Which of the following is NOT a cause of vehicle fires?

Properly sealed cargo is not a cause of vehicle fires. In fact, ensuring that cargo is properly sealed and secured can help prevent incidents that may lead to fires, as it reduces the risk of spillage or leaks that could result in flammable materials coming into contact with heat sources. When cargo is well-packaged, it often includes precautions against issues that could be fire hazards.

In contrast, underinflated tires can lead to excessive heat build-up and friction, increasing the risk of a fire due to tire failure. Driver smoking is a well-known risk because discarded cigarettes or matches can easily ignite flammable materials inside the vehicle. Spilled fuel can create a hazardous situation, especially if it comes into contact with hot engine components or electrical sparks, leading to a potential fire. Thus, choosing properly sealed cargo emphasizes the importance of cargo management in preventing fire hazards.