If you look closely at any tire, you can find an engraved DOT number. This number gives you valuable insights into the tires keeping you safe. However, it is not always clear to drivers what their DOT number is communicating. The local auto mechanics are here with the full breakdown of how to read a tire’s DOT number.
Every tire identification number begins with the letters DOT (Department of Transportation). It is a marker that verifies you are getting tires that meet the Department of Transportation’s guidelines. It also serves as a clear, universal starting point for a tire’s TIN (tire identification number).
The next group of numbers contains two characters that indicate your tire’s plant code. Every tire manufacturing plant has a unique two-character code, often made with one number and one letter. Why is this important? If there is a tire recall, safety issue, or another tire concern, it can be traced back to the plant that produced the tire(s) in question.
The next two numbers or letters are your tire size code. The tire size code is a little less straightforward than other markings. Originally, the National Highway Traffic Safety Administration (NHTSA) had a universal list of tire sizes and the two-digit codes that represented them. However, the DOT now lets manufacturers determine their own code for tire size, according to the US Federal Register. This change was intended to make it easy for manufacturers to produce new tires without requiring the NHTSA to update its code list. Unfortunately, it makes it challenging to translate the tire size on your tire’s DOT number. Thankfully, there is an easier way to tell your tire size (more on this below).
The third set of values indicates the manufacturer’s characteristics. It is essentially a space for manufacturers to provide tire distinction or other brand-specific insights. The US Federal Register states, “The third grouping may be used at the manufacturer’s option to provide any other significant characteristics of the tire.
Except for cases in which a tire is manufactured for a brand name owner, the third grouping is not required.” Manufacturers then submit their list of codes to the National Highway Traffic Safety Administration.
Much like the tire size code, this grouping often does not provide valuable information for drivers. It is more so used for recalls, errors, and other official identification needs.
Without ever touching the road, a tire can go bad simply due to its age. After 5 years of age, tires begin experiencing thermo-oxidative degradation. This chemical reaction can severely impact tire safety on the road.
The final four digits on your DOT number will tell you the tire’s age. The first two numbers of this grouping indicate the week of the year your tire was manufactured. The final two digits indicate the year that your tire was manufactured. For example, if your final four DOT numbers are 3020, your tire was manufactured in the 30th week of 2020. You can find more information in our full guide to tire age here.
While DOT numbers are helpful, they might not tell you everything you need to know about your tires. As tire experts, we often have customers ask:
Many drivers expect to find the answers to these and other questions in their DOT number, but this is not the case. Tires brands often include additional insights on the face of the tire. However, it is frequently much easier to view tire information on your tire panel. If you open your driver’s-side door and turn to face the seat, you will find a sticker against your door frame with information about your tires. You can also find additional details in your owner’s manual.
When you are due for new tires, the mechanics at Chapel Hill Tire are here for you.
We proudly serve the greater Triangle area with our 10 locations across Raleigh, Apex, Cary, Durham, Chapel Hill, and Carrboro. Our mechanics also commonly serve nearby areas, including Knightdale, Pittsboro, Wake Forest, Hillsborough, Morrisville, and beyond. You can conveniently buy your new tires online using our Tire Finder tool. For all of your tire services, vehicle services, and car care needs, make an appointment today with your nearest Chapel Hill Tire.
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Are you having difficulties reading the DOT number of your tires? Do you want to know how to read tire date codes? If you have lost the receipt of your purchase, you might be having difficulties knowing the exact age of your tires. This issue is common and you can find the solution from your tires.
Just observe your tires, you will get the answer.
*Picture Copyright: UTires.com
How to Read Tire Date Codes?Whether you are financing your tires or purchasing them, it is important to understand how to read tire date codes. The numbers are present on tires only. You just need to know how to get them. You might have difficulties while reading codes on old tires. Keep reading to know how old your tire is.
Ways to Get Your Tires DOT NumberLook at all the sides of the tires. There are a bunch of numbers and letters. It might seem like a jumble. But this is helpful information about the tire. Find the number that starts with DOT and followed by ten to twelve series. This code will reveal a lot of things about your tires. You will know the tire size, year, and place of the manufacturing with the unique code of the manufacturer. You can also rent a wheel payments to know more about tires. Once you rent a tire payments, you will not have to be bothered about the manufacturing year.
They will take care of this. You just need to look for a rent a wheel return policy to make it more beneficial for you.
Remember that the last four digits of the code are the date the tire was manufactured. You can check the first two digits of the DOT code to know the week of the manufacturing. The last two digits will reveal the manufacturing year. For instance, when it was written in 0203, the manufacturing year was 2003. But it is a bit tricky to know the manufacturing year of tires manufactured before 2000.
Tires Manufactured Before 2000You need to check the last three digits of the DOT code. Check the first two digits to know the week. For instance, when the last three digits read 022, you should understand that the tire was manufactured in the 2nd week of that year. You might be thinking about how to know the year. The year is the 2nd year of that decade. It is easy to get confused to know the decade.
It might be harder to know the exact decade. There might be some other indications to know the year.
*Image Copyright from kilgoretirecenter.com
What About the Incomplete DOT NumbersIncomplete DOT numbers mean the current DOT regulations demand the complete number to be written on one sidewall only. When you find a few digits on the opposite sidewall, you can check the other sidewall to find the complete DOT number.
Reading DOT Tire NumbersNow you know how to read tire date codes. You can simply check at the sidewalls of tires to avoid any further confusion. Also, never lose your purchase receipt. If you do so, you might not get the warranty benefits. So, keep the receipts in a safe place and avoid any confusion by checking the DOT code. Whether you are interested in learning about wheel alignment or more about DOT numbers, our professionals here at Dan the Tire Man can answer your inquiries.
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Determining the date of manufacture of a car tire is an important point in determining how long a product can be used without risk to road users.
You can find out the year of manufacture of rubber by special markings on the side of the product. This indicator should influence the final choice of the consumer when buying tires, while also taking into account the country of manufacture.
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80% of sales outlets, when asked if tire age matters, answer no. However, this is 100% fraud. According to research by manufacturers Hankook, Continental and other global brands, a tire can be stored in proper conditions for up to 5 years from the date of production. Therefore, when asked whether this index is important, the correct answer is yes.
There are differences in terms of service life and storage of different models. For example, tires "Bridgestone-Blizak" or "Ice-Cruiser-7000" with proper storage retain their properties for up to 5 years, and summer models can be stored for no more than 120 months.
Buying a fresh product, the motorist guarantees himself the necessary margin of time, in which the rubber will retain optimal elasticity, strength and tenacity. If the age of the tire is 3-4 years or more, the probability of cracking increases critically, and traction is lost. Winter options can completely lose their properties and become coarse, which is fraught with an increase in the braking distance at times.
Different countries have their own markings that determine the date of manufacture of car tires. However, in the early 2000s, manufacturers began to adhere to common standards. This has become a necessity due to the distribution and mixing of products. For example, for foreign brands Kumho, Yokohama, Dunlop, Pirelli, a special marking is established, where the exact data is encrypted.
Recently, other manufacturers have joined the general standards:
The following is a more accurate determination of the production time of tires from popular manufacturers.
Department of Transportation regulations require all tire manufacturers to affix production date markings on their products. The code should be separated from other designations, which makes it stand out for better identification.
The requirements of the organization say that for this index it is necessary to choose a place on the side of the rubber, in a place visible to the buyer, therefore, the index must be viewed on the sides.
However, the exact location is not specified, brands have the right to place indexes at their discretion.
For models made by manufacturers such as Goodyear, Michelin, Nokian, the location of the encoding in a separate oval is relevant. The index consists of 4 digits, which makes it easy to find and decipher.
For example, we can take Nokian Hakapelita tires of 7/5/8 generations.
In this case, it is clear that the index is highlighted with a rubber oval, the numbers stand out among the general designations.
Also on the market you can find products with strange indexes like YYY 2015/2117 and others. You can find it on the side of the tire.
These are typical identifiers for the Yakohama brand.
From Goodyear you can find the following designation:
As you can see from the photo, the code numbers are not surrounded by rubber circles or squares, but simply written during vulcanization.
As of 2022, there is a generally accepted marking of the date of manufacture of automobile tires according to the DOT code. At the same time, for cars, trucks and buses, the rules are the same.
Side parts on tires of brands Bridgestone, Michelin, Toyo, Kama contain the so-called DOT coding.
The index itself consists of several characters, but in this case, the buyer should be interested in the last 4 digits.
The photo shows the standard marking, where the first two digits "31" indicate the calendar week, and "03" the year. Thus, it can be deciphered that the above tire was released in August 2003.
The distribution for weeks is taken into account according to the ISO 8601 regulation, where weekly calendar deductions are strictly broken down.
Also, on some modifications of rubber, you can find the type designation "YYY2018" and similar. This is especially often indicated on Yokohama brand products. Having met this marking, you should not be afraid. The first three letters are not taken into account, the numbers are interesting - 2018 tells the buyer that the product was released from the assembly line on the 20th week of 2018.
“In the bins” of some unique stores, you can still find wheels with three-digit indexes like 125 or 129.
This is a standard marking for parts manufactured before 2000. At the same time, there is no distribution of winter or summer tires.
This also defines the week and year of manufacture. To accurately understand the situation, you need to pay attention to the place after the extreme figure. For example, if there is a space or a triangular character after the code, this determines 90s, and in the absence of extraneous marks, the model was released in the 80s.
For example, we can take a standard European brand tire. Here you can determine the production time in this way.
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Specific dates depend on the quality of the material, storage conditions. For example, the ideal storage environment is a dry shop where there are no temperature fluctuations, minimal dampness and no direct sunlight. If all parameters are met, the product can be stored for 7-8 and 4-5 years for summer and winter tires, respectively.
More precise studies were carried out by MICHELIN, Continental and others. Artificial tests confirmed these results and showed that a tire that has been in storage for 2-3 years practically does not differ from a fresh one in terms of characteristics. In 2022, you can take products released after 2014-15. And for products of 2012, the critical moment of decommissioning has already come.
At the same time, the data is relevant only for branded products such as Blizzak Spike 01, Goodyear, Hankook and analogues of Japanese or European production.
For simple modifications, it is necessary to revise the terms down. This makes it difficult to determine that cheap tires may not be equipped with dates. Therefore, such factors need to be carefully considered.
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Car drivers who purchase a new set of tires do not think that the purchase may not be "the first freshness", that is, not this year. Meanwhile. This affects their performance. And not in the best way. After all, tires produced several years before the start of their service life may lose some of their properties.
This is due to improper storage and the natural process for rubber - aging.
To avoid such a "surprise", each motorist must be "fully armed" at the time of purchase, that is, know how to look at the tire release date and what are the consequences of using stale goods. We will also talk about how to recognize the suitability of tires for use, which is especially important for those who buy used rubber.
Each tire has a marking on the side with numbers inside. There may be three or four of them. The first option says that the tire was released before the year 2000, and the second says that later. Such marking is mandatory, as is its prescribed form. This applies to all tires from all manufacturers targeting markets where DOT certification is mandatory.
The decoding of the four-digit marking is as follows:
Therefore, if you see 1208 in the oval stamp, this means that the tire was released in March 2008.
Legacy labeling is more confusing. The fact is that in the three-digit marking the year is indicated by one digit, and therefore, for example, the nine at the end of the code can indicate two options for the production of tires (1999 and 1989).
There is a subtle nuance that allows you to still deal with this confusion in dates. This is the presence of a space (or triangle) after the numbers. The presence of a gap indicates 1999, and the absence indicates 1989. This feature suggests that earlier manufacturers did not count on the fact that their products could “hang” for such a time somewhere in warehouses or at retail outlets.
The new encoding option is more convenient and understandable. Sometimes there may be English letters in front of the numbers, but since they do not refer to the date of manufacture of the tires, the average driver may not pay attention to them. So we found out that if you know, then there is nothing difficult in determining the production date.
Based on the fact that the service life of tires is at least five years, Manufacturers guarantee that during this time the declared characteristics of tires do not change. However, in fact, not everything is so rosy. Features of operation or storage are a very significant factor that changes the condition of tires. But favorable operating conditions extend this period.
That is, careful use contributes to the fact that tires last much longer than the designated period. So it's not a judgment. Both the appearance and quality indicators of tires will be within the normal range, so it will be safe to use it. I must say that the features of aging depend on the material, that is, on the rubber itself. And they can vary greatly. And this means that the place of production of tires, in other words, the manufacturer, matters.
The second significant factor influencing aging is the conditions in which the rubber has got (operational features and storage conditions of tires).
Time destroys rubber, it loses elasticity, becomes more brittle. Plus the adverse effects of temperature, ultraviolet radiation, moisture. It is recommended to store tires in a packaged form (in polyethylene, polypropylene), the room should not be hot, but it should not be cold either. Humidity should also be kept to a minimum, and certainly no exposure to sunlight.
Tires with discs are stored inflated, preferably suspended (for example, on the wall), in a dry and warm room. Tires without rims are stored in stacks. It can also be vertical. They need to be turned over from time to time. Today, auto centers offer storage of tires, and right there, all the necessary conditions for storage are met, ensuring the preservation of the quality of rubber for many years.
How tires should be stored
Old tires are identified by the condition of their sidewalls. The aging process is characterized by the appearance of microcracks on the rubber surface.
The color of the tires also changes. Instead of a rich black color, it becomes, as it were, faded. In addition to these obvious, conspicuous signs, there are others that are less obvious. But, as a rule, these two are enough to determine. Such tires are not suitable for operation, and must be replaced. The verdict is clear, even if there is no significant tread wear.
Many car enthusiasts are interested in the question of the advisability of buying new tires that were released not this year, but several years ago. An unambiguous answer cannot be given here. Since the final result of the state of the tire at a certain point in time depends on many factors. The conditions of storage / transportation, as well as the initial quality, depending on the manufacturer, matter.
Auto giants approach this issue thoroughly, spending significant funds on research related to the quality of their own products. In addition, various chemical compounds are added to the raw material composition, which improve the quality of rubber in many respects, including those that slow down aging.
