We bought one for $20 at Solo Tires on South Saunders Street in Raleigh, and later took it back to Carlos Maldonado - who sold it to us.
We asked him if he thought it was a safe tire to sell.
"Not really. It's really wear from right here. Really messed up already," he said.
Maldonado admitted the tire wouldn't pass a state inspection, but said his customers know what it means to buy used.
"The people know what exactly they're buying," he explained. "They're buying. They should know what they're buying. They're used tires."
We took the tire to Dan Zielinski, who's with a trade group that represents tire makers called the Rubber Manufacturers Association.
"A tire like this is very dangerous," he said. "This is the belt edge area of the tire and it also should never be repaired in the sidewall of the tire. The other way it's been improperly repaired is that this is what they call a plug-only repair."
Driver Kelly Burden says she learned her lesson about used tires the hard way after getting into a crash.
"I didn't realize ... to think you know, that's your life," she said.
Burden had used tires on her SUV when a tire blew out on a Florida highway.
"Tires are a critical safety component on your vehicle. They're the only part of your vehicle that touch the road," Zielinski explained.
The I-Team also bought a used tire at the Blue Flame Tire Center on Raleigh's Capital Boulevard. Zielinski said the $30 tire has problems.
"You can see, especially on this side, almost chunks of the tire have come out," he explained. "This is a tire that shouldn't be placed back into service. It also pretty much reached the end of its tread life as well.
Jerry Culbreth owns Blue Flame. He told us he doesn't share Zielinski's concern about the tire.
"You'll see this on most any tire, depending on where it's been driven at. The tire's not dry-rotted. It appears to be in good shape at the sidewalls. So I think that the tire would probably be safe," he said.
We asked Culbreth if he would use the tire on his vehicle.
"If I needed a used tire, yes," he said.
Asked if he would be comfortable with his family driving on a used tire, Culbreth said: "If my family was in this vehicle, I would hope that I could get new tires."
Culbreth says he has about 40,000 used tires and believes buying used is a good way to save money.
"We have more used tires here than probably anyone in the state. So we take that responsibility seriously," he offered.
And Cubreth says the tires are scrutinized before they're sold.
"That's right. Yes, we do. We definitely try to. Once we have, you know, picked it out, now it's on the wheel, we balance it, run it through the water, make sure there's no leaks. We also inspect the sidewalls to make sure there's no splits," he explained.
Back at Solo tires, Maldonado took us inside and showed us he has plenty of higher quality tires that sell for 30, 40, and 50 dollars. But he made no apologies for selling us a worn-out $20 tire.
"Don't you have a responsibility, Carlos, as a businessman to sell tires that are in good condition?" we asked.
"Like I said, I just work here. The boss is the one that gets the tires. So I'm just doing my work, trying to sell the tires," Maldonado responded.
Zielinski's group - the Rubber Manufacturer's Association would like to see laws passed that would ban the sale of unsafe used tires.
Experts say there's an easy way to check the tread on your tires anytime. Do the "penny test". Turn a penny upside down in the tread. If you can see all of President Lincoln's head, then it's time for new tires.