Car owners who purchase used tires may do so because they are often considerably less expensive than new ones. Additionally, if a tire is damaged, it may be expedient to buy a used one and replace the entire set later.
In addition to looking for signs of improper repair or aging, used tires should be thoroughly inspected prior to purchase. Using a penny, check the tread depth to ensure it is not legally bald. Then, look at the tread surface and sidewalls for irregular wear, bumps, waviness, irregularities and visible cords or wires, as these indicate a dangerous tire. Next, look for damage to the rings of rubber where the tire contacts the wheel that can prevent the tire from properly sealing. Finally, check the tire's inner liner for damage or exposed cords.