The test mimics a crash where just the front corner of the vehicle hits another car, tree or telephone pole.
"In this type of crash, we see lots of intrusion in the occupant compartment if it's not strong enough. And sometimes, because of the off center forces, we see movement of the occupants inside that are a challenge for the restraint systems," said David Zuby with the IIHS.
Unfortunately, many of the bestselling small cars did not do very well in the tests. Six of the 12 models evaluated earned marginal or poor ratings. Those include the Chevrolet Sonic, Chevrolet Cruze, Volkswagen Beetle, Nissan Sentra, Kia Soul and the Kia Forte.
"The Kia Forte was the worst performer among the small cars we recently subjected to our small overlap crash test. Horrendous collapse of the occupant compartment illustrated by collapse of the hinge pillar, footwell, A-pillar instrument panel all coming in toward the driver," said Zuby.
On the other hand, the Dodge Dart, Ford Focus, Hyundai Elantra, and the 2014 Scion TC earned acceptable ratings. Only 2-door and 4-door models of the Honda Civic earned the top rating of "good" in the test.
"They earned their good rating because their structures held up and didn't collapse in on the driver. The steering column was stable, so the driver airbag was able to protect the head and the chest of the driver," said Zuby.
These latest test results show how some automakers are designing safer cars, which is good to know, while other automakers have more work to do, which is not so good.