When it comes to keeping tires up to spec, NMA members are second to none. They know the safety and performance benefits of maintaining proper tire inflation, not to mention routine tire inspection, rotation and balancing.
So, we wanted to discuss an important tire safety concern that many may not be aware of: old tires being passed off as new.
As tires age, the rubber compounds dry out and break down. This increases accident risk due to tread separation. ABC News covered the serious nature of these accidents a few years back. And while the report may sensationalize aspects of the story, the overall point is an important one: You need to be careful when shopping for tires since looks can be deceiving.
An old, unused tire looks just like a new, unused tire, and some retailers have been caught selling “new” tires that are actually 8-10 years old. Tires that are exposed to UV rays break down even quicker so beware of tires that have been stored outside.
We have not seen any studies that have determined average tire shelf-life, but experts generally agree that any tire six years or older should be discarded, even if it has never been on the road. NHTSA offered the following guidance:
While tire life will ultimately depend on the tires’ service conditions and the environment in which they operate, there are some general guidelines. Some vehicle manufacturers recommend that tires be replaced every six years regardless of use. In addition, a number of tire manufacturers cite 10 years as the maximum service life for tires. Check the owner’s manual for specific recommendations for your vehicle. Remember, it is always wise to err on the side of caution if you suspect your vehicle has tires that are over six years of age.
To tell how old a tire is look for the tire identification number which begins with the letters “DOT”. It’s typically found on the sidewall of the tire close to the rim. On older tires, the number may be on the inside sidewall, so you’ll have to crawl underneath the vehicle with a flashlight to find it.
The last four numbers in the sequence are the date code. The first two numbers indicate the week and the last two numbers indicate the year the tire was manufactured. In the photo below the date code is 3507 which means the tire was manufactured during the 35th week of 2007. Note that tires manufactured before 2000 use only one number for the year. Hopefully, you won’t run into any of those.
Make sure to check the date code on any tires you’re considering for purchase. It will help you determine overall tire life and whether or not you’re really getting what you’re paying for. For more information on the dangers of old tires look here.