What is considered a defect in a tire?

A tire defect is characterized by conditions that impair the tire's performance, safety, or longevity. Tread damage longer than 2.5 cm is indeed considered a significant defect because such damage can compromise the tire's structural integrity and its ability to maintain grip on the road. Tread is critical for traction and water displacement, and a cut or damage of this length can lead to increased risk of tire failure or a blowout. When the tread integrity is compromised, it affects the entire tire's performance, especially in adverse weather conditions, making it more hazardous for driving.

While shorter tread depth and other surface irregularities can be concerning, they typically indicate different maintenance needs rather than immediate defects affecting structural integrity. For example, while treads shorter than 2 mm can significantly affect traction, as they are nearing the end of their useful life, they don't represent an immediate risk in the same way that a significant tear or damage would. Similarly, uneven tire pressure, though it can lead to uneven wear and handling issues, does not classify as a defect in the tire itself, but rather an issue with maintenance.