What force-to-weight ratio in a roof strength rating test results in a poor rating?

In the context of roof strength rating tests, a force-to-weight ratio of 4:1 indicates that the roof can support four times its own weight. This level of strength is considered insufficient for a good rating in safety standards. A roof strength rating reflects how well a vehicle can withstand loads, particularly in rollover accidents, where the integrity of the roof is critical for occupant protection.

A ratio lower than 4:1 indicates that the roof may not provide adequate protection, which is why it receives a poor rating. In contrast, higher ratios, such as 5:1, demonstrate better strength and structural integrity, ensuring that the vehicle’s roof can handle greater forces without compromising safety.

Thus, a 4:1 ratio clearly indicates a concern regarding vehicle safety and occupant protection, making it a poor rating in roof strength tests.