Which component is not part of a Class D inspection?

A Class D inspection primarily focuses on safety components that ensure the vehicle is roadworthy and compliant with regulations. These inspections typically include checks that relate directly to the vehicle's operational safety and visibility.

Given this context, evaluating engine oil is not a part of a Class D inspection. While engine oil condition is important for the overall health of the vehicle, it falls outside the scope of the specific components and safety checks that are emphasized during a Class D inspection. This inspection is more concerned with the immediate aspects that affect driving safety, such as tire conditions, brake performance, and visibility through mirrors. Each of these elements plays a crucial role in ensuring that the vehicle can be safely operated on public roads.

In contrast, tire condition checks, brake performance assessments, and mirror visibility checks all directly relate to safety measures that prevent accidents and ensure compliance with traffic regulations, making them integral to the inspection process.