Tesla not planning a Model S recall: CNBC

[sleepyhead]

My math is a little rusty, but wouldn't this depend on whether the 1/1300 stat is per car per year vs. at any given moment 1/1300 ICE cars will catch on fire?

I was assuming it is per year, but if it is over the life of the car then the math comes out a lot worse for Tesla. You would then have to adjust for the percentage of useful life instead of annualizing.

Either way I don't like how he presented the math.

 

[Norbert]

My math is a little rusty, but wouldn't this depend on whether the 1/1300 stat is per car per year vs. at any given moment 1/1300 ICE cars will catch on fire?

It's most likely from annual statistics about fires/year in the US, and existing cars in the US. (The 2nd fire (of 3) was in Mexico, so you need to make sure to use world-wide numbers consistently, or US numbers consistently, for Tesla.)

 

[Chickenlittle]

I was assuming it is per year, but if it is over the life of the car then the math comes out a lot worse for Tesla. You would then have to adjust for the percentage of useful life instead of annualizing.

Either way I don't like how he presented the math.

It upsets me to know end to hear your displeasure

 

[mershaw2001]

It upsets me to know end to hear your displeasure

The math, as originally presented for the 5x safer statistic, was based on miles driven, if I recall correctly. The math you present above (that I assume is a quote from him in the interview) is different from the math that was originally used to derive the 5x safer statistic.

The inherent probability of the car catching fire hasn't changed, we're just sampling a larger population of car-miles and because we're sampling a population that is boundary constrained, the 2 vs 3 fires would not make a large difference in calculating the probability (it doesn't increase the probability by 50%).

 

[stopcrazypp]

I was assuming it is per year, but if it is over the life of the car then the math comes out a lot worse for Tesla. You would then have to adjust for the percentage of useful life instead of annualizing.

Either way I don't like how he presented the math.

The number appears to be fires per year per car:
150k fires/year / 200 million cars
versus
3 fires/year / 25k Model S

There is so far no statistics presented that useful life changes that number dramatically (or even at all). There was some attempt to simulate this by dividing by the average age of vehicles on the road (~11 years), but that assumes a car of the Model S's age (~1 year) is 11x less likely to catch on fire than one of the average age (risk goes down linearly with age) and there is absolutely no evidence of this.

 

[NoMoGas]

Hello Shark... meet Thread dissecting a math equation ... Thread, meet the Shark.. Now JUMP!

:biggrin:

 

[sleepyhead]

The number appears to be fires per year per car:
150k fires/year / 200 million cars
versus
3 fires/year / 25k Model S

There is so far no statistics presented that useful life changes that number dramatically (or even at all). There was some attempt to simulate this by dividing by the average age of vehicles on the road (~11 years), but that assumes a car of the Model S's age (~1 year) is 11x less likely to catch on fire than one of the average age (risk goes down linearly with age) and there is absolutely no evidence of this.

200m cars of which a vast majority are used and a full year on the road. So if you annualize all of the new cars less than 1 year old you might get 180m cars annualized.

180m/150k fires = 1 fire per 1,200 cars

Model S = 25,000 cars but when annualized you get closer to 10,000 cars since more than half the cars are less than 6 months on the road.

10k/3 fires = 1 fire per 3,300 cars

3,300/1,200 = 2.75 times less likely to start on fire and not 5 times.

The math that Elon presents is misleading and that is what bothers me. After the first fire he correctly used miles driven to show that it is 5 times less likely. But now that the math doesn't work in his favor his is incorrectly doing math to stay at 5x, and this is incorrect.

 

[RobStark]

One of the fires occurred in Mexico.

It is not correct to lump Mexican+American Tesla statistics or Global Tesla statistics vs American Gas powered automobile statistics.

I don't know what the rate of fire is for Mexican gas powered cars but given the state of highways in Mexico vs USA my guess would be that they are higher in Mexico.

 

[ckessel]

One of the fires occurred in Mexico.

It is not correct to lump Mexican+American Tesla statistics or Global Tesla statistics vs American Gas powered automobile statistics.

I don't know what the rate of fire is for Mexican gas powered cars but given the state of highways in Mexico vs USA my guess would be that they are higher in Mexico.

If Tesla is counting that car in its "miles driven" then it counts. Tesla can't count its miles, but not its fire. It has to be both or neither.

 

[azure1979]

The most important point is that the model s has weakness from road debris as compared with other cars, because the battery size of undercarriage is larger than other EV's or ICE fuel tank. we know that, but no one talk about the issue. Eventually undercarriage protection ability of modes s must be improved from road debris.

 

[deonb]

Why is it a must for any change? I just want to know the cabin won't be penetrated by a fire and that the fire is safely being directed away, as it is currently designed, and I'll be happy.

The cheapest way for Tesla to solve this is to put Elon in a Model S and then simulate the Tennessee collision to set the car on fire, and then show that the driver is perfectly safe during the event (which they should be based on the Tennessee guys' email).

 

[stopcrazypp]

200m cars of which a vast majority are used and a full year on the road. So if you annualize all of the new cars less than 1 year old you might get 180m cars annualized.

180m/150k fires = 1 fire per 1,200 cars

Model S = 25,000 cars but when annualized you get closer to 10,000 cars since more than half the cars are less than 6 months on the road.

10k/3 fires = 1 fire per 3,300 cars

3,300/1,200 = 2.75 times less likely to start on fire and not 5 times.

I don't get where you are getting this "annualizing". You have to check the effect on units for the final number. The number of cars used in both cases is the number on the road and the fires are also sampled from this population.

If you are trying to limit the sample to only 1 year old or newer cars, then I bet there is way less than 180m (only 14.5 million new cars were sold last year in the US). Then you also have to sample only the fires that happened to 1 year old or newer vehicles (this is the number no one is able to find).

I also would like to say the 200m and 150k I'm using is just my guess for the base numbers that arrived at 1/1300. It could also be 250m and 190k (or other combinations) depending on what statistics you are using.

 

[dm33]

This is very disconcerting.

Nissan LEAFs and Chevy Volts have driven a combined 500 million miles, with ZERO fires (other than the Volt after sitting weeks after a crash test).

Elon cites very dangerous and misleading statistics. The vast majority of fires in gasoline cars are not from a collision. They're predominantly from very old cars with dry rotting cracking fuel lines that spew gasoline onto hot exhaust. A smaller percentage of car fires occur as a result of an accident. I had seen a chart with this statistic and need to find it again.

Therefore, if you look at the percentage of fires in gasoline cars resulting from accidents, I believe the rate is likely lower than the rate of fires so far in Teslas. Especially when you consider the age of vehicles on the road, the number of miles driven, etc.

Propping a stock up to these levels requires excellent execution and an excellent management team. Even if they make a mistake, you're banking on having really smart people who'll figure out the best course of action. To claim there is no problem, and nothing needs to be done does not represent the excellent management that is expected of this stock valuation.

Tesla should have said they're looking into it and will release a statement at a later date. They should have come up with some improvement, no matter how minor to remediate the situation. Could be as easy as changing the default height on the suspension to be higher and let the user lower it with a disclaimer.

Ignoring the problem is a recipe for disaster. He makes a big deal to claim no one has been injured or died. What about the next time when someone is in a collision, knocked unconscious and the car goes on fire. What will his excuse be then? More creative statistics about death rates vs. gas cars?

I'm hoping its not true and they continue to investigate.

Running over a little hitch should not cause a car to go up in flames. It will happen again if thats all it takes. Eventually, someone is going to get hurt. Eventually, Tesla will have to do something about it. Ignoring a problem only makes it worse.

 

[Mile Erlic]

From the National Fire Protection Association:

"Collisions and overturns were factors in only 4% of highway vehicle fires, but these incidents accounted for three of every five (60%) automobile fire deaths."

Also about 152,000 car fires per year.

 

[sleepyhead]

I don't get where you are getting this "annualizing". You have to check the effect on units for the final number. The number of cars used in both cases is the number on the road and the fires are also sampled from this population.

If you are trying to limit the sample to only 1 year old or newer cars, then I bet there is way less than 180m (only 14.5 million new cars were sold last year in the US). Then you also have to sample only the fires that happened to 1 year old or newer vehicles (this is the number no one is able to find).

I also would like to say the 200m and 150k I'm using is just my guess for the base numbers that arrived at 1/1300. It could also be 250m and 190k (or other combinations) depending on what statistics you are using.

You have to "annualize" the numbers, because even though there is about 25k Teslas on the road today, there was only 12k Teslas on the road 6 months ago. There is 200m ICE cars on the road today and there was probably 198m ICE cars on the road six months ago (which I now realized that I should have used 198m instead of annualized 180m, so it will make Tesla's claim look even worse but that is not important).

If you put 975,000 Teslas on the road tomorrow and none of them catch fire then Elon (using his voodoo math) could say that we have 1m Teslas and only 3 caught fire, which means 1 in 330,000 Teslas catch fire vs. 1 in 1,300 ICE cars which means Teslas are 280 times less likely to catch on fire.

Obviously I exaggerated this a lot to prove a point: 1 year ago there were only a couple thousand Teslas and that number is growing exponentially by the day. And that is why you have to annualize. Whereas there is about the same amount of ICE cars today as a year ago, so the annualized number is very close to today's number of cars on the road. In Tesla's case, since the number of cars is growing exponentially, the annualized number is going to be less than 50% of that 25k Teslas on the road.

I don't have time to debate this topic anymore, but I am 100% positive that I am correct in the way I am doing math and Elon is misleading with these numbers (unless he adjusted that 1,300 number to account for an "annualized" number of Teslas on the road, which is highly unlikely).

"Statistics can be made to prove anything - even the truth." ~Author Unknown

 

[Jhall118]

You can't compare two groups with such large sample differences. It's meaningless. What's the number of cars that hit road debris with 25 tons of force? What percent of those cars get totaled? There just isn't enough data to provide meaningful insight yet. Unfortunately, if Elon said that, the only people that wouldn't flip **** is those with education in statistics.

If you want to keep playing number games, consider the following:

0 deaths / number of model S accidents is infinitely safer than the number of deaths occurring in combustion engine cars.

 

[sleepyhead]

This is very disconcerting.

Nissan LEAFs and Chevy Volts have driven a combined 500 million miles, with ZERO fires (other than the Volt after sitting weeks after a crash test).

Elon cites very dangerous and misleading statistics. The vast majority of fires in gasoline cars are not from a collision. They're predominantly from very old cars with dry rotting cracking fuel lines that spew gasoline onto hot exhaust. A smaller percentage of car fires occur as a result of an accident. I had seen a chart with this statistic and need to find it again.

Therefore, if you look at the percentage of fires in gasoline cars resulting from accidents, I believe the rate is likely lower than the rate of fires so far in Teslas. Especially when you consider the age of vehicles on the road, the number of miles driven, etc.

Propping a stock up to these levels requires excellent execution and an excellent management team. Even if they make a mistake, you're banking on having really smart people who'll figure out the best course of action. To claim there is no problem, and nothing needs to be done does not represent the excellent management that is expected of this stock valuation.

Tesla should have said they're looking into it and will release a statement at a later date. They should have come up with some improvement, no matter how minor to remediate the situation. Could be as easy as changing the default height on the suspension to be higher and let the user lower it with a disclaimer.

Ignoring the problem is a recipe for disaster. He makes a big deal to claim no one has been injured or died. What about the next time when someone is in a collision, knocked unconscious and the car goes on fire. What will his excuse be then? More creative statistics about death rates vs. gas cars?

I'm hoping its not true and they continue to investigate.

Running over a little hitch should not cause a car to go up in flames. It will happen again if thats all it takes. Eventually, someone is going to get hurt. Eventually, Tesla will have to do something about it. Ignoring a problem only makes it worse.

I completely agree with this post. If there is another fire soon, then the stock is going to tank to $80 or lower.

They should look into it and at least see if there is an easy fix, even if it costs a couple hundred dollars per car.

 

[birdsaresmarter]

The most important point is that the model s has weakness from road debris as compared with other cars, because the battery size of undercarriage is larger than other EV's or ICE fuel tank. we know that, but no one talk about the issue. Eventually undercarriage protection ability of modes s must be improved from road debris.

Actually somebody else DID bring up that question (kind of wondering) amidst the flood of posts and numerous threads. It had crossed my mind as well, however, I do not think we can simply assume that the entire surface area of the battery pack is really as likely to endure the strikes from debris of the right physical characteristics to cause this kind of a problem.

I am sure EVERYBODY will correct me if I am wrong, as I am speaking intuitively as opposed to scientifically. However, I think, for example, deflected debris approaching from the side of the vehicle is less likely to get under the car without similarly being deflected by other structure of the car, not being subject to the same "head on" collision force to ram it underneath and then upward.

I just don't think one can assume that the surface area of the pack alone is going to be the determining factor.

I'm going to go put on my flack jacket now.

 

[sleepyhead]

You can't compare two groups with such large sample differences. It's meaningless. What's the number of cars that hit road debris with 25 tons of force? What percent of those cars get totaled? There just isn't enough data to provide meaningful insight yet. Unfortunately, if Elon said that, the only people that wouldn't flip **** is those with education in statistics.

If you want to keep playing number games, consider the following:

0 deaths / number of model S accidents is infinitely safer than the number of deaths occurring in combustion engine cars.

I am not playing games. I am pointing out that Elon's "number games" are extremely flawed; that is it!

Too many emotional TSLA investors on this board. I am trying to speak the truth and a vast group of people on TMC get upset because they don't like hearing anything negative on Tesla.

I want to see the company succeed as much as anyone else, but I am not going to avoid criticizing Tesla when it is warranted.

Elon is misleading the public with statistics and that is not cool. Other than that, I agree that the sample size is too small.

It still doesn't change the fact that Elon did the math wrong.

 

[ggies07]

The interviewer had WAY too much energy. Elon seemed bored with the questions, looking down at his fingers while moving them across the table and putting his fist on his temple while talking. Almost like his was made to be there......