What must be present on a tire to indicate it complies with federal standards?

The presence of the letters "DOT" on a tire signifies that it meets federal safety standards set by the Department of Transportation (DOT) in the United States. This marking is essential because it indicates that the tire has undergone testing and meets the requirements outlined in federal regulations, ensuring that it complies with safety, performance, and quality standards.

The "DOT" marking is often accompanied by additional information, such as a manufacturer identification code and the date of manufacture, which are helpful for tracking and safety recall purposes. However, the essential indicator of compliance that directly connects to federal standards is the "DOT" designation. This helps ensure that tires on vehicles are not only safe for use but also suitable for various conditions and driving environments.

The other options may relate to safety or performance in different ways but do not specifically indicate compliance with the mandated federal standards in the same manner as the "DOT" marking.