What are you riding on?


Tires Expire in Six Years

Tires Expire in Six YearsThe evidence is clear: tires should have an expiration date.  Older tires are substantially more likely to fail than newer ones. This is because tires are made mostly of rubber, and rubber degrades with age. Sunlight, heat, ice, and general wear and tear can accelerate the breakdown of a tire. Once a tire begins to break down, it becomes more likely to fail in the form of a tread separation–often at highway speeds, when the failure is most likely to cause catastrophic injuries or death.

For most tires, this expiration date should be six years from the date of manufacture.  Tires age dangerously because of a chemical process commonly referred to as oxidation, which simply means that as the tire components are exposed to oxygen, the oxygen particles cause the flexible components of a tire to harden and become brittle. Over time, the tire will simply fall apart under normal stress, just like an old rubber band. Because this process occurs naturally, it does not matter if a tire is being used, stored as a spare, or simply waiting on a store shelf for an unsuspecting consumer. 1

In 1973, the average tread life of a passenger car tire was approximately 24,000 miles. Tire tread life has quadrupled over the last forty years and some currently sold tires promise 100,000 miles of tread life. As tread life becomes less of a factor in the service life of a tire, oxidation becomes a more serious concern— particularly in hotter climates, like Texas, Florida, Georgia, and Louisiana which are routinely the hottest states in the United States. 2

 

A Large Body of Scientific Literature Supports a Six Year Tire Expiration Date

Numerous studies written by or for the National Highway Traffic Safety Administration support a finding that tires expire in six years.

Numerous Studies have Concluded that Tires Expire in Six Years

These studies conclusively conclude the following:

 

Expired Tires are a Hidden Hazard

Tire aging is a “hidden hazard” because most consumers don’t know that tires expire in six years and it is difficult for most consumers to tell how old a tire is without deciphering an 11 digit code that is imprinted on the side of the tire. Fortunately, you can crack the code on the side of a tire to determine a tire’s actual age. You can either obtain a free Tire Facts Report from this website or you can do it the old-fashioned way.  Federal rules mandate that the tire’s D.O.T. code be clearly branded or etched on the side of each tire. 3 For most tires, the D.O.T. number is typically 11 digits. If the tire has only 10 digits, the tire was manufactured before the year 2000. A current D.O.T. number looks like this for a tire made in the fifth week of 2011:

How to Read TIRE DOT Number

To view the Tire Safety Group’s Guide on Locating and Interpreting a DOT code, click here

As you can imagine, most consumers either do not know that this code exists or do not understand its significance. A 2006 survey showed that only 4% of consumers are aware that tires become more dangerous as they age. 4 A large body of scientific evidence supports that most tires should be replaced six years from the date they are manufactured. 5 This six-year expiration date begins from the day the tire was manufactured at the plant—not the date it was sold to a consumer or the date that it was installed on a vehicle.

 

Tire Manufacturers Warn that Tires Expire in Six Years

Many auto manufacturers have taken small steps to warn consumers by placing warnings within the owner’s manual of newer model vehicles. However, due to the cryptic code tire manufacturers use on tires, the warnings are of only limited use to consumers. Nonetheless, the following manufacturers have issued warnings on 2013 and newer vehicles about tire aging:

Ford. GM, Toyota, Dodge, BMW, and other advise that tires expire in six years

Sadly, these warnings are not retroactively provided to consumers who own older model vehicles that are more likely to have aged or expired tires.

 

Check Your Tires for Free at Tire Safety Group

The Tire Safety Group offers a free tool for consumers to check their tires to instantly determine whether a tire is expired or recalled. Simply type in the full DOT code from your tire and instantly receive a free Tire Facts Report. Mobile users can even download the free Tire Facts iPhone/iPad app to check tires on the go.

Tire Facts iPhone App


by: Matt Wetherington

Matt Wetherington - Georgia Consumer Safety Attorney Circle

Notes:

  1. W. H. Waddell, “Halobutyl Rubber Innerliners on Tire Performance,” presented at the International Rubber Conference, Beijing, China, September, 2004; Baldwin, John M.,“Rubber Oxidation and Tire Aging – A Review,” February 2008.
  2. Data compiled from U.S. National Oceanic & Atmospheric Administration Earth Science Research Laboratory, http://www.esrl.noaa.gov, January 8, 2013.
  3. Transportation Recall Enhancement, Accountability, and Documentation (TREAD) Act (PDF here)
  4. Cowley, Jennifer, Kim, Soyun, and Wogalter, Michael, “People Do Not Identify Tire Aging as a Safety Hazard,” presented at the Proceeding of the Human Factor and Ergonomics Society 50th Annual Meeting, 2006.
  5. U.S. Department of Transportation, National Highway Traffic Safety Administration, DOT HS 810 799, Research Report to Congress on Tire Aging, August 2007. (PDF here)