9 Investigates: Some experts say date on tire age code is very important

CHARLOTTE, N.C. — In a 9 investigation, Eyewitness News found some stores selling new tires that were actually up to six years old.

Each tire has a code on it that will tell you when it was made. Some experts say that date is very important and that tires should not be used after a certain number of years.

The last four digits of the DOT code stamp on a tire indicate when it was made.

Some experts argue that tires over six years old could be dangerous and vulnerable to a catastrophic blowout, no matter how much tread is left.

You'd expect to find older used tires for sale.

Eyewitness News went tire shopping with our hidden cameras. At Discount Tire and Wheel in north Charlotte, Eyewitness News found a used tire for sale made 13 years ago, in 1999.

“Do you think the average person should know how to read these codes on the tires?” Eyewitness News anchor Scott Wickersham asked.

“Absolutely. And people who come in here and buy used tires from me, I show them where to find the age code,” said Bruce.

But what about new tires?

At the Walmart on Wilkinson Boulevard, Eyewitness News quickly found tires several years old being sold as new.

Then we spotted a code that made us look twice -- a tire that was made in the spring of 2006, and another made in summer 2006.

Both were over six years-old, being sold as brand-new.

“That tire should go back. That tire should be destroyed,” said vehicle safety researcher Sean Kane.

Kane said he's tracked hundreds of catastrophic failures in tires over six years old. He said tires begin to break down and weaken over time, especially if exposed to extreme heat, like there is in Charlotte.

“We’re not saying every tire will fail in six years, but you increase the risk of catastrophic belt separation once it reaches that point simply because of the material degradation,” he said.

Eyewitness News found what may be evidence of that type of aging on a four-year-old tire being sold as new on clearance at a Walmart in Matthews. You could see the drying and cracked, discolored rubber.

Kane said to watch out for tires sold on clearance. He said age could be the reason they're marked down.

At the BJ's warehouse in Pineville, Eyewitness News found two tires five years old being sold as new.

Kane has been fighting for restrictions on the sale of older tires, but the industry argues age isn’t everything.

“There is no data that says a tire won’t perform simply because it’s reached a certain age,” said Dan Zielinski with the Rubber Manufacturers Association.

Zielinksi said there are many factors like storage, use and maintenance that also come into play.

But he admits customers aren't getting their best deal when buying older tires.

“In many cases, you are getting older technology,” he said. “That’s just not a good practice for a retailer.”

But it’s not against the law.

That's why Kane suggests you learn how to the read the code.

After Channel 9’s investigation, Walmart admitted it sells older tires on clearance but said they are safe.

BJ's said it doesn’t cycle its inventory to keep newer tires in stock.

The National Highway Traffic Safety Administration has been investigating the issue. A spokesperson said they could have a decision later this year.

To find the age code on tires, look for the DOT number on the side wall. The last four digits show the week and year it was made.

WSOC