While second-hand tires are frequently much cheaper than new ones, there are considerable safety risks associated with used tires that make them a poor choice, according to consumer advocacy website Consumer Reports. Wear and damage on used tires may be difficult to detect before purchase.
Used tires are subject to a number of potential sources of wear that may render them unsafe for use. In addition to the normal wear associated with use, used tires may be damaged in accidents or by incorrect mounting and removal procedures. While it is possible to judge the wear on a tire by its treads, damage to the interior of a used tire is often difficult to detect.
Even undamaged tires undergo a process of degeneration as they age that may render them unsafe to drive on. All tires have a Department of Transportation code that is capable of identifying the date of manufacture of the tire. Tire aging is not always visible, so it is important to determine how old a set of used tires is to avoid purchasing tires that have aged past their useful life. Many tire manufacturers recommend replacing tires that are over 10 years old, while automakers often recommend replacement after six years.