Tesla Model S scores highest marks ever seen in U.S. crash testing

As much as electric car builders hail their vehicles as the future of transportation, one question they couldn't answer fully was just how well their vehicles would withstand a crash. Automakers have spent decades finessing their chassis; what happened when an engine-less vehicle went head-on into a barrier wasn't clear, and as the post crash-test smoldering of a Chevy Volt demonstrated, the batteries posed new challenges.

Leave it to Tesla to provide the first hard evidence — with data from U.S. government tests showing the Model S sedan may be the most crash-proof passenger vehicle on the road today.

Normally, Tesla's garnering of five stars on the National Highway Traffic Safety Administration's crash tests wouldn't be a headline; most new cars and trucks get at least five stars in frontal crash protection and four stars in side impact. But the Model S did better than that; it got five stars in all tests; front, side impact, pole and rollover prevention. Plus, the scores of its frontal, side and rollover test combined were higher than any car ever crashed by NHTSA — and according to Tesla, at one point the testers nearly broke their equipment trying to damage the Model S.

For its front crash tests, NHTSA runs vehicles into a wall at 35 mph. Most cars use a combination of crumple zones — often pieces of their steel frames that look like accordion bellows — air bags and engine mounts that send the motor underneath the car to protect passengers. Since the Model S has no engine up front, it has more space for crumple zones in its aluminum chassis. In the side impact tests, which NHTSA crashes both a moveable barrier and a pole into the vehicle, Tesla says it reinforced the side rails with special aluminum slices that either stop the car or shear off a pole.

During debates between the auto industry and safety advocates last decade, automakers resisted attempts to make roofs that withstood up to three times the vehicle's weight as a protection in rollover accidents; NHTSA finally set a rule requiring that standard which will phase in through 2017, and even then still allow some crush space. The Model S withstood up to four times its weight with no crush, and the machine testing it at an independent contractor failed before it could apply more force. And because of its low-slung battery pack, the Model S carries far more of its weight closer to the ground, meaning it's harder to get shiny-side down in the first place.

As for the batteries: Tesla says the pack had no issues before, during or after the crash.

While safety used to be a strong selling point for automakers, tech advancements had made it less of a competitive advantage; even independent testers like the Insurance Institute for Highway Safety have to toughen their crash procedures every several years. Tesla's plan to sell about 20,000 Model S sedans in North America this year was running slightly ahead of schedule before the crash data came to light, but having the safest car on the road will make a few more potential buyers comfortable behind the wheel.