How Old Is Too Old? Reading the DOT Date Code on Your Tires

Tread depth is the measure everyone knows. Age is the one almost nobody checks — and a tire with plenty of tread can still be unfit for the road.

Rubber is a chemistry problem as much as a wear problem. Oxidation, UV exposure and thermal cycling gradually stiffen the compound and weaken the bond between the rubber and the internal steel belts. This happens whether the tire is doing 30,000 km a year or sitting on a shelf.

Finding the DOT Code

Every tire sold in North America carries a DOT code moulded into the sidewall. It starts with the letters DOT and ends in a group of digits. The part you want is the last four digits:

• The first two are the week of manufacture (01–52)
• The last two are the year

So 2624 means week 26 of 2024 — roughly late June 2024. 0521 means week 5 of 2021, early February 2021.

Two practical notes. The full code is often moulded on only one side of the tire, so if you cannot find it, look at the inboard face. And tires made before 2000 used a three-digit code — if you find one of those, the tire is over 25 years old and needs to come off immediately.

When Age Alone Means Replacement

There is no single legislated expiry date, but there is broad industry consensus:

• Under 6 years — age is generally not the limiting factor. Judge on tread depth and condition.
• 6 to 10 years — inspect annually and carefully. Look for fine cracking in the tread grooves and sidewall.
• Over 10 years — replace, regardless of tread depth or appearance. Many manufacturers and vehicle makers state this explicitly.

This applies to the spare too, which is the one everybody forgets. A spare that has lived under the boot floor since the car was built may be a decade old and has never been inspected. See spare tire types.

What Ageing Looks Like

• Fine cracking in the base of tread grooves or on the sidewall — often called weather checking or crazing.
• A hard, glazed feel to the rubber compared with a new tire.
• Discolouration, particularly a brownish or grey cast on the sidewall.
• Reduced wet grip that appears even though tread depth looks acceptable.

The failure mode that matters is tread separation — the tread belt parting from the carcass, typically at highway speed and typically without warning. It is exactly as bad as it sounds.

Why This Matters When You Are Buying

Here is the practical point. A tire that has sat in a warehouse for four years is sold as new and legally is new — but it has already used a significant portion of its usable life before you drive a metre on it.

So when you buy, ask the date code. A reputable shop will not blink at the question. As a reasonable standard:

• Ideally within 1 year of manufacture
• Acceptable up to about 2 years
• Beyond that, expect a meaningful discount and understand what you are accepting

This is also the single strongest argument against used tires. A used tire may be sold on tread depth with no mention of age at all — see used vs new tires.

Slowing the Clock

You cannot stop ageing, but storage conditions make a real difference — which matters a lot in Ontario, where most drivers store a seasonal set for half the year:

• Cool, dark and dry. UV and heat are the main accelerants.
• Away from electric motors. Ozone from motors degrades rubber; furnace rooms are a poor choice.
• Clean before storage. Road salt and brake dust are corrosive.
• Bagged, upright or stacked correctly depending on whether they are on rims.

Full detail in our Ontario off-season tire storage guide. Correct storage genuinely extends usable life; a set stored badly on a hot garage floor in direct sun will age noticeably faster.

Frequently Asked Questions

How do I find out how old my tires are?

Look for the DOT code moulded into the sidewall. The last four digits give the manufacture date: the first two are the week and the last two are the year. For example 2624 means week 26 of 2024.

How long do tires last before they expire?

There is no legislated expiry, but industry consensus is to inspect carefully from six years and replace at ten years regardless of remaining tread depth. Rubber degrades with time as well as use.

Are five year old tires with good tread safe?

Generally yes, provided they show no cracking, have been stored and maintained properly and the tread is adequate. Inspect them annually from year six onward.

Should I buy tires that are two years old?

Tires up to about two years from manufacture are commonly sold as current stock and are acceptable. Beyond that you should expect a discount, since you are buying into an already-reduced service life.

Does the spare tire age too?

Yes, and it is the most commonly overlooked tire on the vehicle. A spare that has never been used still ages. Check its date code and condition at least once a year.

Can old tires be dangerous even with tread left?

Yes. The main risk is tread separation, where the tread belt parts from the tire carcass. It typically happens at speed and with little warning, which is why age limits exist independently of tread depth.

Fresh Stock, Brand-New Tires

We sell brand-new tires and we are happy to show you the date code before you buy. Ask us — it is a fair question and you should be asking it everywhere.

Atika Auto Parts stocks brand-new all-season, all-weather, winter and light-truck tires at 80 Hale Rd, Unit 3, Brampton — with expert fitting and delivery across the GTA. Browse our current tire stock, call +1 (204) 962-8513, or send us your vehicle details and we will quote you the same day.