The Tesla Model S has received a five-star safety rating in every subcategory from the National Highway Traffic Safety Administration (NHTSA), making it part of the one percent of all vehicles tested by the federal government to achieve a perfect score.
While NHTSA does not publish a star rating above 5, safety levels better than five stars are captured in the overall Vehicle Safety Score (VSS) provided to manufacturers, where the Model S achieved a new combined record of 5.4 stars.
Tesla says the Model S set a new record for the lowest likelihood of injury to occupants. While the Model S is a sedan, it also exceeded the safety score of all SUVs and minivans, which takes into account the probability of injury from front, side, rear and rollover accidents.
The lack of a large gasoline engine block in the front creates a much longer crumple zone to absorb high-speed impacts, the company claims. The longer the crumple zone, the more time there is to slow down occupants at g loads that do not cause injuries. The Model S motor is only about a foot in diameter and is mounted close to the rear axle, and the front section that would normally contain a gasoline engine is used for a second trunk.
Tesla says the Model S was the only car in the "good" category for the side pole intrusion test among the other top one percent of vehicles tested. Compared to the Volvo S60, which is also 5-star rated in all categories, the Model S preserved 63.5 percent of driver residual space versus 7.8 percent for the Volvo. Tesla claims it has achieved this outcome by nesting multiple deep aluminum extrusions in the side rail of the car that absorb the impact energy —a similar approach was used by the Apollo Lunar Lander — and transfer the load to the rest of the vehicle. This causes the pole to be either sheared off or to stop the car before the pole hits an occupant.
To address the rear crash test, Tesla says it installs a double bumper if the third-row children’s seat is ordered. This was needed in order to protect against a highway speed impact in the rear, significantly reducing the chance of permanently disabling injury to the third-row occupants.
The Model S also received top ratings in rollover risk, according to Tesla. During testing at an independent facility, the Model S did not turn over via the normal methods and special means used to induce the car to roll. Tesla says thefact that the battery pack is mounted below the floor pan, providing a very low center of gravity, simultaneously ensures exceptional handling and safety.
During validation of Model S roof crush protection at an independent commercial facility, the testing machine failed at just above 4 g's, Tesla says. What this means is that at least four additional fully loaded Model S vehicles could be placed on top of an owner's car without the roof caving in, which is achieved primarily through a center (B) pillar reinforcement attached via aerospace grade bolts.
In June, Tesla introduced a new system that allows battery packs in electric vehicles to be swapped in roughly 90 seconds. The system provides an alternative to charging EVs that the company says may help to convince consumers they are more convenient than a gasoline car.