A federal safety agency just announced an investigation into the Tesla Model S sedan, examining whether the design of the vehicle and its lithium-ion battery pack are defective and the cause of battery fires.
The high-end vehicle will be the subject of scrutiny by the National Highway Traffic Safety Administration, on whether the size, shape and chemical makeup of the car's battery makes it prone to fires when its lithium-ion cells are punctured in a collision.
Elon Musk, Tesla's chief executive, has defended the design of the Model S, but the car has caught fire on three occasions in less than two months, twice in the United States and once in Mexico.
The investigation can take months to complete, and might include crash tests well beyond the ordinary government testing done on cars before introduction.
Tesla has pledged to extend its current vehicle warranty to cover fire damage.
The Model S, which is priced at $700,000 and higher, won early accolades for its safety from regulators and independent publications like Consumer Reports.
The first fire occurred on Oct. 1 when the car struck a metal object on a highway in Washington, outside of Seattle. The second incident occurred in a high-speed crash in Mexico on Oct. 18, and the third fire occurred on Nov. 6 in Tennessee, after the Model S ran over a tow hitch in the road.
The latest accident prompted regulators to revisit their earlier statement of the car's safety.
If the car is deemed structurally unsound, the agency could recommend that Tesla add a protective covering to the battery, which would be expensive and could compromise performance.
Source: The New York Times, "After 3 Fires, Safety Agency Opens Inquiry Into Tesla Model S," November 19, 2013