Tesla Motors Inc.’s 2017 Model S and BMW Group’s 2017 i3 electric vehicles failed to qualify for the Insurance Institute for Highway Safety’s Top Safety Pick award.

The group said Wednesday that the Model S received good ratings in all evaluation areas except the small-overlap front crash test, which the group said is a “challenging” test for which the Tesla only earned an acceptable rating. The small-overlap test — added in 2012 — replicates what happens when a vehicle runs off the road and hits a tree or pole or clips another vehicle that has crossed the center line. In the test, 25 percent of the total width of the vehicle hits a 5-foot-tall rigid barrier on the driver side at 40 miles per hour.

The 2017 BMW i3, meanwhile, earned good ratings in all of the group’s criteria except the tests for head restraint and seat evaluation, which the group said measures a vehicle’s ability to protect against neck injuries in a rear crash. The IIHS rated the i3 acceptable in the head restraint test.

The group, which represents the insurance industry, measures crashworthiness in five areas — small-overlap front, moderate overlap front, side, roof strength and head restraint. To receive a Top Safety Pick designation, vehicles must earn a good rating in all five areas, and also be equipped with a front-crash prevention system rated as advanced or superior. The Top Safety Pick Plus award goes to vehicles that meet all of those criteria and also have good or acceptable headlights.

David Zuby, IIHS executive vice president and chief research officer, said the insurance group hopes Tesla and BMW will make improvements.

“There’s no reason the most efficient vehicles can’t also be among the safest,” Zuby said in a statement. “We hope Tesla and BMW will continue to refine the designs of their electric models to maximize driver protection and, especially in the case of Tesla, improve their headlights.”

The Tesla’s headlights were rated poor.

The IIHS noted that a pair of hybrids, the previously tested 2017 Chevrolet Volt and the Toyota Prius Prime, received the Top Safety Pick Plus award. The Prius Prime is the plug-in version of the regular Prius hybrid, previously a Top Safety Pick Plus winner.

The group noted that Tesla and BMW have attempted to improve safety of the cars.

“Despite lengthening the side curtain air bags to improve small overlap protection in the Model S, Tesla ran into problems in the test when the safety belt allowed the dummy’s torso to move too far forward,” it said. “That allowed the dummy’s head to hit the steering wheel hard through the air bag. Measurements from the dummy indicated that injuries to the head, along with the lower right leg, would be possible in a real-world crash of the same severity.”

Tesla defended the safety of its Model S, saying: “We are committed to making the world’s safest cars, and Model S has previously received a 5-star safety rating from the National Highway Traffic Safety Administration and a 5-star rating from Euro NCAP. Model S still has the lowest ever probability of injury of any car ever tested by NHTSA.”

The company added: “We proactively develop updates and aggressively implement changes onto the production line in record time any time there is a substantial benefit to customer safety. One of the improvements recently introduced in January 2017 specifically addresses the ‘Acceptable’ (or second-highest) rating that the Model S achieved in the small overlap frontal crash test, and we expect new tests to yield the highest possible rating (‘Good’ rating) in the crashworthiness category.”

Zuby added of the i3: “BMW clearly thought a lot about safety when designing the i3. It’s a shame that it missed the mark on head restraints, which is something most of today’s vehicles get right. Among small cars, the i3 is the only 2017 model that doesn’t get a good rating.”