The Insurance Institute for Highway Safety found that half of a dozen popular small cars tested for how they would stand up to a crash did not fare well.

Six of the cars tested, most of which were 2013 models, were rated “poor” or “marginal”.

General Motors Co’s Chevrolet Sonic and Cruze each received marginal scores, while Kia Motors Corp’s Soul and 2014 Forte were rated “poor” in the results released Thursday by the IIHS.

Nissan Motor Co’s Sentra also got a poor rating, while Volkswagen AG’s Beetle was ranked “marginal”.

Two redesigned Honda Civic models, the 2-door and the 4-door, were the only small cars to get the top rating in stringent front-end crash tests performed by the insurance industry group.

In the worst cases with the small cars that did not score well, safety cages collapsed, driver airbags moved sideways and the crash dummy’s head hit the instrument panel, and side curtain airbags did not deploy or provide enough protection, IIHS chief research officer David Zuby said.

Of the 12 models tested, the Kia Forte fared the worst, the institute said in a press release. Its seat belt allowed too much slack, and the side curtain airbag deployed but didn’t provide enough protection. The crash dummy’s head hit the windshield pillar and instrument panel.

In the test of the VW Beetle, the steering column moved nearly 5 inches to the right as the test dummy’s upper body moved forward and to the left.

“The rotation meant that the dummy’s head barely contacted the front airbag,” the institute reported.

“At the same time, the safety belt spooled out too much, allowing the dummy to move forward 13 inches and hit its head on the dashboard. The side airbag didn’t deploy.”

By comparison, the Civics sustained only minimal intrusion into the occupant compartment, providing “survival space for the dummy”, which remained well-protected from impact.

The IIHS increased the rigor of its tests last year to include crashes that involve only a front corner of a vehicle. The insurance group said nearly a fourth of U.S. front-of-vehicle crashes that result in serious injury or death involve only a single corner that strikes another vehicle or an object like a tree or utility pole.

The IIHS continues to score vehicles on side, rear, rollover and front-end crashes that impact more than just a corner.

“This is a challenging new crash test and it’s not surprising that some vehicles are earning marginal and poor ratings,” IIHS spokesman Russ Radar said of the small overlap front crash test.

“This crash scenario doesn’t lend itself to a Band-Aid fix so for most manufacturers the countermeasure will have to be built in when there’s a full redesign,” he added.

Vehicle manufacturers in the U.S. market often design and engineer their models to score well on IIHS safety tests and use the results in their marketing.

“It matters because in today’s world cars are so competitive that all you need is a small flaw and your competition can exploit it,” Kelley Blue Book senior analyst Karl Brauer said.

Most of the 12 small cars tested were already in production before the IIHS increased the rigor of its front crash test last year. However, Radar said IIHS alerted the companies to the work the group was doing on small overlap research in 2009.

The specifications of the test were not finalized until the last year, which is late in a car’s development process, Karl Brauer said. All automakers will eventually redesign their cars to meet the standards to pass the new crash test, he said.

Six of the 12 small cars tested by Insurance Institute for Highway Safety were rated poor or marginal

In the tests, IIHS crashes a vehicle at 40 mph into a 5-foot-high barrier on the driver’s side that overlaps one-quarter of the vehicle’s width.

Kia pointed out that the IIHS small overlap crash test goes well beyond federal requirements and the group has recognized numerous Kia vehicles as top safety picks. The South Korean automaker said it would evaluate the results carefully, but the company was proud of its safety record.

GM said customer safety remains its highest priority and it is committed to its cars performing well in all types of crashes.

“We are aggressively working to incorporate these into our models, including our small cars like the Chevrolet Sonic and Cruze, where technically feasible,” GM spokeswoman Sharon Basel said in an email.

Nissan and VW said they were proud of their cars’ safety records in federal crash tests and other IIHS crash tests, but they would review the small overlap test results and incorporate what is learned into future designs.

The small car segment was the fourth group of cars rated using this new test, and most of the groups have fared equally badly.

Last summer, 7 of 11 luxury sedans evaluated rated “marginal” or “poor”, and 12 of 15 small SUVs tested also failed to score well in results released in May.

Family sedans scored the best, with only 5 of 18 scoring “marginal” or “poor” in results released last December.

As a group, the small cars fared worse than the mid-sized family sedans, but better than the small SUVs, IIHS said. Results on the new crash test for mini-cars will be released later this year.

The other six small cars tested included two-and four-door versions of Honda Motor Co Ltd’s Civic, which both received “good” ratings. The Civic was tested earlier this year and the results were released in March.

Receiving “acceptable” ratings were Chrysler’s Dodge Dart, Ford Motor Co’s Focus, Hyundai Motor Co’s Elantra and Toyota Motor Corp’s 2014 Scion tC.

All the cars scoring well received “Top Safety Pick +” ratings by the insurance trade group. Vehicles earning the institute’s award have received “good” ratings in the four traditional tests plus “good” or “acceptable” ratings in the small overlap test.

IIHS said it did not test the Toyota Corolla because the automaker plans to release a redesigned 2014 model this month.

The market for small cars is one of fastest-growing in the U.S. Automakers have made the cars quieter and more refined as people who want good gas mileage turn to compacts and subcompacts.

So far this year, Americans have bought more than 1.8 million new small cars, up 12% over a year ago, according to Autodata Corp.

“Manufacturers need to focus on the whole package,” said David Zuby, the Institute’s chief research officer, in a statement.

“That means a strong occupant compartment that resists the kinds of intrusion we see in a frontal crash like this, safety belts that prevent a driver from pitching too far forward and side curtain air bags to cushion a head at risk of hitting the dashboard or window frame.”

2013 IIHS CRASH TEST RESULTS:

Good/acceptable ratings:
Honda Civic 4-door
Honda Civic 2-door
Dodge Dart
Ford Focus
Hyundai Elantra
Scion tC (2014)

Marginal/poor ratings:
Chevrolet Sonic
Volkswagen Beetle
Chevrolet Cruze
Nissan Sentra
Kia Soul
Kia Forte (2014)

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