IIHS Roof Strength Crash Test - Click above for high-res image gallery
The Insurance Institute for Highway Safety isn't waiting around for the federal government to enact tougher roof strength standards for passenger vehicles. The IIHS has created its own new category of roof strength standards that requires a strength-to-weight ratio of 4 times a vehicle's weight to earn the highest rating of good. Federal standards are currently 1.5 times a vehicle's weight, with a proposed increase to 2.5 times still pending.
The IIHS used a batch of 12 small SUV/CUVs as guinea pigs for the new standard, and only four were rated good: the Volkswagen Tiguan, Subaru Forester, Honda Element and Jeep Patriot. The Suzuki Grand Vitara, Chevrolet Equinox, Toyota RAV4, Nissan Rogue and Mitsubishi Outlander were rated acceptable with strength-to-weight ratios of at least 3.25. The Honda CR-V and Ford Escape achieved a marginal rating with scores of at least 2.5 and the Kia Sportage was rated Poor with a score below 2.5.
The IIHS roof strength crash test is conducted by pushing a metal plate at constant speed against one side of a vehicle's roof. In order to earn a good rating, a vehicle's roof must withstand a force of 4 times the vehicle's weight before reaching 5 inches of crush. Earning the roof strength test's highest rating will also be a new requirement for the Institute's Top Safety Pick awards. As a result, the list of winners for 2010 will likely be much smaller than last year's. Eight of the small SUV/CUVs tested by the IIHS were previous Top Safety Picks, but only three would earn the award with these new standards.
Gallery: IIHS Roof Strength Crash Tests
[Source: Insurance Institute for Highway Safety]