Tesla Motors is facing scrutiny after three of its Model S vehicles caught fire after collisions that compromised the batteries. “After garnering high praise for its styling, performance and eco-friendly electric power, the Model S will be the subject of scrutiny by the National Highway Traffic Safety Administration,” reports the New York Times. “Tesla’s chief executive, Elon Musk, said the company welcomed the inquiry.”
No one was injured in the Tesla incidents, but Tesla's stock price had fallen sharply from its high before the incidents.
Musk had quickly defended the safety of the Model S after the first incident, and he recently reiterated his position: “Since the Model S went into production last year, there have been more than a quarter million gasoline car fires in the United States alone, resulting in over 400 deaths and approximately 1,200 serious injuries (extrapolating 2012 NFPA data). However, the three Model S fires, which only occurred after very high-speed collisions and caused no serious injuries or deaths, received more national headlines than all 250,000+ gasoline fires combined. The media coverage of Model S fires vs. gasoline car fires is disproportionate by several orders of magnitude, despite the latter actually being far more deadly.”
That seems about right. The National Fire Protection Association reports that 172,500 highway vehicle fires occurred in 2012. The good news is that that number is down 8% from 2011; the bad news is that there were nevertheless 300 civilian fire deaths and 800 civilian fire injuries.
Some observers have taken issue with Musk's claims that the rate at which his cars catch on fire is low compared to which gasoline-powered cars do. Kevin Bullis at MIT Technology Review asks if Musk's contention is accurate. His answer: “Not if you’re only looking at fires caused by collisions.”
Bullis continues, “Tesla has been comparing the rate its Model S catches fire (1 in 6,333 so far) with the rate with which cars in general catch fire (1 in 1,350 per year). But these figures are really comparing apples to oranges. Only four percent of vehicle fires are caused by collisions—the rest are largely the result of mechanical and electrical failures.”
That's an exceedingly odd statement to make. If you're in a serious collision (one of the Tesla incidents reportedly involved an impact with a concrete wall at 100 mph) and your car catches on fire, that's a bad thing (obviously), but if you happen to be cruising nonchalantly down a country road and your gasoline-powered car spontaneously combusts, that's all right then?
(I'm not sure what to make of this in light of the Tesla incidents, but the predominant problems so far with Li-ion batteries have not involved accidents or collisions but rather spontaneous combustion in airplanes or laptops.)
There are all sorts of ways to spin the statistics, but thus far all the ones I have seen fail to paint Tesla in a bad light compared to gasoline-powered vehicles. Even if you accept the statistics of Burris at MIT Technology Review that fires in collisions are one in 32,603 for registered vehicles vs. one in 6,333 for Model S (reasonable), that fires in collisions are somehow more significant than fires related to mechanical failure (dubious), and that three incidents involving Tesla S fires are statistically significant (they aren't), there are still problems.
A 20-year-old jalopy is undoubtedly more likely than a new car to catch on fire because of electrical or mechanical problems. It's less likely to be involved in a fiery 100-mph collision with a concrete wall.
The only meaningful comparison of fire safety for Tesla S would be with a comparable late-model high-performance gasoline-powered car. No direct comparison comes to mind right now, but you might consider this.