Tesla S gets best safety mark of any car ever tested

Tesla S

Tesla S

NEW NHTSA VEHICLE SAFETY SCORE RECORD SET

Broke Test Machine in Crush Test above 4 G’s

BY GERRY MILES

The folks at Tesla must be beyond happy to learn that their S received the highest ever 5-star test rating after independent testing by the National Highway Traffic Safety Administration (NHTSA) in every subcategory without exception. If they awarded a 6-star rating, they’ve had likely got a 10. However, Tesla notes that in the overall Vehicle Safety Score (VSS) provided to manufacturers, the Model S achieved a new combined record of 5.4 stars. The score takes into account the probability of injury from front, side, rear and rollover accidents.

The S, which is a sedan, also topped the safety score of all SUVs and minivans.

For the side pole intrusion test, considered one of the most difficult to pass, the Model S was the only car in the “good” category 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 vs. 7.8 percent for the Volvo. Tesla says it achieved this 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 load to the rest of the vehicle.

The Model S was also substantially better in rollover risk. During testing, Tesla proudly notes that the S refused to turn over via the normal methods. Unspecified special means were needed to make the car roll. Helping the car remain in place was the S’s large battery pack under the floor pan, providing a very low center of gravity.

Most incredible is the crush resistance of the S: it broke the testing machine when crush strength went above 4 g’s.  Tesla again crows that this means at least four additional fully loaded Model S vehicles could be placed on top of an owner’s car without the roof caving in. This is achieved primarily through a center (B) pillar reinforcement attached via aerospace grade bolts.

After verifying through internal testing that the Model S would achieve a NHTSA 5-star rating, Tesla then analyzed the Model S to determine the weakest points in the car and retested at those locations until the car achieved 5 stars no matter how the test equipment was configured.

The Model S lithium-ion battery did not catch fire at any time before, during or after the NHTSA testing, nor has any production Tesla lithium-ion battery has ever caught fire in the Model S or Roadster, despite several high speed impacts. While acknowledging this is an unlikely long-term outcome, Tesla is unaware of any Model S or Roadster occupant fatalities in any car ever.

The graphic below shows the statistical Relative Risk Score (RSS) of Model S compared with all other vehicles tested against the exceptionally difficult NHTSA 2011 standards. In 2011, the standards were revised upward to make it more difficult to achieve a high safety rating.

Model S Five Star Safety Rating Chart

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