In another setback for the high-flying electric carmaker, Tesla's Model S once again fell short of the top rating in a key crash test, an independent testing agency said Thursday.
On the eve of seeing its first mass-market Model 3 roll off the assembly line, the Insurance Institute for Highway Safety said that despite changes made to the vehicles produced after January, the Model S was again only able to attain an acceptable rating in the small-overlap test conducted in February. That test mimics a car hitting a tree or a pole.
As a result, Tesla failed to achieve the IIHS Top Safety Pick rating, which requires a "good" rating in all five of its crash test scenarios. Carmakers often request a retest if they fall short of the highest rating the first time.
IIHS said the Model S in both tests fell short of the top rating because the safety belt did not sufficiently restrain the driver in the crash.
"The main problem with the performance of the Model S was that the safety belt let the dummy's torso move too far forward, allowing the dummy's head to strike the steering wheel hard through the airbag," the statement said.
The vehicle also had some structural issues in the second crash test, IIHS said.
Tesla in April recalled 53,000 vehicles to address a manufacturing defect that could prevent the parking brake from releasing, but there were no reports of injuries or accidents related to the issue.
The company also was investigated for a fatal crash in May 2016 involving a driver of a Model S using the Tesla's autopilot feature. But investigators found the driver was warned repeatedly for not keeping his hands on the steering wheel, and no safety defect was found.