Tesla not planning a Model S recall: CNBC

[sleepyhead]

Again, I would have to say check your units and how you are sampling them. In your case, you are trying to sample for cars six months ago.

The first thing is you can't just subtract the number of new cars from that number, because there are also used cars that were removed from/added to (for example putting a non-operational vehicle back on) the road during that six month period which will skew the numbers. The most accurate way to do this is to use the population size of the vehicles sampled to arrive at that 150k number (keeps numbers consistent). The reason the ICE numbers tend to be accurate is the sample is large enough and ICE cars on the road does not vary too much per year.

Second of all (and this is more important), is if you do sample from six months ago, you also have to consistently sample the number of fires from six months ago and that was 0 for the Model S, so that puts Tesla at 0 chance of fire (which is meaningless).

Put another way:
6 months ago - 0 fires per year / 12k Model S
Now - 3 fires per year / 25k Model S

If you assume same risk of fire per vehicle you would expect:
Future - 6 fires per year / 50k Model S
Future - 12 fires per year / 100k Model S (and so on)

You can't arbitrarily pick fires that happened 6 months later with a 2x larger population for Tesla and then limit the sample size to 6 months before (when 0 fires happened). The math just doesn't work that way (you can only do that for ICE because total cars on the road does not vary much per year).

Yes, there is a side point that the Model S volume and number of measured fires are too low to say there's statistical relevancy, but that's a different point.

Like I said before, I don't have time to debate this subject anymore. I know that my math is correct and I am sure of that. Maybe I didn't explain it correctly.

Elon is comparing apples to oranges when saying 5x less likely to catch fire. I am "annualizing" Teslas in order to create an apples to apples comparison, which leads to ~2.5x-3x less likely, using the same (flawed) methodology that Elon used.

I was just trying to show that Elon was misleading with the math he did. That is all.

 

[MartinAustin]

Elon is comparing apples to oranges when saying 5x less likely to catch fire.

There really isn't any simple way to put it in manageable sound bites. I think Elon's way of putting it is no less accurate than the reporting of Model S fires by press and critics - but, he is also basically right, even if the number involved isn't exactly 5.0.

The press and critics are also comparing apples to oranges. They're saying "the Tesla Model S ended up on fire. A fire is a fire is a fire. Three fires. Dangerous!" There were two unplanned fires and one that followed a massive error in driver judgement (not the fault of Tesla Motors and everyone should be disregarding).

The two unplanned fires started so slowly that both drivers were able to pull over, get belongings and get out safely. There is simply no data yet existing to suggest you can be surprised, overwhelmed, taken aback etc. by a fire in your Tesla. We see that all the time with ICE cars though.

They're not the same thing... apples and oranges.

When Dick Van Dyke's Jaguar burned, he was also able to get out safely but the car burned afterwards.
http://www.youtube.com/watch?v=kPiG3gFRjHE

Tata Motors' stock didn't drop as a result, the press did not infer that perhaps there could be a specific hazard with Jaguars that causes them to catch fire.

 

[stopcrazypp]

Like I said before, I don't have time to debate this subject anymore. I know that my math is correct and I am sure of that. Maybe I didn't explain it correctly.

Okay, we can only agree to disagree if that's your perspective. But the way Elon is calculating it makes more sense to me.

 

[Johan]

Like I said during Elon's interview on the short term thread: however you're calculating it, using statistics here, no matter how favorable, is just so plain wrong from a PR perspective. You set your self up for failure. More over IMO Elon let's his slight Aspberger sydrome shone through here : dollars, kWh, miles of range etc. etc. now those are things that are OK to speak about analytically, mathematically and statistically. Fires/safety/risk of death or injury not so much (from a PR perspective).

The only correct answer is: We still believe we have the safest car on the road but we are looking in to these very uncommon incidents with all our available resources and if there is any way to further improve the Model S when it comes to the safety of the occupants you can be rest assured that we will make those improvements.

 

[Raffy.Roma]

The only correct answer is: We still believe we have the safest car on the road but we are looking in to these very uncommon incidents with all our available resources and if there is any way to further improve the Model S when it comes to the safety of the occupants you can be rest assured that we will make those improvements.

You couldn't say it better! IMO starting from the Model S that is available now some changes could be done to improve the performances and in the same time the safety and reliability of the Model S.

 

[SwedishAdvocate]

Like I said during Elon's interview on the short term thread: however you're calculating it, using statistics here, no matter how favorable, is just so plain wrong from a PR perspective. You set your self up for failure. /.../ dollars, kWh, miles of range etc. etc. now those are things that are OK to speak about analytically, mathematically and statistically. Fires/safety/risk of death or injury not so much (from a PR perspective). /...

Why?

.../ The only correct answer is: We still believe we have the safest car on the road but we are looking in to these very uncommon incidents with all our available resources and if there is any way to further improve the Model S when it comes to the safety of the occupants you can be rest assured that we will make those improvements.

To me, that sounds like admitting that there could be something wrong with the car.

But could there be something wrong with the car?

Aren’t we all aware that there is no such thing as a figuratively speaking ‘bullet proof car’?

Now we know that a Tesla Model S can catch on fire if it encounters something that exerts a pointed force of ~25 tons directly at the bottom of the battery pack. Sure. That is not ideal by any means, but how should Tesla have played it. Should they have chosen another design of the battery pack? That would have brought other negatives.

Unfortunately it seems that designing an electric car that is absolutely ‘bullet proof’, as in that it would never ever risk catching on fire, seems to be physically impossible…

 

[Raffy.Roma]

@SwedishAdvocate

There is nothing wrong to improve a completely new car adopting also a new technology like the Model S. According to the quality principle quality has always to be improved.

 

[SwedishAdvocate]

@SwedishAdvocate

There is nothing wrong to improve a completely new car adopting also a new technology like the Model S. According to the quality principle quality has always to be improved.

So if a Model S encounters something that exerts a pointed force of ~25 tons directly at the bottom of the battery pack, how much less likely to catch on fire a couple of minutes after such an event – percentage wise – do you think the car can get?

 

[Johan]

Why?

To me, that sounds like admitting that there could be something wrong with the car.

But could there be something wrong with the car?

Aren’t we all aware that there is no such thing as a figuratively speaking ‘bullet proof car’?

Now we know that a Tesla Model S can catch on fire if it encounters something that exerts a pointed force of ~25 tons directly at the bottom of the battery pack. Sure. That is not ideal by any means, but how should Tesla have played it. Should they have chosen another design of the battery pack? That would have brought other negatives.

Unfortunately it seems that designing an electric car that is absolutely ‘bullet proof’, as in that it would never ever risk catching on fire, seems to be physically impossible…

Why? Since when you start throwing numbers like that around they better be so solid that there is no way to question them. Just look at this thread and see how many very legitimate types of critisism you can come up with regarding these "statistics". With so few cars on the road Tesla are very vulnerable right now taking this "the numbers prove we are safer" route. What if two or three more idiots drink, drive and crash like the guy in Mexico? It has to go in the "fire stats" right? My point is going this routes puts Tesla out of control of the issue and instead vulnerable to chance, drivers' errors, freak incidents, shenanigans by competitors etc. By taking ownership of the fires they would be able to control the portrayal and perception a lot more and move it in the direction they choose. There is a way to take on responsibility and show responsiveness and leadwrship without admitting failure/wrong doing/bad design or what ever. Organizations that master PR do this all the time, good politicians do it etc.

Disclaimer: I'm not worried about the saftey, to me this is a small issue. But public perception is everything right now.

 

[SwedishAdvocate]

Off the top of your head, can you think of one such example that could be used as a comparison?

 

[PeterJA]

... In the northwest, in stormy winters, I know more than a few people that have come around a corner to find a pretty major branch blown off the tree and laying across the road/highway (lot of 2 lane highways winding through forested areas) or non-trivial rocks that fell onto the road from the hillside the road was carved into.

I punctured my gas tank driving on a rural road in Arizona. I was driving too fast (maybe 25 mph) on a dirt road with many sharp rocks of all sizes. I heard a thump, stopped, and saw gas gurgling out underneath. I don't think I scraped an anchored rock. I think a small sharp rock was flung up by my (powered) front tire. Either way, I wish I had been in a Model S.

A flung or scraped rock would not have exerted anywhere near the 25 tons of force that pierced the armor-plated battery in the first Tesla fire incident. In a Model S, I would not fear fallen branches or rocks or mufflers or beer cans or any other objects normally meant by the term road debris. The objects that pierced Tesla's armor plate were not normal road debris. They were a "curved section" of a fender and a "three-pronged trailer hitch that was sticking up with the ball up in the air." I would call these objects machinery. I would call the incidents that caused the fires collisions.

In a Model S, I would not fear even these objects, because I'd know that everyone in the car is protected by TWO armor plates (the bottom and top of the battery pack), and the car will warn me and give me time to get out safely if necessary, not "burst into flames" as some media have reported.

Maybe we could help the public perception of the fire incidents become more accurate if we stopped saying "ran over road debris" and started saying "collided with machinery."

 

[anticitizen13.7]

Having considered this situation for a few days, I have come to the conclusion that no automobile can be made completely accident-proof. The Model S is still an incredibly safe car: no other passenger automobile provides better crash protection. When the battery pack did catch on fire in the first incident, the pack design worked. It vented the flames away from the cabin, and the driver was able to pull over and exit the vehicle without injury.

We can obsess over whether the Model S battery could be made safer, but the truth is that nothing is 100% guaranteed safe. Not even the innocuous Apple iPad Air, one of which exploded in the UK a few days ago.

I am sure that Tesla will continue to improve what is already a very safe design.

 

[Krugerrand]

Yes. Thank you. Should avoid sarcasm.

Nope, don't avoid it. Maybe just a little emoticom after the sarcasm so that it's not missed? Though, perhaps if I'd read it at different time or another day I'd have caught it.

 

[andrewt3000]

Consider this thought experiment... what if a car company decided to make a fuel tank that mimicked the dimensions of the Model S battery pack. Even with 1/4 inch armor, it would be a questionable design. The long term solution, I believe, is likely to be battery packs that are higher and near the rear of the car, like current gas tank designs.

In the short term, I don't know. Maybe they can increase the armor, raise the car suspension at high speeds, or add some sort of cow catcher. Another cool idea would be a sensor that scans for debris and raises the car... Elon Musk is a resilient, adaptive entrepreneur and I think it's likely Tesla will prevail.

 

[anticitizen13.7]

Consider this thought experiment... what if a car company decided to make a fuel tank that mimicked the dimensions of the Model S battery pack. Even with 1/4 inch armor, it would be a questionable design. The long term solution, I believe, is likely to be battery packs that are higher and near the rear of the car, like current gas tank designs.

A fuel tank could not easily be made into a shape like the Model S battery pack. First, there is the issue of the fuel pump. The pump needs to be submerged in gasoline in order to stay cool. A very shallow but wide tank would make this difficult. There is also the problem of routing the exhaust pipe.

A battery could certainly be made with the shape and placement of a fuel tank. However, the trade off is that the pack no longer serves as a structural reinforcement for side impacts. Also, concentrating a heavy battery over the rear axle will alter the weight distribution of the vehicle.

I think we need to wait a few months to a year to see if the floor mounted battery becomes a more widespread liability.

 

[PeterJA]

Consider this thought experiment... what if a car company decided to make a fuel tank that mimicked the dimensions of the Model S battery pack. Even with 1/4 inch armor, it would be a questionable design.

Your thought experiment is not like Tesla's design. A gas tank could be ignited instantly by a trailer hitch sticking into it and throwing sparks from dragging on the road. Tesla's battery took several minutes to ignite. Also, a gas tank is not divided by firewalls into 13 compartments like Tesla's battery pack.

The long term solution, I believe, is likely to be battery packs that are higher and near the rear of the car, like current gas tank designs.

I disagree. I prefer having that armor-plated battery pack protecting me and all my passengers from collisions with low-lying machinery.

 

[azure1979]

Perhaps Tesla already has improved undercarriage protection of new cars. here is the patent about battery pack protection.

http://www.patentlens.net/patentlens/patents.html?patnums=US_8286743#tab_2

 

[mershaw2001]

This was filed in 2011, so it could be the current standard that they are using now.

 

[FredTMC]

Perhaps Tesla already has improved undercarriage protection of new cars. here is the patent about battery pack protection.

http://www.patentlens.net/patentlens/patents.html?patnums=US_8286743#tab_2

If the battery can be actively fire suppressed via foam, halon, water etc then I still like this idea a lot. Not sure of the science though but I certainly think this is possible at a reasonable cost. Yes, I know the battery already has some suppression tactics but I'm talking about an active release of fire suppression liquid/gas/foam (flooding of the battery compartment) in the event of a thermal run away or endothermic chemicals. Assuming this is possible at a reasonable cost this would drastically reduce cars on fire by the side of the road. Eliminates the media drama effect of YouTube videos of cars of fire. Final comment: I don't think any recall is required on existing cars, since occupants have plenty of time to exit in these 2 highway incidents. This is simply any improvement that could be done to future packs.

 

[mrdoubleb]

A recall would only make sense if such fires were spontanious or would happen for a significant number of crashes. Thank god, neither is the case. We have seen plenty totalled Teslas on these forums (there is a thread but i am too lazy to look it up :tongue: ), but it seems you need a significant incident and freaky situations (an object neither small enough to pass under, nor big enough to be kicked aside by the car) for this to happen.