Why is the Tire Identification Number (TIN) so important? I have addressed the issue of recalled tires, but there is another important factor in the TIN, and that is found in the last 4 digits. The last 4 numbers in a TIN represent the week and year the tire was manufactured. For example, with a TIN that is DOT XX 54 X00 2613, the last 4 numbers (2613) means this tire was manufactured in the 26th week of 2013. This date is important for recall tracking, as discussed in my previous article, but it is also important to understand the age of the tire. Most people do not realize that tires can both “wear out” and “age out.” The rubber in a tire degrades over time and can cause catastrophic failure that results in many of the fatalities associated with tire problems. The conditions the tire is used can also cause the tire to degrade over time especially when impacted by climate such as exposure to excessive heat. For example, a tire that should be replaced due to age after 10 years might need to be replaced sooner if installed on a vehicle in Arizona. Most of the major car manufactures recommend (in the owner’s manual) that a tire be replaced every 6 years, regardless of wear. Many of the tire manufactures stipulate that a tire has gone beyond its effectiveness after 10 years, regardless of any other factor, such as wear. This often-unknown factor adds a new wrinkle to tire safety—that tires need to be check for age as well as wear. The only way to do this is through the TIN. The need for replacement based on age is something not only most consumers are unaware of, but most service providers are foggy on this subject, too. A general awareness and the ability to capture and properly read the TIN are needed, so consumers can be informed of the health of their tires and make an informed decision for their safety. David Boyle is a 25-year industry expert and the CEO of Tire Profiles, the leading supplier of tire and alignment measurement solutions.