Only three of seven midsize SUVs from the 2015 model year performed well in front-end crash tests done by an insurance industry group.

The Nissan Murano and Jeep Wrangler four-door got the highest, or "good," rating in the latest round of Insurance Institute for Highway Safety small overlap crash tests. The Ford Flex got the second-best "acceptable," rating in the test, which mimics what happens when a car's front corner collides with another vehicle or object such as a utility pole.

The Dodge Durango, Jeep Cherokee and Hyundai Santa Fe got "marginal" ratings, and the Dodge Journey received a "poor" rating on the test, in which 25 percent of a vehicle's front end strikes a barrier at 40 mph.

The test, instituted in 2012, is more demanding than the U.S. government's head-on frontal crash test. The institute uses its crash test scores to prod automakers into adding safety devices or making their cars more crash-resistant, especially as vehicles are redesigned.

The Murano, with a superior-rated system that automatically brakes the SUV when a front-end crash is imminent, earned the coveted IIHS "Top Safety Pick Plus" designation. To earn that, vehicles must get "good" ratings in four crash tests, "good" or "acceptable" in the overlap test, and they must have available a front crash prevention system that can brake the vehicle.

Ford's boxy Flex earned a "Top Safety Pick" rating, falling short of the "Plus" because it doesn't have automatic braking available.

The Jeep Wrangler, made by Fiat Chrysler, didn't win a "Top Safety Pick" because it offered only "marginal" side and rear crash protection, the institute said in a statement.

Of the seven SUVs tested in this round, the Fiat Chrysler's Dodge Journey was the worst performer. The passenger compartment failed to hold up in a crash, the parking brake pedal tore through the crash dummy's left lower leg, and the side air bag failed to inflate, the institute said. The Journey was introduced in 2009.

In an earlier test of nine midsize SUVs from the 2014 model year, the Toyota Highlander earned a "Top Safety Pick Plus" rating, while the Chevrolet Equinox and GMC Terrain made by General Motors got "Top Safety Pick" designations along with the Kia Sorento and Nissan Pathfinder.