Identify date code on tires with DOT number

date code on tires

Do you want to identify the age of tires? It’s easier than you think. On every car tire, you can find an easily decipherable DOT number that tells you the date of manufacture and the age of the tire. But how do you identify the actual age of your tire? In this article, we will show you the DOT number and how you identify the date code on tires.

date code on tires

What is DOT number?

In the 1970s, the United States Department of Transportation introduced the DOT number. DOT stands for the American “Department of Transportation”. Over the years, this designation has become the standard to identify the age of tires. The so-called DOT number is printed on the tire sidewall. The first two digits indicate the week of production, the last two the year of production.

Date code on tires shows tire age

The DOT is always made up of four components. Thus, behind the letters “DOT” on your tire, you can read the factory abbreviation, the tire size and the production period. Simply put, you can easily tell when and where the tire was manufactured.

Another test to be sure: What is the meaning of the manufacturing date 1217 indicated on the tire? The answer: the 12th calendar week indicates the month of March, and the 17 indicates the production year 2017, so the tire manufacturing date was in March 2017.

But now to the tire age: You can recognize the tire age by the DOT symbol in the last four digits of the row. For example, if the last tire DOT numbers are 4215, the tire was manufactured in the 42nd calendar week in 2015. So that you don’t have to rack your brains while staring at the DOT number, we have put together a simple DOT table for you here:

Date code on tires table

WeekMonthsYear CodeYears
01 – 05January102010
06 – 09February112011
10 – 14March122012
15 – 18April132013
19 – 23May142014
24 – 27June152015
28 – 31July162016
32 – 36August172017
37 – 40September182018

So, if you want to read the manufacturing date of tires, just look at the side of your tire and look for the inscription “DOT”. Then you can match the digits with the help of our table.

As you can see, your tires can indicate their date and place of manufacture quite specifically. But identifying the manufacturing date of tires is only part of the equation. Now the question arises:

DOT number example in the picture

In the following picture, you see “1221”. This stands for the 12th week of 2021.

date code on tires with DOT number

Another example: The tire here is from the 8th week in 2016. Clearly too old to drive but still using it.

Old DOT number

Date code on tires: DOT number before 2000

However, it can also happen that there are only 3 digits at the end of the DOT number. This means that the tire was manufactured before the year 2000. Only the last digit indicates the year of manufacture of the tire. Thus, DOT number 139 can indicate a tire production date in 1999. To identify the correct decade, the DOT symbol is in the form of a triangle for the production period of the nineties.

DOT number before 2000

On tires from the last millennium, you will usually find a three-digit number and a symbol behind it. The first two digits of this make up the week, and the third represents the last digit of the year. The symbols are meant to help distinguish the decades. A triangle stands for the 90s. If the symbol is missing, you have an antique piece from the 80s.

After six years the tire is too old

  • Even if the profiles are not yet worn, you should change tires at the age of six or seven years. TÜV-Nord recommends this.
  • Reason: The rubber compound becomes brittle, the performance decreases with age.
  • Particularly with the purchase of used cars you should pay attention to the age. Otherwise, you will have to pay again after the purchase.
  • The minimum tread depth for a tire is 1.6 millimeters. However, for safety, we recommends a depth of at least 4 millimeters.

What does the age of my tires mean?

As mentioned earlier, few things in life get better with age. Whether the tire is driven on permanently or has only been in storage for a long time – Over time, signs of age become apparent on the stored tire as well:

  • Light and heat: The tire can age prematurely if the storage location is too bright and warm. This is noticeable by cracks.
  • Location: It depends on the type of tire. Without rims, you store your tires ideally standing up, while tires with rims can also be stacked on top of each other or stacked on a rim tree. We recommend you rotate your tires (without rims) once a month; otherwise, it can cause an imbalance.
  • Humidity: Your tire’s rubber does not tolerate water and humidity well and will begin to age faster if stored in a high humidity environment. The consequences of water damage can be very dangerous.

In addition to these factors in storage, you also need to consider the wear and tear caused by tire use. Probably the most important factor for the safety and drivability of tires is the tread depth. In addition, the technical condition of the tire, also keep the date code on tires in mind.

Here it is especially the wear of the treads (worn tread), strength and regularity of the load (commuters more often find cracks and dents in the tire and tire casing) and extreme temperatures (rubber becomes porous) that affect the tire.

However, this is subject to the condition that the tires have been stored under optimal conditions. You can also read helmet size chart.

When should I change motorcycle tire?

Tire age is a crucial safety factor. Experts recommend replacing tires after 10 years, regardless of whether they are summer or winter tires. But tires can also “age” earlier, due to storage. You should check Six-year-old tires regularly for aging cracks damage, also the date code on tires. A specialist workshop is best to do this. The tires of trailers, especially caravans, with 100 km/h approval must not be older than six years.

Tip: The can also check date code on tires to read the age of new tires when you purchase. For frequent drivers such as sales representatives, the age of the tires is less relevant at the time of purchase, as the tread will usually be worn down before the first signs of age appear. For vehicles that are only driven a few thousand kilometers a year, on the other hand, a check can be useful because tire age is a significant safety factor.

In our another article you can everything about when do you need to change tires. >> when to change motorcycle tire & how to do it?

Pay attention to the date code on tires

A properly stored tire only meets the quality requirements of a new tire of the same model up to a maximum of 3 years after the production date.

The date of manufacture of the tires can be easily identify the so-called DOT number or date code on tires. There is a four-digit group of numbers on the tire sidewall beginning with the letter combination “DOT”.

The four digits indicate the calendar week and the year of manufacture, and thus the tire age. For example, the number combination “4308” means that the tire was produced in the 43rd calendar week of 2008.

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