Tires have important information printed on their sidewalls such as diameter, size, aspect ratio, and DOT number. These tire markings help drivers make informed decisions when choosing the right product. This article focuses on the DOT code, which provides crucial details about tire safety compliance, age, and manufacturer. Also, here you will better understand why it is essential to consider the DOT number when buying tires and its regulations in the U.S.
What Is the Tire DOT Code?
The DOT code is the unique "identification" number imprinted on the sidewalls of all tires sold in the U.S. The DOT stands for the Department of Transportation, and the code ensures that the tire complies with federal safety criteria. This alphanumeric code, containing a series of 7 to 13 numbers, provides essential data about the tire's origin, size, manufacturer, and production date.
Why Is the Tire DOT Code Important?
The DOT code of a tire is important for drivers as it ensures product compliance with federal safety standards and helps motorists make informed decisions when buying tires (by avoiding purchasing aged tires). The DOT code is similarly important for manufacturers as they use it to identify recalled tires.
How to Read a Tire DOT Code
To read a tire DOT code, find the serial number containing eight to thirteen symbols following the "DOT" letters on the inside sidewall near the rim. The DOT code looks like in the example: DOTA34CXYZ4023 and is broken down as follows: the "DOT" abbreviation confirms the tire meets U.S safety standards, while the A3/ 4C/ XYZ identifies the manufacturing plant/ the size code/ the manufacturer code. The last four digits, i.e., 4023, show the production week and year (40th week of 2023 year).
| DOT Code Section | Meaning | Example |
| DOT | Certification that the tire meets U.S. safety standards | DOT |
| Plant Code | Identifies the manufacturing plant | A3 |
| Size Code | Indicates tire size specifications | 4C |
| Brand & Manufacturer Code | Specific to tire brand and manufacturer | XYZ |
| Date Code | Represents the week and year of manufacture | 4023 (40th week of 2023) |
Where Is the DOT Code Located?
The tire DOT code is typically found on the tire sidewall, inner or outer part, or both. When the code is printed on both sides of the sidewall, one side usually shows the partial code (DOT/ Plant/Size/Manufacturer Code), while the other side shows the full code (DOT/ Plant/Size/Manufacturer Code/Production Year+Week). Check the opposite side of the sidewall if you can't find the production date on one side.
How to Determine the Age of a Tire
The tire age is expressed in the last 4 numbers of the tire DOT code indicating the production week and year. The "DOTA34CXYZ4023" DOT code example shows that the tire was manufactured in the 40th week of the 2023 year.
Why Does Tire Age Matter?
Tire age matters because it helps drivers estimate the tire's lifespan and quality. Tire rubber tends to deteriorate over time (cracking, brittleness, change of color, deformation), even if used little or not at all. NHTSA recommends avoiding using tires for more than 6 to 10 years old, as the more they age, the more prone to failure they become, regardless of the treadwear.
U.S. Tire DOT Code Regulations
The Department Of Transportation and National Highway Traffic Safety Administration are the bodies that establish tire regulations in the U.S. Here are the main legal requirements for tires in the U.S.:
| Regulation | Requirement |
| DOT Code Requirement | All street-legal tires must have a DOT code imprinted on the sidewall. |
| Tire Age Limit | While there is no federal age limit, most manufacturers and experts recommend replacing tires within 6-10 years. |
| Tire Recall Compliance | Manufacturers must notify consumers and replace recalled tires free of charge. |
| Minimum Tread Depth | Federal law requires a minimum tread depth of 2/32 inches for safe driving. |
| Non-Compliant Tires | Tires without a DOT code cannot be legally used on public roads. |
What Is a Tire DOT Recall?
A tire DOT recall means that the manufacturer withdraws a specific batch of tires if it identifies certain issues and/or defects that can pose a threat to drivers' safety. The DOT code helps pinpoint which specific tires are defective based on their production data (manufacturing plant, manufacturer's code, production year). U.S. drivers can access the NHTSA website to check if their tires are part of a recall.
Are DOT Codes Required for All Tires?
Yes, all road-use tires sold in the U.S. must be DOT-certified. The only exception is racing and off-road tires, which are not intended for highway use.
Tire DOT Code: FAQ
How Do I Know How Old My Tires Are?
Find the last four digits of your tires' DOT code to determine their age. The sequence of four digits tells you the week and year of manufacture. For example, "4023" shows that the tires were produced in the 40th week of 2023. Based on this calculation, you can tell if your tires are aged if they are between 6 and 10 years old.
What If My Tire Doesn't Have a DOT Code?
Tires lacking a DOT code don't meet U.S. requirements and are therefore not legally approved for road use in the U.S. A road-use tire without a DOT code might be counterfeit and, due to its uncertified quality, put your safety at risk. Always buy tires from trusted manufacturers and dealers to ensure road safety.
The tire DOT code provides essential data for both drivers and manufacturers, ensuring safety and quality compliance. Every driver should check for tire age and recall status to make informed decisions about road safety.
NeoTires Helps You Stay Safe on the Road
Tire's DOT number is the key to ensuring your safety on the road. It might be the right time for a tire replacement if your DOT code shows more than 6-10 years. NeoTires makes it easy to find the right ties for your needs. Get in touch with our experts for personalized assistance! Drive safe and choose your tires wisely!
