The two models did not fail any of the crash tests, but did fall short of meeting all the criteria needed to be rated a "Top Safety Pick" by the IIHS.
For the Model S, one crash test where the electric car did not get the highest rating of "Good" was the small overlap front crash where it was given an "Acceptable" rating by the IIHS.
In that test, the IIHS says the Model S safety belt allowed the dummy's torso to move too far forward so the dummy's head hit the steering wheel through the airbag. The IIHS also raised concerns about potential leg injuries for drivers involved in small overlap front crashes.
"Neither of these (potential injuries) were so high that we would expect life threatening injuries, but they are too high in our opinion to get "Good" ratings for those body regions," said Dave Zuby with IIHS.
Tesla believes the tests do not reflect the safety record of the Model S.