DOT date codes and tire age
In DOT date codes the last four digits are the week and year a tire was built.
Tire age
Every tire built for on-road use in the United States carries a tire identification number molded into the sidewall, beginning with the letters DOT. The last four digits of that number are the date of manufacture.
The first two are the week of the year, the last two the year. A tire ending 2419 was built in the twenty-fourth week of 2019. The full number also identifies the plant that made it and the tire's size and type codes.
A recall uses these to target specific production runs instead of an entire model. What no federal rule provides is an expiry date. No legal age exists at which a tire must be replaced.
The recommendations that circulate come from individual manufacturers, not from any regulation, which is exactly why the date matters and why you have to find the recommendation that applies to your tire and not assume a universal one.
Reading the identification number
The number is molded, not printed, and on many tires the full number appears on only one side. If you cannot find the four-digit date, check the other sidewall before concluding the tire does not have one. It is normally in a recessed panel at or near the bead area instead of out on the shoulder with the size markings.
What aging does to a tire
Rubber compounds change over time whether or not the tire is used. Oils and anti-degradants migrate out of the compound and are consumed by exposure to oxygen, ozone and ultraviolet light. The rubber becomes harder and less able to deform into the road surface.
The visible symptom is fine cracking in the sidewall and between the tread blocks. But the change in grip precedes the cracking.
NHTSA’s tire-aging guidance identifies sunlight, heat, storage and maintenance as factors, and warns that appearance alone cannot reveal tire aging. Follow the tire and vehicle makers’ age recommendations even where tread remains.
There is no federal expiry date for a tire; no age threshold applies to every tire, because the recommendations that exist come from individual manufacturers and differ. Find the date code, then find what the maker of that tire, or your machine's manufacturer, says about age, and treat visible cracking as decisive regardless of the number.
Why a brand-new tire can be several years old
A tire sitting on a shelf is aging, and popular sizes turn over quickly while unusual sizes do not. It is entirely possible to buy an unused tire that was built four years ago, and for a size fitted to an uncommon machine it is close to routine. An older manufacturing date alone does not establish fraud or a tire defect.
But it is information you are entitled to have before paying.
The practical habit is to read the date code before fitting, not after, including on a tire fitted by a shop. Checking a tire's date is a thirty-second job at the point of sale and a considerably more expensive one once it is mounted and balanced.
| Question | What the code can answer |
|---|---|
| When was this tire made? | Exactly: to the week, from the last four digits. |
| Is this tire subject to a recall? | Yes, in combination with the rest of the identification number, which identifies the plant and production details a recall names. |
| Has it been stored well? | No. Storage conditions matter as much as age and leave no mark in the number. Inspect the sidewall for fine cracking. |
| Is it legally expired? | No such thing exists in federal rules. Any age threshold you are given is a manufacturer or workshop recommendation. |
| How much life is left in it? | No: that is a tread depth and condition question, and it is separate from age. |
Checking for a recall
Tire recalls are targeted using the identification number, because it identifies the plant and the production run. That is why keeping a note of the full number of the tires on your machine is worth the two minutes it takes, particularly on a machine that is stored for long periods and may not be ridden between a recall being announced and the tire being needed.
For on-road machines, the federal recall database covers both vehicles and tires and the tire search works from the identification number and not from a VIN. Off-highway machines and their tires fall to the consumer-product side instead. A different agency and a different search.
References
- Federal rule Tire identification and recordkeeping: the DOT tire identification number: U.S. Government Publishing Office (eCFR), 49 CFR Part 574.
- Federal rule FMVSS No. 119: New pneumatic tires for motor vehicles with a GVWR of more than 4,536 kg and motorcycles: U.S. Government Publishing Office (eCFR), 49 CFR § 571.119.
- Federal rule Product Information Catalog and Vehicle Listing (vPIC): VIN decoding and recall lookup: National Highway Traffic Safety Administration.
DOT date codes and tire age questions
How do I read a tire date code?
Find the DOT tire identification number moulded into the sidewall and read the last four digits. The first two are the week of the year and the last two are the year, so 2419 means the twenty-fourth week of 2019. On many tires the complete number is moulded into one sidewall only, so check both sides before deciding it is missing.
Is there a legal expiry date for tires?
No federal rule sets one. No age makes a tire illegal to use. The age recommendations that circulate come from individual tire and vehicle manufacturers instead of from regulation; that is precisely why the date code matters: it lets you apply whatever recommendation applies to your tire.
Why does an unused tire go off?
Because the compound changes with time regardless of use. Oils and anti-degradants migrate out of the rubber and are consumed by exposure to oxygen, ozone and ultraviolet light, leaving the rubber harder and less able to key into the road surface. Fine cracking is the visible late symptom; the loss of grip starts earlier.
Can a brand new tire be several years old?
Yes, and for uncommon sizes it is close to routine. A tire on a shelf ages the same way one on a machine does. Not fraud. It is information worth having before you pay, which is why reading the date code at the point of sale is a better habit than reading it after the tire is mounted and balanced.
Does the date code tell me if the tire was stored well?
No. Storage conditions matter at least as much as age and leave no trace in the number. A tire kept cool, dark and away from ozone sources ages far more slowly than one that sat in sunlight; that is why a visual inspection for fine sidewall cracking is a necessary companion to reading the date.
What do the characters before the date mean?
They identify the manufacturing plant, a code for the tire’s size and type, and a manufacturer’s own optional code. Together with the date they identify a specific production run, which is how a tire recall can be aimed precisely, not at an entire model; that is also why the whole number, not just the date, is worth recording.
Do ATV and UTV tires have date codes?
Only if they carry a DOT marking. Most off-highway tires do not, because the federal tire standard that requires the identification number applies to on-road use. Some UTV tires intended for road-legal machines do carry it. Where there is no code, age has to be judged from purchase records and from the condition of the rubber.
How do I check whether my tires are recalled?
Tire recalls are identified by the tire identification number and not by a vehicle VIN, so you search the number moulded on the sidewall. For on-road machines and tires, the federal recall database covers both. Off-highway machines and their components fall to the consumer-product agency. A separate search.
Should I replace a tire with plenty of tread but old rubber?
Judge it on condition and on the recommendation that applies to that tire, not on tread depth alone. Fine cracking in the sidewall or between the tread blocks is decisive whatever the depth. Rubber that has hardened noticeably compared with a new tire of the same model has lost grip that tread depth does not restore.
Where exactly is the date code on the sidewall?
Usually in a recessed panel near the bead area instead of out with the size markings, and often on the inboard sidewall only, which on a fitted wheel may mean looking from behind or removing the wheel. It is moulded, not printed. So it does not wear off, but it can be hard to read on a dirty tire.
Does storing a machine on its tires damage them?
Standing in one position for a long time lets the tire take a flat spot. Usually it works out with use. On an older, harder tire it sometimes does not. Storing on stands with the weight off, or at least moving the machine periodically, avoids it. The bigger storage variable is sunlight and ozone exposure and not the load.
Do tire covers help?
For a machine stored outdoors or in a bright space, yes: the ageing mechanisms include ultraviolet exposure and ozone. A cover reduces both. It does nothing about heat if the machine is in a hot space. A cover that traps moisture against the machine creates a different problem, so ventilation matters alongside it.
Motorcycle tire sizes: the rest of the sidewall; Size, load index and speed symbol, and what each one is rating.
ATV and UTV tire sizes, which usually carry no code; Off-highway tires are outside the federal standard that requires the number.
- Fitment: the four questions in order
- Age belongs to the third one: whether the tire can still carry the load.
Street motorcycle ownership: which agency handles a recall; On-road tires and machines go one way; off-highway goes another.