DETROIT – Two redesigned Honda Civic models were the only small cars to get the top rating in stringent front-end crash tests performed by an insurance industry group.

In all, half of the 12 compact and subcompact cars tested by the Insurance Institute for Highway Safety fared poorly, but six performed well. Safety is critical in the fast-growing small-car market, with many buyers downsizing from larger vehicles.

The two-door and four-door Civics earned "good" ratings, while the Dodge Dart, Ford Focus, Hyundai Elantra and the 2014 Scion tC were "acceptable."

But popular models such as the Chevrolet Cruze and Sonic and the Volkswagen Beetle got "marginal" ratings, while the Nissan Sentra and the Kia Soul and 2014 Kia Forte each were rated "poor."

The group didn't test the Toyota Corolla because a new version is coming out in the fall. The Corolla is the No. 2 selling small car in America, behind the Civic.

The cars were rated for their performance in the insurance institute's "small overlap" test of crashes that cover only 25 percent of a vehicle's front end. These tests, added to the IIHS' evaluations last year, are forcing automakers to bolster the front-end structure of all cars.

The IIHS tests are more stringent than the U.S. government's full-width front crash test. The institute says that in many vehicles, a crash affecting one-quarter of the front end misses the main structures designed to absorb the impact. Yet such crashes account for nearly a quarter of the frontal collisions that cause serious or fatal injuries to people in the front seats, IIHS says.