Monday, June 30, 2008

NHTSA Consumer Advisory: Old Tires Can Be Just As Dangerous As Bald Tires, Regardless Of Tread Condition

This tire has never been used. It easily passes the "coin test". Yet it could be unsafe; it was manufactured 14 years prior, and is being sold as "new".

We are all aware of the hazards of bald tires; most of us know about the "coin test" to determine if your tread is reaching hazardously low levels.

But did you know that old tires can be dangerous as well? Old tires can catastrophically fail at freeway speeds, even if there is still ample tread. The problem is serious enough to have prompted the National Highway Transportation Safety Administration (NHTSA) to issue an advisory on June 2nd, 2008. A report posted on initially alerted me to this problem, but further research led me to a story by MSNBC. also offers useful information.

Recently it has been disovered that tires older than six years, whether still on a vehicle or just bought in a store and installed on a vehicle, can easily self-destruct at highway speeds. You will not see the failure coming as this is taking place inside the tire. It is a myth that tires are not defective until cracks in the rubber appear. Tread can separate from the tire causing catastrophic failure. Tires dry out, and with today's rubber there may not be any visible signs a failure is happening until a fatal accident occurs. According to a recent government report discussed on MSNBC, 84 percent of insured tire claims examined from a number of states involved tires that were more than six years old. A research video showed a tire that had been artificially aged to six years disintegrating under the load of a moving car.

Even worse, investigative reporters found that Sears, Walmart and other well known stores frequently have OLD tires on the shelves being sold as new. It's still currently legal to sell these tires because there are no expiration dates established by any government, whether it be the United States or the UK. And while our Walmarts in Alaska don't sell tires, Sam's Club, which is part of the Walmart family, does sell tires.

But we're not completely screwed. Even though expiration dates are not stamped on tires, manufacture dates are available. The Rubber Manufacturers Association gives us a complete decode on all the information stamped on a typical tire. And the date of manufacture is appended to the tail end of the DOT Tire Identification Number, which is shown on the illustration below:

The manufacture date will either be the last three numbers (tires made in 1999 or earlier) or the last four numbers (tires made in 2000 or later). Obviously, you do NOT want to buy any tires made earlier than 2000, so I'll just decode the post-2000 date. The first two digits indicate the numerical week, the last two digits are the last two digits of the year. Example: 2402 indicates the tire was manufactured during the 24th week of 2002.

The bottom line: If you commute regularly, or even drive at highway speeds periodically on a road trip, avoid buying tires that are more than six years old, even if they've never been used. Ask the dealer from who you buy the tires to make sure the tires are less than six years old.


  1. Thanks for the info! Car owners really need to check their tires regularly to ensure their safety.

  2. The information about the coin test in tires to determine its hazardous level is really a helpful check. The danger of an old tire is the same as the bald one. The most important thing here is that car owners must realized the importance of having a good set tires and rims. It is also recommended to have its regular check, like tire rotation and tire fitting to avoid any problem and accidents.

  3. Such a wonderful post about tires.