What can excessive frame rust lead to?

Excessive frame rust can lead to compromised structural integrity and safety hazards because it deteriorates the metal and can significantly weaken the frame of a vehicle. The frame is a critical component that supports various parts of the vehicle and ensures stability and safety while driving. When rust sets in, it can create weak points that may fail under stress, leading to potential accidents or catastrophic failures. This highlights the importance of regular inspections and maintenance to address any signs of rust early before they escalate into more critical issues.

The other options do not accurately reflect the consequences of excessive frame rust. Improved aesthetic appeal, better fuel efficiency, and increased resale value are not outcomes associated with rust; in fact, rust tends to detract from these aspects, making it a significant concern for vehicle owners.