What does a tire worn on the outer edges typically indicate?

A tire worn on the outer edges typically indicates that the tire is under-inflated. When a tire lacks sufficient air pressure, it causes the outer edges to make more contact with the road than the center, leading to uneven wear. Under-inflation reduces the tire's overall performance and can result in increased risks of blowouts and reduced fuel efficiency.

In contrast, over-inflation would typically lead to more wear in the center of the tire rather than the outer edges. Uneven weight distribution might cause varied wear patterns but would not specifically lead to outer edge wear. Lastly, while tires do have a lifespan, the specific sign of outer edge wear is more directly linked to under-inflation rather than simply aging or nearing the end of their usable life. Understanding these wear patterns is crucial for maintaining tire safety and performance in tractor-trailer operation.