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Tesla Model S achieves best safety rating of any car ever tested

teslamotors.com

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Re: Tesla Model S achieves best safety rating of any car ever tested

#151

Post by abalone »

justin66 wrote: post #149
abalone wrote: post #110

This is all very good PR.... BUT. The critical safety concern with the Tesla is....... You guessed it. The high voltage system. It can kill you or a first responder with a touch. It's not just about batteries catching fire, although that's gotten a lot of press lately. A chief concern during a Tesla accident is the exposure of high voltage components. It's a big concern for first responders. Read it from the horse's…

> I hope very much the industry can improve electrical safety over time. With regard to the electrical aspects, isn't the safety record on these cars perfect or close to perfect up until this date? That means it's only going to get worse. That does not mean electrical cars are unsafe, it just means there isn't much of a record yet. My expectation is that there will over time be a small number of electricity-related a…

Wish I had your crystal ball.

With improvement, I was referring to the complexity of cutting someone out of a Tesla and all the no-cut zones that could electrocute passengers, emergency responders, even guys towing wrecks. You're right, there is no real safety record yet.

Re: Tesla Model S achieves best safety rating of any car ever tested

#153

Post by abalone »

jlgreco wrote: post #150
agumonkey wrote: post #137

Earlier quoted context omitted.

And I guess it's unrealistic to think of a special draining device to be brought on crash sites to exhaust the car battery. All in all, are electric vehicles more 'instable' energy wise when crashed, compared to petroleum based one ? or is it different flavours of similarly sh*tty situations ?

85KWh is a lot of energy. Back of the envelope calculations puts that at enough to boil around one metric ton of water from 25C.[1] If you wanted to rapidly drain a Tesla you would have to dump that energy somewhere. That might actually be plausible for firefighters to do[2], but I doubt the battery itself would withstand being drained anywhere near fast enough for an emergency situation. It would probably find some…

Also remember we're talking about an accident scenario. There's no way emergency responders would intentionally run a high voltage circuit like that where there's a risk of short circuit in a physically compromised vehicle.

They're going to be focused on containing the energy not draining it.

It is fun to do back of the envelope calcs though.. You could run 50 space heaters for an hour off that sucker. Insane.

Re: Tesla Model S achieves best safety rating of any car ever tested

#154

Post by jacquesm »

beachstartup wrote: post #21
jlgreco wrote: post #10

Earlier quoted context omitted.

I wonder what sort of a drop 4g's translates too. It seems to me that the height you can drop it before the roof caves in is the more important figure, but I guess it is probably more difficult to accurately run the test that way.

i'm guessing that in accidents, cars very rarely drop on their tops - they either roll and come to rest upside-down, or get hit when they're already turned over/sideways.

The one thing you learn about car accidents is to not make any assumptions at all about how they progress. Cars can get flipped up and land on their roofs easily, and it doesn't take much for this to happen either. It definitely is not the most common accident but it does happen and frequently enough that they test for it.

Re: Tesla Model S achieves best safety rating of any car ever tested

#155

Post by lutusp »

abalone wrote: post #151
justin66 wrote: post #149

Earlier quoted context omitted.

> I hope very much the industry can improve electrical safety over time. With regard to the electrical aspects, isn't the safety record on these cars perfect or close to perfect up until this date? That means it's only going to get worse. That does not mean electrical cars are unsafe, it just means there isn't much of a record yet. My expectation is that there will over time be a small number of electricity-related a…

Wish I had your crystal ball. With improvement, I was referring to the complexity of cutting someone out of a Tesla and all the no-cut zones that could electrocute passengers, emergency responders, even guys towing wrecks. You're right, there is no real safety record yet.

> With improvement, I was referring to the complexity of cutting someone out of a Tesla and all the no-cut zones that could electrocute passengers, emergency responders, even guys towing wrecks.

As an electrical engineer with spacecraft experience, I can say that a car like the Model S isn't likely to electrocute anyone. While extracting someone from a wreck, emergency workers use tools like the "jaws of life", strong metal pliers meant to quickly snip a car's body apart.

When a tool like this cuts into an electric car, if it should slice through a power cable, in most cases the tool would short the cable to the car's chassis, thus grounding it and tripping the safety links that are integral to the battery pack. This means the car will become inoperative, but it doesn't mean anyone will get electrocuted.

I think the above will be the outcome in the vast majority of cases. Compare this to the plight of someone sitting in a wrecked gasoline-fueled car.

Re: Tesla Model S achieves best safety rating of any car ever tested

#156

Post by rplnt »

btilly wrote: post #89
kirse wrote: post #86

I'm sorry, but as a car enthusiast who spent much of his younger years devouring every ounce of Road&Track/Car&Driver mags, the phrase "any car ever tested" is a bit over the top... I'm almost positive the McLaren F1 (a car 20 years older) fared better than the Tesla in safety testing and was capable of being driven away after the testing finished... F1 @ 30mph: http://img.photobucket.com/albums/v482/Peloton25/McLare…

The article notes that the testing standards were changed substantially in 2011, in ways that makes them much harder to pass. The McLaren F1 might still be much safer, but it did not go through the same testing procedures.

One more reason to not compare it to "any car ever tested".

Re: Tesla Model S achieves best safety rating of any car ever tested

#158

Post by lutusp »

abalone wrote: post #153
jlgreco wrote: post #150

Earlier quoted context omitted.

85KWh is a lot of energy. Back of the envelope calculations puts that at enough to boil around one metric ton of water from 25C.[1] If you wanted to rapidly drain a Tesla you would have to dump that energy somewhere. That might actually be plausible for firefighters to do[2], but I doubt the battery itself would withstand being drained anywhere near fast enough for an emergency situation. It would probably find some…

Also remember we're talking about an accident scenario. There's no way emergency responders would intentionally run a high voltage circuit like that where there's a risk of short circuit in a physically compromised vehicle. They're going to be focused on containing the energy not draining it. It is fun to do back of the envelope calcs though.. You could run 50 space heaters for an hour off that sucker. Insane.

> They're going to be focused on containing the energy not draining it.

In an emergency that involves extracting passengers from an electric car, the most likely outcome is that the battery will get shorted to the car's chassis, at which point the emergency links in the battery will open up, isolating the battery from the rest of the car and its passengers.

Re: Tesla Model S achieves best safety rating of any car ever tested

#159

Post by jacquesm »

dredmorbius wrote: post #121
stevewilber wrote: post #78

Earlier quoted context omitted.

First: SUVs don't survive crashes particularly well This is outdated information, SUVs are now far safer than cars. Death rate (per 1M vehicle years) for 4WD midsize SUV: 23. Midsize Sedan: 51 [1] [1] http://www.iihs.org/externaldata/srdata/docs/sr4605.pdf

Interesting. The change is almost totally attributable to ESC (electronic stability control), which directly addresses SUV's Achilles' heel. It's also interesting to note the variability in results -- the Audi A6 is one of the safest luxury vehicles (I suspect the Tesla S will change that), and the Honda Accord is remarkably safe for a mid-sized sedan (though the Civic doesn't do as well relative to its class). It's…

That's per million vehicle years not per million miles.

When I read your comment I realized something must be off and went to check the source data. Imagine if the average driver drives 20K miles / year it would take only 50 drivers to get to million miles. If the death rate of cars would even approach 50 deaths per million miles then everybody would stand a good chance of dying in a car accident. Clearly this is not the case.

Re: Tesla Model S achieves best safety rating of any car ever tested

#160

Post by superfest »

axylone wrote: post #84
RomP wrote: post #22

This is simply unkind to the competition (and to the poles alike): "Tesla achieved this outcome by nesting multiple deep aluminum extrusions in the side rail of the car that absorb the impact energy (a similar approach was used by the Apollo Lunar Lander) and transfer load to the rest of the vehicle. This causes the pole to be either sheared off or to stop the car before the pole hits an occupant." There's winning an…

Here's the video of the Tesla pole test: http://youtu.be/_Al3IUHt9Wc?t=32s Honda Accord for comparison: http://youtu.be/ycntFFUfGkU?t=30s

If Tesla can bring this maintain this level of vehicle safety to its lower priced vehicles (gen iii vehicles: http://insideevs.com/tesla-gen-iii-to-eliminate-price-premiu...), then their dedication to quality, and not just economics, will be even more applaudable.
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