The US Department of Transportation and most manufactures recommend investing in new tires every five to six years with the maximum useful service lifetime of a tire being no more than 10 years.
This is not an issue that just impacts passenger vehicles; even large, industrial size tires on trucks, wreckers, tractors and more have a limited lifetime that is based more on when the tire was manufactured rather than how often it has been used. This means that even though a wrecker or truck may not see a lot of time or distance on the road, the tires are still deteriorating. This is why DOT date codes are vital in determining the health of your tires.
What is a DOT Date Code?
DOT date codes can be found on all commercially purchased tires, allowing you to keep track of the age of your tires and help determine how close they are to requiring a replacement. Because tires deteriorate over time and not just due to usage, knowing the age of tires is vital. The date codes also help in determining whether the tires have sat in storage when purchasing a new set. Additionally, understanding how the date codes work can help recognize why an incident may have occurred on a customer's tires and offer them a solution.
How to read DOT Date Codes
All DOT date codes can be found on the side of every tire. The code itself is made up a numbers and letters and will all be clearly marked with “DOT.” The remaining characters will outline the week and year the tires were manufactured, where the tired was made, the tire’s size as well as a unique manufacturers code.
The final four digits of the code are the most important as they contain the age of the tire, outlining the week and year the tires were made. For example, if the final four digits of the code read “3217”, the tire was manufactured in the 32nd week of 2017.
Prolonging the Life of Your Tires
While it is recommended that all tires, commercial and industrial, be replaced between six and 10 years after the manufacturers date, some additional methods can be taken to keep tires healthy and efficient. Whether or not they are on or off the vehicle, properly storing the tires away from the elements or extreme temperatures can help extend the life of your tires.
It is also highly recommended that any tire over five years old be visually inspected regularly. Watch for any wear on the tread of tire while keeping an eye out for whitening rubber or hairline cracking on the tire’s sidewall.