[ricardobeat]

Running over a trailer hitch at 70mph is a major accident. A smaller, lighter car could have been thrown off the road or rolled over, in addition to having the object puncture and invade the passenger compartment possibly causing injury, and loss of control. You're right in that it would be unlikely to cause a fire, though I wouldn't really worry about that if I was dead already.

[timr]

"A smaller, lighter car could have been thrown off the road or rolled over, in addition to having the object puncture and invade the passenger compartment possibly causing injury, and loss of control."

...or maybe not. You're just speculating.

I've run over stuff at high speeds in other cars, and I"m here to tell you that they didn't flip over, puncture, or burst into flames. The most common outcome, in my experience, is that the oil pan or transmission pan gets dented, and starts to leak.

[jobu]

I ran over a metal object on the freeway that punctured the transmission which started pouring transmission fluid onto the exhaust pipe and ignited. The truck was on fire for a few minutes before I was alerted by another driver and pulled over.

Low probability events happen all the time, and I don't think we can draw any solid conclusions from these anecdotes (other than driving any vehicle is potentially dangerous).

[StavrosK]

> Low probability events happen all the time

Hah! I love how extremely counter-intuitive and completely true this sentence is at the same time.

[moocowduckquack]

Cars do burst into flames though. There are around 194,000 vehicle fires on US roads each year from around 250,000,000 registered vehicles, which gives around 1 fire for every 1,300 vehicles. There are so far 3 Tesla fires from around 16,000 Tesla cars on US roads, which gives around 1 fire for every 5,300 of them, so they are doing better than the average. 3 fires though is still far too few to consider this a particularly useful statistic.

[aeturnum]

In order to determine how well the Tesla S handled these collisions, the stats you cited are useless. We should not count fires caused by types of accidents Telsas have never been involved in. Also, no one is accusing Tesla cars of bursting into flame for no reason, so the cars that are not in accidents aren't important either.

To really understand where the Tesla ranks in safety, we would need a detailed analysis of: the accident, how non-Tesla cars handled similar accidents, how the Tesla is designed to handle such an accident.

I do agree that we have no where near enough data to draw general conclusions about the safety of the Teslas, so I think it's inappropriate to say, "they are doing better[or worse] than the average."

[rossjudson]

A detailed analysis of "the accident" is precisely how we don't find out how Tesla "ranks in safety".

Once the numbers of cars become large enough we can simply look at the outcome numbers, to determine how likely that outcome is. It doesn't matter if a car is "designed to handle such an accident". What matters is if it does handle a given kind of accident.

A Tesla car is unlikely to ever be involved in a fire at a gasoline station. We probably shouldn't give combustion vehicles a free pass there.

As more and more Tesla cars hit the road, confidence level increases in the stats that are derived. Early data is not meaningless; it can be indicative of later results.

[aptwebapps]

I agree with the rest of the post, and this part might be true of this thread: "Also, no one is accusing Tesla cars of bursting into flame for no reason, so the cars that are not in accidents aren't important either." but not necessarily among the general public.

I think this is precisely the idea they are combating. The initial news reports didn't have any details and just said there was Tesla on fire on the side of the highway.

[001sky]

Correct this a bit and you find 3 per ~100 million miles driven on public highways. that is about ~3x worse than a regular car. 100 million miles is enough data points to be meaningful, but not exhaustive. Also, given these cars are new, the state-space of defects is likely less populated tha for the average car. Historical data show age as a factor in fires, and new cars are less likely than average-age cars to catch fire.

[thecolorblue]

I was surprised that the letter did not go into these types of details. Cars (electric or not) catch on fire. There are statistics on this. The truth about the Model S's safety has not changed. Tesla seems like a more 'sticking to their guns' kind of company rather than a adjusting tactics to handle this situation.

[drabiega]

The underside of a Tesla is quite a bit more sturdy than your oil or transmission pans. A piece of debris able to do this would do something far more serious than cause a dent or leak.

[dredmorbius]

The principle difference is that the entire underside of a Tesla is vulnerable (to a first approximation), while a conventional vehicle has a few zones of particular sensitivity (fuel tank, oil pan, gas line, possibly drivetrain).

I'm fairly impressed with Tesla's record so far, but mounting a half ton (literally) of energy storage to the entire underside does raise some interesting questions.

[InclinedPlane]

Your anecdotes are not data.

Once I had a rock the size of a golf ball smack into my windshield on the highway. It hit with such force that it made a noise that almost sounded like a gunshot, it was quite startling. It didn't leave even the smallest mark on the windshield though. Another time a tiny pebble the size of a pea hit my windshield and made a very sizeable chip in it.

Anecodtes involve luck (good and bad), the purpose of statistical analysis is to gather enough data so that the luck, which should be random, is filtered out from the "signal".

[chenster]

"I've run over stuff at high speeds in other cars, and I"m here to tell you that they didn't flip over, puncture, or burst into flames...."

It really depends on what kind stuff the car runs over and how fast the car is moving, and also how well the driver is handling the situation when it happens. I've almost run over ladders and mattresses, but never trailer hitch. Maybe I'm lucky.

[spitfire]

No it isn't. I've driven over a large rock cast off from an RV going 80mph in a little (2000lbs) sportscar made in the 1960's. There was a large bump, grinding sound and damage to the underfloor (you could poke your finger through).

But in no way was it a major accident.

[URSpider94]

Please read my separate post about a very similar accident a decade ago that killed 6 children. I don't think anyone can make blanket statements about what is and isn't a serious accident.