In a recent crash test by the Insurance Institute of Highway Safety (IIHS), two plug-in hybrids – Toyota Prius Prime and Chevy Volt – earned the highest Top Safety Pick Plus designation, while Tesla’s Model S and the BMW i3 fell short.

To qualify for the IIHS’ Top Safety Pick, a car has to earn a rating of good in five tests – small overlap front, moderate overlap front, side, roof strength, and head restrains. The vehicle must also have an available front crash prevention system that earns a rating of advanced or superior. If a car meets the requirements and passes the assessments, it can earn the “Plus” moniker if its headlights are found to be good or acceptable, as explained in a video below.

With those criteria in mind, the IIHS reports that the Model S earned a rating of good in all of its evaluations, except for the small overlap front crash test, which simulates running into a narrow object. In that specific area, the sedan earned a rating of acceptable.

Other areas where Tesla’s sedan fell short include its headlights, which the IIHS rated as poor, having safety belts that didn’t prevent the crash dummy’s torso from moving forward, and not having hardware that allows the vehicles to make an emergency stop. As USA Today points out, not all Model S sedans built since last October have a front crash prevention system.

SEE ALSO: 2016 Toyota Prius and Prius Prime Look Good in Crash Test Ratings

The i3 also failed to obtain the institute’s highest ratings, as the electric car earned a rating of acceptable in the seat and head restraint evaluation.

Meanwhile, the two plug-in hybrid electric vehicles, the Chevrolet Volt and Toyota Prius Prime managed to impress the IIHS, with both being named as Top Safety Pick Plus cars.

According to USA Today, Tesla came out with a statement in regard to the Model S’ crash tests 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 has the lowest every probability of injury of any car ever tested by NHTSA.”

Tesla also told the outlet that it is continually working on updates for its vehicles, which will include new software that will allow its vehicles to brake automatically in an emergency situation in the near future.

USA Today, Insurance Institute for Highway Safety