5 of 12 Get Marginal Ratings in First IIHS Rollover Tests of Midsize SUVs

In the first Insurance Institute for Highway Safety (IIHS) roof strength tests of midsize SUVs, the results were somewhat satisfactory, though there still are some improvements to be made. Six vehicles earned the top rating of good for rollover protection, one got the acceptable rating, while five others earned the second lowest rating of marginal.

"Midsize SUVs are a big group so we're testing them in stages," IIHS president Adrian Lund said in a release. "First results show that automakers are making progress in rollover protection, but it's disappointing that a new design like the Crosstour didn't perform better."

During its rollover tests, the IIHS uses a metal plate that is pushed against one corner of a roof at a constant speed. To earn a good rating, a roof must withstand a force of 4 times the vehicle's weight before reaching 5 inches of crush, while a marginal rating value is 2.5.

When vehicles roll, their roofs hit the ground, deform, and crush. However, the best occupant protection is to keep vehicles from rolling in the first place.

Taken separately, let’s see which midsize SUVs are the most reliable if you happen to get involved in a rollover crash: the 2010 Chevrolet Equinox (and twin GMC Terrain) built after March 2010, Jeep Liberty (twin Dodge Nitro), Toyota Highlander and Venza, plus the Jeep Grand Cherokee and Kia Sorento, both 2011 models.

The 2010 Ford Edge was the one rated acceptable. The worst performers, which earn marginal ratings, are the Honda Accord Crosstour, Honda Pilot, Mazda CX-7, Mitsubishi Endeavor, and Nissan Murano, all 2010 models.