Tesla has long promoted its cars as among the safest available. After its Model S electric sedan was reviewed by the federal government’s National Highway Traffic Safety Administration in 2013, Tesla said it had received the best safety rating of any car ever tested.
But a more rigorous safety review has reached a different conclusion: that the Tesla S is not on a par with several of its luxury rivals.
On Wednesday, the Insurance Institute for Highway Safety, a group known for its strict testing, announced that the Tesla S did not receive either of its safety awards. That was, in part, because in one of five crash tests the dummy’s head hit the steering wheel.
To be a 2017 Top Safety Pick, a vehicle must have “good” ratings in five crash tests and have an “advanced” or a “superior” rating for frontal crash prevention, which includes automatic emergency braking if a collision is imminent. To receive the higher 2017 Top Safety Pick+ designation, a vehicle must meet all those criteria and get an “acceptable” or “good” headlight rating, which was added for 2017.
The Model S got an “acceptable” in the small overlap frontal, a test intended to replicate what happens when the front corner of a vehicle on the driver’s side hits another vehicle, a tree or a utility pole at 40 miles per hour.
The seatbelt was not tight enough, the institute found, allowing the crash test dummy’s torso to be thrown so far forward that its head hit the steering wheel through the airbag. The impact was hard enough that it could cause a concussion or facial fractures in a real crash, said David Zuby, the organization’s executive vice president and chief research officer. But there was not a “high risk” of serious injury.
“The seatbelt force limiter and airbag did not work together quite the way we think is good for this type of crash,” he said.
The car’s headlights were rated “poor.”
The insurance institute did not test the Model S’s forward collision prevention and automatic braking system because it bought the car before Tesla added new hardware and software in October.
Tesla made those changes after a man died in a crash in Florida in May when the Model S was using Autopilot, its driver-assistance system. This month, federal regulators said they found no defects in the system that caused the crash and that the vehicle did not need to be recalled.
On Jan. 23, Tesla made a change to address the head contact issue, Mr. Zuby said. The insurance institute will conduct a new small overlap test and will test the forward collision avoidance system when it receives a new vehicle with the changes.
Tesla says its Model S still has the lowest probability of injury of any car ever tested by the National Highway Traffic Safety Administration. And when the insurance institute gets its new Model S with modifications, Tesla says it expects “to receive the highest possible rating in every category, making Model S eligible for the I.I.H.S. Top Safety Pick award.”
The 2017 Model S was one of two all-electric vehicles the institute tested. The other, the BMW i3, narrowly missed one of the safety awards because its head restraints were rated “acceptable,” not “good.”
“Consumers might expect that luxury brand vehicles are safer, and in many cases they’d be right,” Mr. Zuby said. “But that’s not a hard and fast rule.”
The insurance institute recommended that people choose any of the seven other 2017 large luxury models that have fared better than the Model S. The Top Safety Pick+ rating went to the Genesis G90 and G80 models, made by Hyundai, and the Lexus RC. Four rated “Top Safety Pick” are the Acura RLX, Audi A6, Infiniti Q70 and Volvo S90.