Tesla Model S achieves best safety rating of any car ever tested | Hacker News Reader

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

teslamotors.com

814 pointsturing301 comments

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 mouth, the Tesla Emergency Response Guide. Page 16 highlights the "no cut" zones of the car. It's practically the entire length of the car.

http://www.teslamotors.com/sites/default/files/downloads/201...

There was a video they put out as well that details the steps first responders need to take to cut someone out of a car. It's HELLA COMPLICATED and in very close proximity to dangerous high voltage components.

And yes, gas cars can explode, etc. I don't mean this as fuel for the gas vs. electric debate (no pun intended). I hope very much the industry can improve electrical safety over time. All I'm saying is, never trust Elon Musk PR to tell you the whole picture.

> All I'm saying is, never trust Elon Musk PR to tell you the whole picture.

Never trust anyone's PR to give you the whole picture!

Though as a counterpoint, I've seen cars with the roof cut off to extract people, but never the side doors or the floor cut open. I don't think they'd cut the floor since it's quite thick and has all sorts of wires and pipes anyway.

Firefighter here...

The major thing that concerns me about the Model S is the placement of the DC-DC converter in the front right wheel well. There's a common maneuver called a 'dash lift' where you make a couple relief cuts and then lift the dash using a hydraulic ram. Properly place, those cuts are dangerously close to that high voltage system.

Explanation of relief cut placement: http://advancedextrication.com/2011/12/closer-dash-lift-part...

EDIT: The video abalone posted has a great walk-through on rolling the dash of a Model S. http://www.youtube.com/watch?feature=player_detailpage&v=ntK...

Another issue is the seat belt pretensioner, which would complicated a 'side blitz' door removal (where both doors are removed as a unit), but that's a pretty standard place for the pretensioner, so it's something we're used to working around.

Looks challenging. How does that compare with a Prius?

A Prius is a lot simpler. All the electric components are well away from all the 'usual' cut locations.

Obviously all the normal concerns apply (air bags, pretentioners, etc), but from an extrication perspective, they're pretty straightforward.

The one issue common to all EVs (hybrid or plugin) is that the can silently deliver power to the wheels. With a 'normal' car, you can hear the engine running. With an EV, it can be harder to tell if it's on or not.

One of the first things we do it secure the keys, but with keyless ignition, the key may be trapped in the drivers pocket. That means the big round 'On' button just needs to be bumped by someone for the car to power up. That's why it's critical that we're able to disable the electrical systems of the car, to prevent it from starting up unexpectedly.

You've never seen doors cut off? You must not have seen much then.. happens all the time. Google jaws of life.

BTW here is the Tesla first responder training video that shows how to cut off a door(!) and move the dash without electrocuting yourself. http://www.youtube.com/watch?v=ntK3rvVl2Qw

It's a pretty cool video, I expect most people on this thread would enjoy watching it. I sure did.. although I'm not sure I'd want to be stuck bleeding in a Tesla while they figure it out.

Also a little concerned about a short happening during an accident and electrifying passengers.. would like to know more about the risks there.

> 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 accidents involving first responders and passengers and that they will be enough to fuel concern trolls until the end of time. That the electrical problems will be so enormous that they dwarf the massive safety gains from better passenger protection of the sort NHTSA is interested in (and frankly, anyone who is about to get hit by an oncoming SUV is interested in) seems awfully counterintuitive.

Aren't those the same concerns people had when gasoline cars were introduced? It was considered to be too dangerous to use.

Fast forward to today, cars are not exploding. Battery safety issues will be dealt with.

Considering the fact that Tesla batteries are made for lots of really tiny cells, I can't imagine it is impossible to disconnect them from each other in the case of a crash.

I don't know about individually disconnecting each cell, but there is a loop that emergency responders are supposed to manually cut to disconnect the battery. However there are still components that retain power and remain hazardous such as the converter and capacitors. Firefighters need to take great care to cut around them. Plus there's the possibility of the battery compartment being compromised in an accident as well. Tesla's training video covers all this.

Nobody's arguing that Teslas are unsafe, just that the "safest car" claim sidesteps the electrical safety issue. You can't really argue that everything's fine because nothing bad has happened yet, because there are so few Teslas on the road. And it should be noted, a lot of people were hurt along the path to making gasoline cars as safe as they are today. Look at Ralph Nader's work on automobile safety for example.

I actually believe progress demands that we work through electrical car safety. But what irks me is it's just a little premature to be trumpeting "SAFEST CAR EVAR" when you've got a novel set of serious safety issues that the test suite doesn't even try to target.

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.

Hi there. Go ahead and watch this video from Tesla about how to cut someone out of a Tesla. The very first step is to cut the circuit like you say, but there are a few things you overlooked.

Much of the video is concerned with instructing responders how to cut around components that may remain electrified such as the converter and capacitors which, in Tesla's own words, present a "serious hazard of shock" because "they can release up to 400 volts in just an instant."

http://www.youtube.com/watch?v=ntK3rvVl2Qw

Nitpicking, I know, but releasing 400 volts means nothing. Current kills, tension does not. It all hinges on the internal resistance of the power source.

Voltage means A LOT. A regular 12V car battery is a perfect proof: it has enough current to kill you, but at only 12V it doesn't overcome your body's resistance much under most circumstances.

400V can overcome your body's resistance no problem. And obviously an EV has a crap ton of amperage as well.

That and time. You could get hit with high volts and current, but still be fine if the exposure is short. I have had a few 240v mains shocks on high current fuses, but they were all pretty quick and I had nothing but very slight burns and sore muscles for about ten minutes.

However, there is definitely a risk here, albeit what appears to be a manageable one. Perhaps there could be some use in building volt meters that glow into gloves for emergency responders to help mitigate some of the risk.

Perhaps it would be even better to say, "power transmission kills."

Well, also the resistance of the load.

Do other car manufactures provide such videos?

I know a paramedic in rural Australia. They get taken to local car dealers to get safety training with electric cars.

As I understand it it's done on a per-model basis, but that wont really work as an increasing number of electric car models end up on the roads. I'm not sure if this is done all over the state/country, or if it's the one local dealer being friendly with the local emergency services.

Would an independent accelorometer in the battery assembly shut of the power when the car is involved in a collision?

It wouldn't make sense for it to be dependent on a link from the airbag sensors, it would have to be local to the power plant.

Would the tools used not be developed?

I would've assumed the production of specialised tools for electric cars would be a priority once they become popular.

Presumably, avoiding electrocution of the passenger being extracted is also a goal.

I don't understand your response, is this not what the specialised tools would be primarily designed for?

What sort of tools are you envisioning?

maybe insulated ones

Insulating the tools isn't really the issue. There's already a fair amount of insulation between me (the tool operator) and the business end of the tool.

The problem is, we're cutting through and crushing various bits of the car that weren't really designed to be indiscriminately cut into (which is why training is so important).

Both rescuers and victims have been seriously injured and killed when extrication activities turned potential energy stored in the car into kinetic energy. Air bag deployment systems, seat belt pretensioners, even the little hydraulic tubes that hold your trunk open and be extremely dangerous if their energy is released in an uncontrolled way.

So you can understand why we're a little leery of 85 kWh of potential energy sitting under the car...

Here's an example of airbags being deployed when the SRS controller was crushed with a hydraulic spreading tool.

https://www.youtube.com/watch?v=yDSksTztHJk

Two firefighters were injured in that incident (one of them seriously).

Does anyone know what the actual voltages are?

Just because it is high relative to the usual 12V of cars does not mean it is terrifically fatal.

An anecdote to give you a picture of things: Electric arc welders operate at around 60V with a very large amount of current. However the electricity is not particularly the dangerous thing about them, it is the 9000F arc you are making and the molten steel. So to demonstrate that we shouldn't freak out about the electric danger and worry more about the heat, my instructor had someone touch the business end with one hand and the ground electrode with the other. Bit of a tingle but certainly didn't stop their heart or anything. Welders are kept at low voltage for this reason.

I assume that it must be somewhat dangerous because of the responder guides warning, but I would want to know the actual voltage before drawing conclusions. If the voltage is 112 or less (or even 220 or less), it should be possible to be pretty safe with some fairly manageable precautions.

These are very high voltages. The Tesla is 375 volts and the Prius is 275 volts.

Technically, that puts it well into the 'low-voltage' classification; generally, 1000 V is the threshold for 'high-voltage'.

> generally, 1000 V is the threshold for 'high-voltage'

DCV? Not an expert, but my understanding was ~1000V for AC, but much lower for DC

The definition depends on the context. When discussing risk of electrical shock, below 50V is usually considered low voltage (and safe).

You can kill yourself with much lower voltages than that, assuming the power supply is capable of delivering the amps.

Wow, I didn't realize they went that high. Then yes, with the current output of a battery pack, I can see why people are worried.

The voltage is not particularly the issue. Petrol cars have a high tension line for the spark plugs that goes to over 30,000 volts.

About that, do cars attempt to shut down engines, fuel intake and electric pathways when detecting a collision ? I remember Liquid Gas vehicles having an emergency outlet to avoid fire/explosions. In Tesla's case that would be cutting the battery off the circuit and maybe putting it into a 'fast drain' mode ..

You can't just "shut down" electric pathways. Not exactly. There is a manual cut that first responders need to make to sever the high voltage circuit before they can work on the car. However there's still capacitors, converters and the battery itself that remain dangerous especially if they've been compromised.

As for "fast draining" the battery, where would the power drain to? That's exactly the problem.. NOT giving the power a path to go when you're working on the car.

This is not much of an issue with most cars because the electrical systems are low voltage (12V car battery). With Tesla it's enough to cause major injury or death with one touch if you complete the circuit.

Watch the video, it explains all this. http://www.youtube.com/watch?v=ntK3rvVl2Qw

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 interesting way to fail if you forced it to discharge that fast (bypassing all the safeguards).

[1] 3.06e8 J / (4.181(J/(g * k)) * 75K) = 976,000g ...I probably got that wrong, it's been a long time.

[2] I mean, their main job is getting rid of large concentrations of heat, right? ;)

That's the amount of energy needed to bring nearly 1000 kg of water from 25°C to 100°C, but not enough to begin the phase transition from liquid to gas (i.e. start boiling).

The heat of vaporization of water (i.e. the amount of energy required to convert liquid water at 100°C to vapor at the same temperature) is 2260 J/g. So to completely boil your metric ton of water at 100°C would require an additional 1000 kg * (2260 J/g) = 2.3 GJ, which is 627 kWh!

At 85 kWh, the Tesla's battery contains enough energy to completely boil off 119 kg of water starting at 25°C [0], which is still pretty impressive!

[0] 85 kWh / ((4.181(J/(g * K)) * 75 K) + (2260 J/g))

While that's true, I don't think it's what the parent meant. Colloquially, when we say to boil water we don't mean until the vessel is dry, just until a roiling boil is reached (this is typically how we cook pasta).

If the 1000 kg is heated uniformly, this is not enough energy to bring it to a "roiling boil". There will be no bubbles.

Right. It's a good thing stoves/ranges heat from the bottom!

You're forgetting convection.

Ah very true. Knew I was forgetting something.

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.

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

Wolfram Alpha puts it at 1/5th the energy in a typical lightning bolt... Absolutely nuts.

> 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.

As the video explains, even when the battery has been isolated there are other components that remain electrically hazardous such as capacitors and the converter.

Also there is the possibility that the battery itself may be physically compromised in an accident, e.g. it could protrude into the cabin (it sits right under it). Not much you can do to isolate it then.

Caps hold energy, sure, but if you're cutting through one it will self-short, which will be momentarily unpleasant but should not be close enough to anyone to actually injure them. What would be more worrying would be to cut through a circuit without completing a current flow path for the capacitor as that would leave open the possibility of someone accidentally completing the circuit themselves. But even this is not a large risk if you use conductive tools (which will absorb the brief current surge) or wear anything insulating.

The concern with the inverter-converter is mostly due to the fact that it's hooked up the battery. If the battery is already open-circuited then the inverter-converter should just be a dumb block, modulo any residual energy left over in a rectification circuit or something.

And it won't get easier since "we" want battery capacity to increase.

That's a very big question and probably only time will tell. Without getting into it too much, a very basic difference is..

Gas can explode like a bomb but (a) it needs an ignition source and (b) there can be visible signs when the fuel is leaking to let you know to take extra precautions (like spray fire retardant). You can actually get fuel on you and you'll be fine.

High voltage systems don't (usually) explode, but they have lethal amounts of energy stored that can find its way into your body if you complete a circuit. Furthermore in a mangled wreck there aren't necessarily visible signs when a component is electrified. You find out the hard way.

Basically Tesla deserves props for making an extremely strong car. That's what was tested here. But the spin is they're claiming "safest car" while completely side-stepping the high voltage safety issue.

> Gas can explode like a bomb but (a) it needs an ignition source and (b) there can be visible signs when the fuel is leaking to let you know to take extra precautions (like spray fire retardant).

And (c) if it's a diesel car (very common in europe), good luck getting it to explode.

Want to scare your friends? Put out a lit match or cigarette using Diesel fuel.

Diesel fuel requires a lot of heat to combust. Diesel engines don't contain spark plugs, they heat the fuel by compressing the air that the fuel is atomized in.

>Basically Tesla deserves props for making an extremely strong car. That's what was tested here. But the spin is they're claiming "safest car" while completely side-stepping the high voltage safety issue.

That's not a side-step. IIHS doesn't test for this, and Tesla is not beholden to do so.

Technically they only claimed "ACHIEVES BEST SAFETY RATING OF ANY CAR EVER TESTED" which is completely true.

The "unaware of any Model S or Roadster occupant fatalities in any car ever" is also a pretty strong argument for actually being the "safest car" too.

There isn't really a good way to quickly and safely dump all the energy from a battery the size of the Tesela's. Think about it: to drain in an hour, the battery would have to source 65kW continuously, converting all that energy into either heat or light somehow.

About that, do cars attempt to shut down engines, fuel intake and electric pathways when detecting a collision ?

Some do, and a lot of people don't know about that. It can trip in small accidents too so sometimes people can figure out why their car won't start when it seems perfectly fine. Check your manual to see if you have it and how to reset it, it's good to know.

That said, my grandfather was in an accident where he slid off an icy roadway and flipped his Toyota truck. It didn't trip the cutoff (may not have had one) and the engine continued to run upside down. He had to reach in (after he had crawled out) and turn off the ignition. It surprised him because he had never owned a car that was fuel injected.

Most cars automatically shut down fuel supply to the engine when a collision is detected. Even if it's just a minor hit the engine can't be started again without clearing the collision warning from the computer.

Thanks, now I wish to know more about the protocols and checks in car controllers.

Shut down fuel supply is code for turn off the fuel pump.

This can be done all mechanically, scroll down on this page to see a deconstructed inertia switch. http://www.therangerstation.com/tech_library/InertiaSwitch.h...

Fast draining those batteries would likely cause an enormous amount of heat.

This.

Batteries have internal resistance. They're generally rated for a certain level of drain (amperage), which, if exceeded, will go over the thermal limits for the battery.

In the case of a Tesla, you'd risk being fried (current) _and_ roasted (heat) at the same time.

Better simply to keep the energy contained.

Recycling the same astroturfing from the Prius a decade ago. Boring. Try something new, or people remembering last time around are going to LOL not get scared as intended.

While it's true these concerns are probably overblown in the eyes of the public (it's not something they need to worry about). It's absolutely not 'astroturfing' from my perspective (as someone who may need to cut one of these up some day).

I very much appreciate the amount of effort Tesla has put into producing training materials for working with their vehicles.

Good thing regular cars don't contain high voltage components or volatile, flamable fluids that can cause intense fires and even explosions...

High voltage? Do you mean the 12V battery that can't shock you, or the spark ignition that won't do much more than startle you?

I've had numerous sparks jump from distributors and plug wires through my hand. They just make your hand numb/tingly. If the jump went in your left hand and out your right, there might be some cardiovascular risks, but that's nothing compared to the risks of 400V @ god knows how many amps.

Car explosions have been thoroughly busted by Mythbusters. They are as busted as "Enhance!"

Car fires are very real and nasty, though.

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 and there's crushing the opponents. One shouldn't gloat in the latter case, but this case deserves an exception.

Congratulations Elon and the team on tremendously nice engineering!

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

Anyone else notice Tesla's flying rear view mirror that nearly hit the dummy in the face? Maybe they forgot to apply the little alcohol wipe before gluing it on the windshield :).

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.

Tesla makes an impressive vehicle, but it is unfair to compare a ~$80K machine to a ~$30K one.

A fairer comparison would be to a BMW 5xx or Mercedes E class. Tesla may still fair better but not by as huge a margin.

Having said all that... wow, that is a surprisingly huge difference in results!

Same test with a Jeep Liberty:

http://www.youtube.com/watch?v=z4T1BimfUf4

Lexus RX350:

https://www.youtube.com/watch?v=mAz6ZMeIC9s

Lexus ES350:

https://www.youtube.com/watch?v=4l0o9MTY0JA

BMW 5-Series:

https://www.youtube.com/watch?v=-r20YfGYhvc

Mercedes C-Class:

https://www.youtube.com/watch?v=zTkbG64V4tQ

https://www.youtube.com/watch?v=sg0ubBqhZjg

It also looks like, in an accident, the lights on the Tesla start to flash.

The lights wouldn't appear to be flashing, they are blinking at a faster rate than the human eye can see and thus just to a person appear dimmer than they would if they were on full power.

Most dimming of LED's is done with this super fast blinking technique because LED's can be either on or off unlike incandesant bulbs. https://en.wikipedia.org/wiki/Pulse-width_modulation

That's an Accord coupe, the B pillar is more thick than a 4-door version, wouldn't that mean the sedan would score even worse?

Okay, that's impressive. The Accord isn't a bad car per se, but its dummy is clearly having a much worse day.

> There's winning and there's crushing the opponents.

Crushing the opponents while your car remains uncrushed in the test (or the least crushed).

That's what you get when you ask the rocket scientist to make you a car.

If you ask a rocket scientist to make you a car that passes the crash test ratings alone, they'll build you a tungsten dump truck.

If you're going to win, you might as well reach the destination without noticing that you've had a collision.

The goal of a crash test is not to keep the car intact, it is to keep the driver intact. On "keep the car intact", today's cars do way more badly than those of the 1950's.

> On "keep the car intact", today's cars do way more badly than those of the 1950's.

I don't think that is true.

http://www.youtube.com/watch?v=joMK1WZjP7g

Nice video, deserves my upvote, but I am going to call it just anecdata ;-), so that I can add some partial counterarguments.

The video is a commercial, so they will have chosen an impact angle and speed that makes the newer car look best). For example, you can see that the newer car is heavier than the old one from the video; its front wheels still move forward when the wheels of the old one already go back. Because of that, the new car has a much longer braking distance than the old one. Things would have looked relatively better for the old car if they had chosen a collision with a concrete wall.

Also, Reading http://en.wikipedia.org/wiki/Crumple_zone, the crumple zone was patented in 1952; chances are this 1959 car doesn't have a good one.

If its crumple zone is bad or absent, chances are that the older car would have survived way better in a frontal collision, where the beam carrying the engine would be elastically compressed without deforming permanently.

That would be just the car, though; those old cars could be lethal at incredibly low speeds, for example by impaling them on their non-collapsible steering column.

Great video. Pretty clear that both occupant and vehicle fared worse in the 1950s. (Although after a serious collision I doubt many people care much how the car looks.)

You also have to factor in a lot cars in those days didn't have, and weren't required to have seat belts. This safety feature alone has saved thousands of lives regardless of how safe the car is.

Another interesting crash test is the Smart car. Youtube some videos of it. Due to its small size it hardly has any deformation zones and has to be built as a hard cage. It looks quite intact after a crash but i don't think the passengers inside would be.

Rather my car take the impact than myself.

I believe one of the tests is crashing into a wall that yields very little, so the tungsten dumptruck would fare poorly, exciting as it would be to drive.

EDIT: this one: http://youtu.be/V5R80yUUVNk

The wall at left in that video is, at most, four dump trucks in volume and perhaps constructed of reinforced concrete (density ~2,500 kg/m^3)?

A single solid tungsten dump truck would have almost twice the mass of the wall. Even with a completely inelastic collision, the wall's going to shatter and move. For a 35 mph collision, I think you're right, that wall would ultimately bring the truck to a halt from friction with the ground. At higher speeds, I think the truck might make it through.

Tungsten is quite dense (19,300 kg/m^3). Such a truck would have a mass of >400 metric tons (2 x 3 x 4 m x 19 tons/m^3), or >247 Toyota Tacomas (2013 extended cab, curb weight 3560 lb --> 1618 kg).

The truck would be terrifying to drive, once you got it going. I don't know how you'd turn.

Alas, Youtube is short on tungsten dumptrucks, but this may suffice. In a demonstration, a truck uses its brakes to stop after obliterating a few cars. The truck is driven by a real person.

http://www.youtube.com/watch?v=h6TRqjjnO58

>400 metric tons

So around the max takeoff weight of a 747, with approximately as heavy duty a wheel setup I assume. That would be quite a truck.

Given a heavy enough tungsten truck...

I imagine NASA's crawler transporters would score exceedingly well on most of these tests, assuming the technicians survived.

Well considering they had a max speed of two miles an hour unloaded, you could probably jump off and get a beer before the crash happened.

"We're gonna crash, noooooooooooooooooooooo"

Flashbacks of Austin Powers and a steam roller...

Is it too far fetched to say he benefited from SpaceX research ? if so, this kind of gene transfer reminds me of Apple years when the iPhone benefited from iPod and Mac hard and software knowledge to leapfrog the competition, and then later helped the MBA do it again.

I would imagine this is less the case than Subaru and Saab benefiting from their own aeronautical research. Unlike Subaru and Saab, SpaceX is a different company with different engineers than Tesla.

Rather, I think this speaks more to Elon Musk's uncanny ability to attract and hire good engineers.

Similarly: "during validation of Model S roof crush protection at an independent commercial facility, the testing machine failed at just above 4 g's."

Is there some kind of diagram that explains how this works? I can't really see how this works just by imagining it.

Not exactly a diagram but the a video of the test: http://www.youtube.com/watch?v=dz2FMfv-CSc

A bmw 3 series (not full frontal): http://www.youtube.com/watch?v=4XG8BQt4sHY

Modern crash engineering is really impressive (that under-car view is really neat!)

This 2009 vs. 1959 offset crash shows how much things have changed:

http://www.youtube.com/watch?v=joMK1WZjP7g

It's really unfair to compare offset and frontal crash tests. You can't draw any conclusions by comparing the two. For years, auto manufacturers were able to perform competently in the frontal crash test, but when the offset test was introduced, the failure rate went through the roof.

I don't mean to diminish the performance of the Tesla Model S. It is, without qualification, an incredible car. I just don't think comparing it to the offset video of a BMW are relevant.

Wow. The windshield doesn't even crack.

You have to consider that there is no engine in the front - just empty space for storage. That changes the game of frontal collisions completely.

0:58 - 1:07 of the first video link... the car continues to attempt to propel itself into the wall.

Only for 0.3 seconds. The first camera shot at normal speed show's how quick this is all happening.

It sounds like it's a special band running around the car, made of multiple layers of aluminum with space in between each layer. The layers crumple and transfer impact across the side of the car like a ski resting on soft snow.

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/McLaren%20F...

F1 @ 40mph: http://www.youtube.com/watch?v=mUPq760LC00

I'm more than willing to acknowledge Tesla has fantastic results, especially for the price... but that top spot still belongs to my childhood automotive idol. ;)

You may well be right -- I know nothing about car safety -- but I thought you might enjoy this fun bit of Elon-Musk-McLaren-safety-related info:

After selling PayPal (long before the Tesla Roadster), Musk bought a McLaren F1, subsequently crashed it, and walked away unscathed. Here's him talking about it!

https://www.youtube.com/watch?v=mOI8GWoMF4M

As others have said — it's the side impact test that makes the Tesla Model S so notable.

There again, the F1 has one major advantage — it has a monocoque, and should therefore to do better than most (unibody) cars on the market. But to make a monocoque out of something like carbon fibre you need a lot of money!

(Good examples of this are the two Audi R18 crashes at Le Mans in 2011: http://www.carmaautolife.com/wp-content/uploads/2011/06/Rock... is one after a ~200mph crash and spin into crash barrier. He got out on his own two feet. Pretty much everything but the monocoque is gone. Videos can be found on YouTube of both this and McNish's crash. At night, with so little video available, could scarcely tell what car it was…)

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".

That's a single test. It's not surprising that there's a car out there that can do better than a Tesla in one of the IIHS tests. However, to get a 5 star rating, you have to get a "good" on all of the tests, which I am very confident the F1 does not do.

Being a rear-engine design gives both the Tesla & the F1 a huge advantage in frontal tests. But I'm willing to bet that a side impact test or a roll over test will show much different results...

That's amazing! I had no idea the F1 was so sturdy. My assumption (probably common) is that these super light exotics disintegrate when hitting large insects, let alone walls.

Many of them do, although there is the notorious story of an Enzo that got literally torn in half on CA 1 and both people inside walked away.

Here's the story: http://en.wikipedia.org/wiki/Stefan_Eriksson#Car_crash

You have big part of why in your statement. "super light" Mass * Velocity. Less mass, means less energy to dissipate.

It's very likely that the Model S could also be driven away after the tests, since the engine sits on the rear axle and the only electronic component in the front is the 12v battery.

I don't know about the F1 these days but the P1 starts at million dollars. I would hope that for anywhere close to that cost they could build in protection for me from my own stupidity when I inevitable try to drive Decker Canyon at full speed. ;)

If you're curious, like I was, about the side pole test, here's a video of the Tesla:

http://www.youtube.com/watch?v=BBvH3lysmJA

Here's a Prius for comparison (4 stars):

http://www.youtube.com/watch?v=Yc0uUx2T37k

That looks like the difference between waking up sore the next morning and waking up in the hospital the next morning. Pretty impressive how well the Tesla does given how little space is available to absorb the blow.

Minor nitpick: your second link is a Prius c, which is quite a bit smaller than a regular Prius, and more like a Yaris aside from the drivetrain. Still a decent example of a "normal" car in any event.

That's a Prius C, the new super-small one based on the Yaris chassis. Given its ultra-low-budget roots, four stars is actually really impressive. Yeah, the Tesla is better, but it's a newer, heavier, and far more expensive design. It should be better.

Here's a Prius v. Looks worse than the c.

http://youtu.be/GNZ5ojGRiRU

That fallacy is debunked by every sports car ever.

Sports cars have always made sacrifices in this regard. The first being simply that real sports cars are half the size of a modern saloon, which gives much less room for crumpling.

The fallacious argument is newer/more expensive = more secure. Every car has compromises.

Newer, heavier and far more expensive, and of course even that doesn't guarantee good safety ratings, it just makes it a lot easier to achieve.

I'd gladly go up against every sports car that the Tesla beats off the line and the quarter mile. Which is quite a few.

Err... what? If what you are trying to say, in the most roundabout way possible, is the Tesla accelerates fast- sure. But so does a top fuel dragster, and neither is a sports car.

A sports car is a small, usually two seat, two door automobile designed for spirited performance and nimble handling. Sports cars may be spartan or luxurious but high maneuverability and minimum weight are requisite.

-- Wikipedia

(Notice it doesn't say a damn thing about horsepower)

That's surprising to me. I have always considered a sports car to have a bit of extra power. I guess I'll have to open my mind a bit.

I suppose that would be very difficult to define.

I think sports cars have a higher power-to-weight ratio typically, but again if this was a prerequisite for a sports car then older cars would lose their sports car status over time.

Alternatively, a cheap car intended to be sporty made by a low-end manufacturer could be disqualified from being a sports car because of higher-end manufacturers throwing off the curve.

They usually do, but extra power isn't what make them sports cars.

That seems like such a shit way of doing the pole test and introduces too much randomness to be uniform across all cars. The much better way is to keep the car stationary on a moving platform like ANCAP does http://www.ancap.com.au/crashtesting

is randomness not good? you aren't going to be driving around on a rail irl

Not when you're trying to make an objective comparison with a small number of trials.

If the test was always exactly the same, designers could optimize the car design for that precise impact force at that precise point.

The ability to compare different cars is probably more important than preventing designers from sticking a five foot thick plate of metal on the precise diagonal of the crash test, which would be obvious. A major part of crash testing has to be the forces felt by the test dummy, so there's not a whole lot designers could do to reduce those forces in exactly one direction without also reducing them in other directions.

Favorite quote: "[T]he exact number is uncertain due to Model S breaking the testing machine"

My favorite was "While this is statistically unlikely to remain the case long term, Tesla is unaware of any Model S or Roadster occupant fatalities in any car ever."

There aren't that many on the road to begin with. To put this into perspective: during 1990-1994 there were 5 fatalities in Volvo 240s with 186000 cars on the road [http://www.iihs.org/externaldata/srdata/docs/sr3009.pdf]

Also the roof holding 4 additional cars, that's cute http://www.aronline.co.uk/blogs/wp-content/uploads/2011/09/v...

The test machine broke at 4, not the car.

They picked a wimpy machine if it broke at 4x. Here's one that can apply 159 tons of force (about 80x the weight of a Tesla).

http://www.overbuilt.com/products/car-crushers

Correct me if I am wrong, but that doesn't look particularly like a calibrated testing machine.

Yeah, I'm pretty sure this is the type of thing they use for crushing cars for scrap metal, not testing how much pressure it takes.

"It is possible to game the regulatory testing score to some degree by strengthening a car at the exact locations used by the regulatory testing machines. After verifying through internal testing that the Model S would achieve a NHTSA 5-star rating, Tesla then analyzed the Model S to determine the weakest points in the car and retested at those locations until the car achieved 5 stars no matter how the test equipment was configured." - This is how you take on the Big Three

So, does anyone want to give odds that Tesla will be a disruptive force in the automotive industry throughout the next decade?

If they manage to remain at or near profitability through the continued scaling of Model S production and the introduction of the Model X next year, then things could get very interesting when they release their infamous 'third-generation', mass-market vehicle.

Yeah, I remember beign told at the end of the 90's that if you'd bought 100 shares (~$2000) of Microsoft stock at IPO and sold in '99, you'd have cashed in well over a million dollars.

Tesla gives me that kind of feeling at the moment.

It probably won't be to the same extent as Tesla's market cap is already quite high. So I can't see them splitting quite as much as MS. But on the other hand, I think they're definitely a stock to hold on to for quite a while and see what happens.

The problem with your thought process is that, unlike microsoft and google or apple, most traders and analysts already treat the company as if it can do no wrong. Analysts calling for price targets of 130 or 160 were predicting sales of 200K+ units per year 2-3 years out, which is a really aggressive target given the size of the addressable markets. On the other hand, it was only in 2011-2012 that wall street gave Apple its due credit.

Which is not to say that the stock couldn't jump further, but as of now it's already in the same ballpark as big auto in terms of market cap (as of close today, Tesla market cap is 17.6B while Ford's market cap is 65B and GM's market cap is 51B).

In short, a good buy requires two things:

1) Potential for growth

2) Potential for growth that everybody else hasn't already recognized

Tesla is dandy for #1, but isn't looking too hot on #2.

the market cap comparison is somewhat misleading because clearly there is substantial probability of Tesla selling many more cars, once they release mass market versions. They have created enormous brand value. if they successfully offer a mass market car, their market cap could easily be higher than Ford.

I bought several tens of thousands of TSLA shares at ~$17/share when they went IPO; my wife still chides me I didn't buy more.

Assuming at least 20k shares, you made >$2.5mm off that investment, using $340k of capital?

Not bad.

Haven't sold all of it, so its not fully realized. Sometimes it pays to go all in.

by gaming the fucking test?

No, it sounds like first they made sure they could get the 5-star rating on the test, and then they kept working so that the car had 5-star safety even if they changed the test. They could have just gamed the test to get an inflated score but instead made a car that isn't just built to pass the test.

The crash test results, including the videos, are available here: http://www.safercar.gov/Vehicle+Shoppers/5-Star+Safety+Ratin...

And even more crash test data and videos: http://www-nrd.nhtsa.dot.gov/database/aspx/vehdb/testtablede... http://www-nrd.nhtsa.dot.gov/database/aspx/vehdb/testtablede... http://www-nrd.nhtsa.dot.gov/database/aspx/vehdb/testtablede...

Elon has mentioned how much they prioritized safety in designing the Model S. I'm glad to hear that their efforts have paid off.

This is great news for Tesla as it opens their market even larger as the car can appeal to those seeking safety and not just performance or lower carbon footprint.

> Elon has mentioned how much they prioritized safety in designing the Model S.

Definitely a smart move. If nothing this gives them a smaller attack surface against attacks from Tesla's competitors. You can bet they would have attached like leeches to any minor safety flaw. For example, say, a Tesla car caught on fire and its batteries ended up electrocuting a fireman -- there would be no end in sight to the letters to the editor from "concerned citizens" about fireman's family and how we won't think of his children.

Extra effort for increased safety is definitely worth it, if anything at least for marketing purposes.

>Extra effort for increased safety is definitely worth it, if anything at least for marketing purposes.

More to the point, traffic deaths are a /real danger/ - more people are killed by falling appliances than by terrorism, and we seem to think it's worth spending huge amounts of money, going to war with the rest of the world, and giving up many of our own rights to fight terrorism. For most of us? Terrorism is not a real threat. For most of us, especially us middle-class Americans, If we die before we get old? there is a pretty large chance that death will be in a traffic accident. If we want to increase safety, we should be spending thousands of dollars on auto safety for every dollar we spend "fighting terrorism"

I'd sooner spend the money on preventing night time rage from standing on Lego than on preventing terrorism. So much of the effort is utterly counter productive. I guess ago safety is probably a better use than my suggestion though.

I know what you and Elon mean here with the word "prioritized," but it's impressive just how many things on the Model S were a priority. Safety, performance, style, technology, experience, efficiency, etc. Where it seems most manufacturers set a few priorities and then fail to deliver on some of those, it seems the Model S had several and met them all. Of course, I end up sounding like an evangelist saying that.

Indeed. I read the article, and immediately sent it to my not particularly technically inclined, but very safety conscious sister.

> The Model S lithium-ion battery did not catch fire at any time before, during or after the NHTSA testing. It is worth mentioning that no production Tesla lithium-ion battery has ever caught fire in the Model S or Roadster, despite several high speed impacts. While this is statistically unlikely to remain the case long term, Tesla is unaware of any Model S or Roadster occupant fatalities in any car ever.

I can't help but feel this is a bit of a jab at Boeing. :)

It might be, but also consider that lithium-ion batteries do have a reputation, and catching fire or exploding would be high on the list of things that anyone wanting to sow doubt about the safety of an electric car might bring up, so pre-empting it might be worthwhile for that reason too.

one can only guess what Airbus sales reps talk about in private with their potential clients :)

I think it's both, as what you mention is quite true and Musk has made some comments about "getting it right" after the Dreamliner battery issue.

I wasn't sure exactly what was meant there. At first, I thought it meant that it was statistically unlikely for there to be no battery fires in the long term, but I think it's just referring to occupant fatalities.

I believe it refers to fatalities as this almost exact quote has been said by Elon before in a recent Q&A session.

Likewise. A paragraph break would have made it a little more clear.

No it was a jab at GM, google volt fire.

There is a meme in the conservative rage-o-sphere that electric car batteries catch on fire all the time.

"Of note, during validation of Model S roof crush protection at an independent commercial facility, the testing machine failed at just above 4 g's. While the exact number is uncertain due to Model S breaking the testing machine, what this means is that at least four additional fully loaded Model S vehicles could be placed on top of an owner's car without the roof caving in."

I don't have any frame of reference for how this compares to other vehicles, but damn, that is impressive.

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.

Let's see if I remember my high school physics. Making all sorts of assumptions and simplifications here:

F = mv / dt (equation of impulse for zero final velocity)

F = mg (newton's laws)

mg = mv/dt

g = v/dt

9.8 = v/0.5

v = 4.9

Therefore, the car can be travelling no more than 4.9m/s at impact to survive.

mgh = 0.5mv^2 (initial gravitational potential energy = kinetic energy at impact)

gh = 0.5v^2

h = (0.5v^2) / g

h = (0.5 * 4.9 * 4.9) / 9.8

h = 1.225

So, assuming that it takes 0.5 seconds (a wild ass guess) for the car to go from freefall to rest, the car can withstand a drop of 1.2 metres without deforming the roof.

Mind you,

Ouch, units, please! Leaving the units out of your physics math is like, well, not wearing a seat belt when driving a car.

Anyway, I'm afraid that 0.5 seconds to come to rest is way too long. Toss it into the equations of motion and:

    d = 1/2 at^2
    d = 1/2 9.8m/s^2 (0.5s)^2
    d = 4.9m

In other words, decelerating at 4 gees for half a second means you decelerate over nearly five meters.

I think we're better off starting at the other end of the stick and making a wild guess that the roof can move 10cm without being permanently deformed. Then:

    d = 1/2 at^2
    0.1m = 1/2 4 * 9.8m/s^2 t^2
    t = 0.0714s

To figure out the height, we can notice that a and t will be inversely proportional for any given velocity (double the time, halve the acceleration needed), and so, for a given initial or final velocity, the subexpression at^2 is directly proportional to the change in acceleration. In other words, if we assume that the roof can withstand 10cm of deflection, you can drop the car from 40cm up.

Thanks, much appreciated. Sorry about the lack of units. If it's any consolation, I included them in the text surrounding the calculations. :)

Depends upon how squishy the roof/substrate is. The acceleration-to-height or compressive stress-to-height conversion is not well-defined in general.

If you're optimizing for dropping a car on its roof from a specified height, it's probably better to drop the car on its roof.

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.

yeah, but from any meaningful height?

do they really hoist a car upside down to 10, 15, 20, 30 feet and then drop it on its roof? because that's what the OP was referring to.

A car could certainly flip up into the air quite a few feet while rotating and then land on the roof.

Elon Musk clearly writes these things himself. That, or he's got a bunch of other folks like him working at Tesla.

Either way, it's exciting times. It's fun to be inspired by a company. To find something that keeps getting better as it unfolds...

Or they work together at creating them. I.e. he writes a draft, gets it fleshed out, and he applies some finishing touches.

Sure. I guess what I mean is I can see his hand in the work. (Or at least I've convinced myself of that.)

Tesla's PR is many things, but it's not safe. It feels plain and unadorned and yet genuinely enthusiastic and precisely bold.

I used to be worried that Musk's hand was too heavy on the tiller. Now I'm just enjoying the show.

> Tesla's PR is many things, but it's not safe. It feels plain and unadorned and yet genuinely enthusiastic and precisely bold.

In most big companies the PR people have to cover their asses, but don't have too much ownership of what they say. Whereas for Tesla someone who's not afraid is calling the shots.

Exactly. It is an incredibly refreshing departure from how things are normally done in Corporate America.

And I think it's worth it for them to spend CEO time on it.

Because the difference is not just between people reading good PR vs mediocre PR, but whether people will actually read it. (I.e. if it's not worth doing well, might as well not do it.)

Having a fearless leader one can look up to must also be fucking awesome for employee morale.

It works for the military.

> Elon Musk clearly writes these things himself.

What the fuck? Get a grip, PR is _an_ industry.

You're right - that phrasing is sloppy. I'm sure there's a kick-ass PR team behind this.

But it smells different than normal PR. It actually contains surprises and a conversational tone and it reminds me of Musk himself. Giving an interview, for instance.

This could be me projecting onto it, or maybe Musk really does drive PR more than you'd expect for a company at this stage. Or maybe his team is able to pull this off on their own. Either way it's fun to watch.

And Elon Musk is notoriously unconventional. Automotive manufacturing is also an industry, and he doesn't keep with tradition there either.

Now, do you actually have anything intelligent to contradict this suggestion? You've made several negative comments on this article, and although I agree Tesla's hype is large and growing, you haven't actually added factual content to the conversation.

Very impressive. One really cannot over stress that there is a lot of car that you "don't need" in the front and back if you don't have a big engine but using it for energy absorption is a certainly valid use. So far the only complaints my friends have had with their cars has been the "constant" updates to the software.

I can't believe people would complain about the updates to the software. They are more rare than iPhone dot releases and come with real benefits. Maybe they were pulling your chain.

It is certainly possible they were yanking my chain, would not be the first time. Our CTO Greg had an issue with the 'low power' recharge situation which was fixed by a later software update. I've not manageed to get the building owner to install a charging station in our parking lot yet alas.

What kind of updates come in Tesla software releases, and also how do they get into the car? I've actually never thought about this at all.

You get all the updates over the provided 3G connection the car has included. Here are some of the release notes:

http://www.teslamotorsclub.com/showwiki.php?title=Model+S+so...

I started with 4.2 and am on 4.5 now.

It helps that it weighs 4,600 pounds. (More than a thousand pounds heavier than the Volvo S60 they compare it to.) Heavier vehicles always do better-- which is why SUVs survive crashes so well.

First: SUVs don't survive crashes particularly well -- they're very prone to rollover, which generally makes for a bad day for the occupant. I've witnessed multiple large-SUV vs. Camry (mid-sized sedan) accidents where the Toyota fared far better (walk away vs. ambulance or worse).

Weight can be a factor, especially in multiple-vehicle accidents, where the heavier vehicle simply has more momentum and kinetic energy. In a multiple-vehicle accident, the larger vehicle experiences lower g-forces, and the occupants lower forces.

Collisions with a stationary object (the basis for the NHTSA tests) largely takes this factor out of the equation. More mass can _still_ result in better survivability if it means more material around the driver, but here the choice of materials and engineering matter far more. Look at the comparison tests of classic (1950s/1960s) and modern (post 1980 and more recent) vehicles:

http://www.youtube.com/watch?v=joMK1WZjP7g

I don't know the GVW of the Bel Aire, but I suspect it's rather higher than that of the Malibu.

Of course, modern vehicles with poor engineering and materials can also fare badly:

http://www.youtube.com/watch?v=g5SRyG6UR2A

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 also interesting to note that pickups can fare quite poorly (the Nissan Titan Crew Cab is among the worst vehicles listed), and even within the same manufacturer, lager models aren't necessarily safer (Mazda 3 at 52 deaths/million miles, Mazda 6 at 60). The error bounds and total miles (exposure) on a number of the larger SUVs are also large and small respectively, suggesting a possible data collection limitation.

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.

Thanks for the clarification.

For some stats:

In 2009 there were 10.5 million accidents, and 35,900,000 motor vehicle fatalities. Your odds of dying in any given accident are 0.3%.

In 2013 projections were for 1,203.6 billion vehicle miles travelled. Travel mileage has actually been declining slightly (about 1%/year) since the 2008 depression.

You could expect to travel 33,526,462 without a death, on average.

http://advisorperspectives.com/dshort/updates/DOT-Miles-Driv... https://www.census.gov/compendia/statab/2012/tables/12s1103....

I got hit by a Nissan Titan: http://imgur.com/a/nIMOP#0

I can't get over how intact the interior is. Any injuries to you?

What were the crash parameters? Speeds? Head-on? (Looks like it).

Your car was a Subaru something or other?

2012 Subaru Impreza Premium.

I had a slight gash on my head that bled for a little bit, and I have a dislocated clavicle near my breast bone.

I was driving 20 Mph, taking a left turn, the Nissan Titan was doing (by the drivers accounts) 45 - 50 Mph. Practically head-on.

According to the fire department, police and EMT's that arrived on the scene it was a miracle how in-tact the interior was, and that I walked away from it. The insurance adjuster at first wouldn't believe me when I told him to start working up paperwork for totalled while also telling him I had walked away from it. He ended up later calling me while looking at my vehicle, and I quote, "Are you sure you are okay?"

The guy that towed my vehicle from the accident site was surprised to see me after I was released from the hospital looking for my keys (house keys are on the same key ring), he hadn't been told about my status by the cops or anyone, and had assumed I was in crit-condition in the hospital.

Subaru saved my life, and for that I am extremely happy.

Damn. Glad you're OK and thanks for sharing.

I swear the longer I drive the more freaked I get by it, even with all the tech a well-designed vehicle can wrap you in.

Great link. What is the rationale for reporting death rates in terms of vehicle-years, rather than rate per mile traveled?

What if SUVs just get driven less (due to poor mileage, only being taken out in the snow...)

> What is the rationale for reporting death rates in terms of vehicle-years, rather than rate per mile traveled?

Vehicle-years can be determined directly from vehicle registration data. Miles traveled would require a lot more guesswork.

With the increasing prevalence of smog checks as a registration renewal requirement, and the inclusion of a highly detailed electronic vehicle record (see for example California's BAR-90 and subsequent records, Washington and several other states have similar records), odometer data is available and is used heavily by insurance companies in assessing risk for a large number of drivers.

"Heavier vehicles always do better"

You are wrong. At least in the perspective of crash tests.

In a crash test against a wall (equal amount of kinetic energy transferred to the wall and to the vehicle), a lightweight vehicle does better than an otherwise identical but heavier vehicle. This is because its mass is less, therefore there is less kinetic energy to dissipate.

However in road crashes, heavy vehicles fare better because the heavy vehicle transfers more kinetic energy to the more lightweight vehicle.

NHTSA crash ratings are well known to not reflect this difference. But the point remain that heavy vehicles are disadvantaged compared to lightweight vehicle, and the fact the Model S does so well despite its weight is a testament to its good crash resistance.

I don't know much about the mechanics or engineering of the Model S, but I'm going to take a gander and say that much of that extra weight comes from the battery pack (and other parts of the non-traditional drivetrain), which isn't a (huge?) factor in a crash test (though I could be wrong).

Just checked - yep - the battery weighs an estimated ~ 545kg or 1200 lbs [1].

I'd expect the structural components to actually be lighter than competitors, given that they're fabricated with aluminum vs steel.

[1] http://www.teslamotors.com/fr_CA/forum/forums/model-s-batter...

How much does the gas tank, motor, radiator, transmission, etc. in a normal car weigh? Have to subtract that out of the 1,200lbs to see how much extra is added.

Mid-Range Estimates:

Engine: 300 to 450 pounds Transmission: 120 to 140 pounds Gas Tank: 20 to 25 pounds Radiator: 20 to 30 pounds

So, roughly 460 to 645 pounds. Add 110 pounds for 15 gallons of gas. The comparison is a little more difficult than this though, because the batteries just store energy. The Model S still has a (416hp) motor, there are a few other differences (regenerative vs standard brakes) and equivalencies (inverter vs alternator).

Yep, it gets a bit tough, but that 460-645lbs range seems like a decent stab at it. I don't get the impression that the Model S's motors are all that heavy compared to the rest of this stuff, but I could be wrong. I'd also wager that the Model S needs a full set of mechanical brakes for emergency purposes, since it still needs to be able to stop safely even if all the electronics suddenly quit while going down the highway at 70MPH. And then there's the question of whether you compare against a 416hp motor, or a less powerful gas motor that would be more typical for a car that size....

A Chevy 383 can make about 400hp+ in about 620 pounds. If we choose all our numbers for comparable cars that are highly in favor of the Tesla, we're still only likely going to match the weight of the Tesla's battery pack alone.

The Model S curb weight is 4,647 pounds. A Cadillac STS, which is 5" narrower but very nearly the same in every other dimension as the Model S is only 3,922 pounds. That leaves the Model S 725 pounds heavier, still quite a bit of difference.

It's in the ball-park though. Your assessment seems pretty fair. I've seen some call the Tesla's weight "insane" though.

My old (still current gen) Volvo S80 T6 weighed 4,400lbs IIRC. I assume that's "dry" weight. Since a Model S is always "dry" aside from a gallon of wiper fluid or the like they probably weigh just about the same on the road. And the Model S is a bigger, faster car.

My Jeep Grand Cherokee (with the panoramic sunroof option I didn't actually have) weighed 5,500lbs. Again, I assume like motorcycle manufacturers that car manufacturers are listing the "dry" weight. So that baby is probably over 3 tons wet when optioned up.

The Cadillac seems on the light side for it's class. Even so, "wet" the difference in weight is probably one passenger. Despite it being a smaller car (5" actually seems pretty significant IMO, that's 5" less wiggle room to stay in your lane!).

That's (I assume) the worst-case-scenario highest capacity Tesla. Performance is far in excess of most cars on the road already. Capacity with smaller battery packs will surely improve. It seems like weight can only go down from here, and it's not out of line with it's competition as is.

The 20+ gallon tank in my old Jeep Grand Cherokee would add over 300lb to the "wet weight". It also took (IIRC) an insane 7L of oil. So that stuff adds up.

I don't think that test wall moved more because of the weight of the Tesla.

But it's not the heaviest car ever made. So they're doing something exceptionally well other than making it heavy. I'd imagine much of that weight is in the batteries and electric motors.

What is the calculated correlation between NHTSA vehicle safety score and vehicle weight. I don't know this, but suspect that it is a less significant factor than you imply. Add that the Tesla is 1000lbs+ of battery.

Safety is engineering and materials. More materials help, of course, but more materials without the engineering simply equals more kinetic energy. There are vehicles from big SUVs to tiny SMART cars doing superbly on crash tests now.

Weight has a small impact, but you have to remember the low of geometric scaling.

Amusing that you mention the Smart Fortwo.

http://www.iihs.org/news/rss/pr041409.html

  ARLINGTON, VA — Three front-to-front crash tests, each 
  involving a microcar or minicar into a midsize model from 
  the same manufacturer, show how extra vehicle size and 
  weight enhance occupant protection in collisions. These 
  Insurance Institute for Highway Safety tests are about the 
  physics of car crashes, which dictate that very small cars 
  generally can't protect people in crashes as well as 
  bigger, heavier models.

  "There are good reasons people buy minicars," says 
  Institute president Adrian Lund. "They're more affordable, 
  and they use less gas. But the safety trade-offs are clear 
  from our new tests. Equally clear are the implications when 
  it comes to fuel economy. If automakers downsize cars so 
  their fleets use less fuel, occupant safety will be 
  compromised. However, there are ways to serve fuel economy 
  and safety at the same time."

http://www-nrd.nhtsa.dot.gov/Pubs/808569.pdf‎

  Large vehicles have historically been more stable and 
  provided more protection for their own
  occupants than small ones, but they presented a greater 
  hazard to other road users. Between 1985
  and 1993, the population of light trucks - pickups, sport 
  utility vehicles (SUV) and vans - increased
  by 50 percent in the United States. Since the major 
  downsizing of passenger cars during 1975-82,
  light trucks have had a substantial and growing weight 
  advantage over cars. By 1992, the number
  of fatalities in collisions between cars and light trucks 
  exceeded the number in car-to-car collisions
  In car-light truck collisions, 80 percent of the fatalities 
  are occupants of the cars. That raises the
  question whether the growth in the number and weight of 
  light trucks is having an adverse impact
  on the safety of passenger car occupants and other road 
  users, possibly exceeding any safety benefits
  of the vehicle-weight increases for the occupants of the 
  trucks.

Vehicle safety is complicated, obviously, and vehicle weight isn't the only variable of merit, obviously. (See http://energy.lbl.gov/ea/teepa/pdf/aps-ppt-wenzel.pdf‎ )

But all things being equal, in a head on collision between two identical vehicles, save that one weighs a thousand pounds more than the other, the heavier car is going to win.

But all things being equal

Rater irrational requirement, given that we're talking about engineering. It short circuits the entire conversation.

In any case, I find it odd that you find my reference of the Smart "humorous". While the IIHS held their results as demonstrating bigger versus smaller, in actual reality it primarily demonstrated more expensive versus less expensive -- there is no great confusion that less expensive cars often sacrificed safety, and this was true at all vehicle sizes (e.g. some early budget Kia minivans and SUVs were deathtraps). It seems to have mostly passed now that even economical cars like the Cruze are posting stellar results.

But let's assume that a greater weight, by itself, equals better safety. So would that Volvo do better than the Tesla if they filled the trunk full of concrete blocks?

Note that I didn't say that weight doesn't correlate with safety, but that it doesn't correlate nearly as strongly as you seem to imply -- e.g. saying that a large sedan is 1000lbs heavier than another large sedan in no way, I would guess, leads to a conclusion that it will also do better in safety tests.

Isn't this old news? (http://www.treehugger.com/cars/tesla-model-s-gets-5-star-saf... was posted two weeks ago: http://www.treehugger.com/cars/tesla-model-s-gets-5-star-saf...)

Should be, as these test are done before they can enter the market.

Nope. These tests were done in July 2013, but deliveries started June 2012.

5-stars across the board is old news (lots of cars achieve that), but the fact that it's the safest car tested is new.

"the front section that would normally contain a gasoline engine is used for a second trunk."

I guess somebody has veto'd "frunk". Oh well.

In the UK & Australia it would be a "froot".

Or a "hat"

Yes, but as a result, extra attention was probably given to the entire front of the vehicle, which is also usually the case for mid-engine supercars.

The big reason why the small overlap test is being focused on (aside from cars doing so well in every other test) is because of the reliance of manufacturers relying on an engine block (though really, the front reinforcement bar) to provide some assistance in bearing and distributing crash forces in more serious front impacts. When a single A-pillar has most of the force to bear, it's not been pretty for nearly every other car on the market.

All the auto clubs around cars with empty front sections call them frunks.

I am really proud of Elon and his crew.

For someone who has made a first pass at making a car he sure has set the bar very high. The performance, quality and safety of this vehicle show that anything is possible.

However, on the flip side, it shows how uncompetitive the U.S. market has become. It takes vast sums of money to compete with the big 3.

I look forward to Elon pushing the limits in space and with the hyperloop.

Is there an automotive safety engineer in the room? I'd be eager to get expert commentary on these results.

The safety test results sound amazing. Tesla is also strong in the marketing department.

Just trying to maintain healthy skepticism. These results seem very exciting.

Tesla S is an excellent car. Loved it when I sat in one.

What came to light in Germany some years ago, with a heated discussion, is that automotive companies seem to optimize their cars towards specific tests. The discussion raged around what tests are more realistic, with those that let the car makers look bad (foreign tests) being "not realistic".

The way cars collapse and fall apart at crashes is absolutely amazing. Just over 30 days ago I was involved in a head on collision with a Nissan Titan full-size pickup truck WITH cargo in the bed, and walked away from an accident the EMT's, fire fighters, and police all told me it was almost impossible I did. The adjuster didn't believe me when I told him the state of the car, but when he did go out to check it out he called me and asked me if I was sure I was alright...

Here are pictures: http://imgur.com/a/nIMOP#0

I was driving 20 Mph, turning left at a traffic light, the pickup truck was driving (according to the driver) 45 - 50 Mph, although the adjuster and off-duty police suggest he may have been driving faster.

---

One thing I will note though, my car is significantly cheaper than the Tesla... and fares extremely well in the NHTSA tests.

There have been several real-world crashes of the Tesla S, and none, as far as I know, have resulted in any injuries to the driver.

One was even a head on crash at fairly high speeds which killed the other vehicle's driver. The Tesla S driver walked away. Tesla never fails to amaze me.

Source on the head-on crash story?

http://www.youtube.com/watch?v=QtgTcoT1yRo

I was mistaken. Two people were killed in the other car, and the Tesla driver was taken to a hospital with minor injuries. Still, amazing aftermath to a terrible accident.

I found this one: http://www.liveleak.com/view?i=821_1367344455

I've always found the star safety ratings confusing especially when I've noticed compact cars getting the same stars as large cars.

I'd like to just see each model ranked by number of fatalities per mile driven. Wouldn't that make a lot more sense?

Is such a statistic available anywhere?

They exist [1] but can be misleading because different kinds of people buy different kinds of vehicles. So muscle cars and 4x4s have higher crash rates than minivans and economy sedans mainly because of the people that drive them.

[1] http://www.iihs.org/externaldata/srdata/docs/sr4204.pdf

Thanks! I guess you could still use it to compare between say minivans?

How do pedestrians fare when hit by a Tesla? I'll save my cheering for when they have a self driving one so I no longer have to worry about drunk or distracted drivers.

My guess is they would do pretty well. There is not a rigid engine right under the hood, the wipers mounts seem well protected under the hood, and no other protrusions really in the front. Euro NCAP provided pedestrian safety results, but the site does not work for me from here. You can go see if you want though if there is anything for the Tesla Model S there.

Here in Europe we use EuroNCAP, do you have any news about a testing by this laboratory? Google doesn't yield any interesting result.

I was in a European Tesla retailer this month or the last, and the person told me that no tests NCAP test had been made at the time.

it makes sense, but do they plan to make some?

I think they'd have to, once they set up Supercharger stations and go for the European market.

Is there not a way an emergency responder, or anyone else for that matter, could fully discharge a battery like the one on a Tesla? As ask coz back in the day before digital cameras became mainstream, we used to repair point and shoot cameras at the photo processing lab where I worked. A point and shoot camera has a capacitor for the flash that can give you a short but not insignificant shock, and to avoid it, we'd take a normal light bulb and use it to discharge the capacitor. I realize a cap batteries stores a lot more power, but couldn't some mechanism be built that does the same thing?

"While the exact number is uncertain due to Model S breaking the testing machine, what this means is that at least four additional fully loaded Model S vehicles could be placed on top of an owner's car without the roof caving in."

jeez.

couple that with this and it's safe to say these have been a good couple of months for tesla http://www.consumerreports.org/cro/news/2013/05/video-the-te...

> Of note, during validation of Model S roof crush protection at an independent commercial facility, the testing machine failed at just above 4 g's. While the exact number is uncertain due to Model S breaking the testing machine, what this means is that at least four additional fully loaded Model S vehicles could be placed on top of an owner's car without the roof caving in. This is achieved primarily through a center (B) pillar reinforcement attached via aerospace grade bolts.

lol, they broke the testing machine

How can I buy one of these? Is there a huge wait time?

And how does the performance compare to a regular consumer-level luxury 'sports car' like an audi?

From lowest end to highest end, the wait time is 3, 2 and 1 month. It crushes my old 911 C4.

Performance? https://www.youtube.com/watch?v=VLCdP6sMN9k#at=29

Seems a little disingenuous to bring up better rating than SUVs. SUVs of the same rating as cars still have a 4.5 times better survivability rate. The rating is for comparing similar cars hitting each other. A comparatively light and low to the ground car is not going to fare well vs. a heavy, higher off the ground SUV. That's just simple physics.

Okay, I am convinced this car is superb. How about we... build more of them? There is a Ford factory here in Australia that is due to be shut down in 2 years, it could be converted, and us Aussies would love to be able to buy this car. I personally promise to buy one if it is built here. The Aussie government might chip in as well.

Scaling up quality is not trivial. You can bet they are working on it.

I'm willing to bet that you've nailed the exact reason he's not doing SpaceX exclusively yet.

Love it when the goal is to be better than the best, nothing less is tolerated, and the engineering makes it so.

Maybe they should find someone try to hack into the system. I believe this computer based car will have the same virus problem as PC. If it has function to connect the internet via wireless network, things might be worse...

That's what you get when you think about your product first, and profit second. Musk wants to give the world a great car, not to make profit on cars. This breeds quality we see.

The Tesla is a great car but it's absolutely insane that American taxpayers are donating $7500 to allow rich people to buy $75,000 luxury cars.

The graphic below shows the statistical Relative Risk Score (RSS)

I do not think that acronym means what you think it means.

Well, they probably won't win out against the whole of the geeky internet.

> While the exact number is uncertain due to Model S breaking the testing machine...

The tone of this press release is perfect.

I keep fearing this guy is going to pull a John Gault on us. He's the closest thing to an Ayn Rand character I've seen in my lifetime. Too close for comfort.

Atlas Shrugged came out when I was entering high school and almost ruined me according to my dad back then (and he was a republican.) :-)

At $70,000+, it's still out of reach for most people.

Misleading title.

Elon is on a roll

Here are videos of model s crash tests:

Frontal - https://www.youtube.com/watch?v=dz2FMfv-CSc

Pole - https://www.youtube.com/watch?v=_Al3IUHt9Wc

Side - https://www.youtube.com/watch?v=nNyjiFmjfxw

The lack of critism in this thread is astounding.

Not surprising since this is about a celebratory post. There's plenty of time to criticize things on the internet, why the rush?

HN has a raging hard-on for tesla. It's not surprising, but I agree it's ridiculously one sided here.

Personally, I hope Tesla fail, and think they will.

> Personally, I hope Tesla fail, and think they will.

I think that without any kind of justification, this is completely unnecessary for HN, and downmodded you accordingly. Even though I agree that many comments here are one-sided, and haven't considered what the PR statement might be missing.

> Personally, I hope Tesla fail, and think they will.

Maybe, but you need to realize that the electric car is an obvious and timely technological development, and someone will produce a successful mass-market electric car. Why not Tesla? It's not as though they're making a lot of mistakes.

I don't believe electric cars are technologically better. Lugging a half ton battery around, then waiting for hours for it to charge doesn't seem that clever to me.

Of all the things that are banes of our lives these days, surely it's everything that runs on a battery.

Remember when phones would last a week or so on a charge? Now you're lucky if a smart phone lasts a day on standby. And people call it progress...

So no, I think the idea of having a massive battery in my car is horrible.

> I don't believe electric cars are technologically better. Lugging a half ton battery around, then waiting for hours for it to charge doesn't seem that clever to me.

Early internal combustion engines were also rather embarrassing, but this didn't hinder their adoption -- at the time they were a better choice overall.

Imagine the reverse situation -- imagine that electric cars took hold when they were first introduced in the early 1900s and saw a century of improvements. Then someone comes forward and says, "We have an idea! Instead of charging your battery all the time, you carry a tank of explosive liquid fuel with you wherever you go, and you burn the fuel as you drive."

Present battery technology is pretty terrible -- not very efficient, too heavy, low energy density, short life. But widespread adoption of electric cars will force technological improvements, just as happened with internal combustion engines.

If batteries improve -- greatly -- it will become self-evident that carrying a battery around is a better choice than carrying and burning liquid fuel, both for the environment and in a simple economic sense. At the moment, electric cars aren't an obvious improvement over an internal combustion car, but I think that will change.

In a hypothetical future with more wind and solar energy sources, and possibly fusion power in the long term, electric cars will make more environmental sense as well.

Take an AA battery. Now go back in time 30 years and look at an AA battery.

Identical. Why has battery technology not improved one bit in the last 30 years? Well, obviously there's a massive disincentive - the better the battery, the less people buy, but I don't think that's the main limitation.

I don't think conventional batteries can improve all that much more.

> Take an AA battery. Now go back in time 30 years and look at an AA battery. Identical. Why has battery technology not improved one bit in the last 30 years?

That's completely false. I might have said, "Look at a basic mousetrap 30 years ago. Now look at one today. Identical." What's missing is any examination of the alternatives. 30 years ago, there weren't any NiMH batteries, or commercial lithium-ion batteries (the latter were under active development), but they're now the primary power sources for portable devices, and lithium-ion batteries power the Tesla Model S.

> I don't think conventional batteries can improve all that much more.

And I don't think conventional thinking can improve all that much more. But I have high hopes for unconventional thinking.

"When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong." -- Arthur C. Clarke

> lithium-ion batteries (the latter were under active development), but they're now the primary power sources for portable devices, and lithium-ion batteries power the Tesla Model S.

What does that mean for the user. Do batteries today last twice what they lasted 30 years ago? Nope. Are rechargeable batteries any more viable today? Nope.

Even batteries in laptops only last a year or so before they are just dead and need replacing.

If you think battery technology has really massively improved in the last 30 years, please let me know what real world improvements there have been...

> What does that mean for the user. Do batteries today last twice what they lasted 30 years ago? Nope. Are rechargeable batteries any more viable today? Nope.

You are flat wrong on both counts. Modern batteries provide much more energy per size, weight and cost than their rechargeable predecessors. As to "viable", how can you make any kind of claim about batteries that didn't exist 30 years ago?

> Even batteries in laptops only last a year or so before they are just dead and need replacing.

Yes -- compared to no batteries and no laptops, 30 years ago. What kind of comparison do you think you're making?

> If you think battery technology has really massively improved in the last 30 years, please let me know what real world improvements there have been...

Today, batteries exist, and applications exist, that did not exist 30 years ago. Modern battery applications could not be filled by the technology that existed 30 years ago. How difficult is that to decode? Thirty years ago, the Tesla Model S could not exist, period, full stop. The battery technology didn't exist.

Chart of battery energy density by year:

http://www.akbars.net/images/battery%20energy%20density.png

My first laptop was an Amstrad PPC512 in the mid 80s - almost 30 years ago. I'm still not convinced batteries have come that far since then.

I'm actually thinking of going back to my nokia which has a battery that lasts a week on standby. Compared to modern smartphones which last a day.

You're right though - Inefficient bloated buggy software is becoming the driving force for requiring more power from batteries - going back to my original point - I don't want software running my car.

Agree to disagree eh

> I'm still not convinced batteries have come that far since then.

Then you're suffering from evidence immunity:

http://www.akbars.net/images/battery%20energy%20density.png

The above graph shows that batteries have improved enormously in the past 30 years -- they now have more than twice the energy density they had then. There are few products that have improved so dramatically. And more improvements are in the pipeline:

http://www.treehugger.com/clean-technology/new-lithium-ion-b...

Quote: "Breakthrough lithium-ion battery can recharge 1,000x faster than current tech"

> Agree to disagree eh ...

This is not a matter of opinion. It's a matter of fact.

"I don't want software running my car."

Too late. Every car since about 1993 is entirely reliant on electronic computers, and many were even in 1980. Most of them reprogrammable, though usually cumbersome to do so.

"I don't want software running my car."

Too late. Every car since about 1993 is entirely reliant on electronic computers--and many were much earlier. Most of them reprogrammable, though usually cumbersome to do so. Changing software during service is common these days--and the dealer may not even bother to mention it.

Tesla's use of software is pretty normal. Go sit in BMW 5 series, or a Ford Focus. All soft interface. Tesla's is just nicer, and not afraid of taking advantage of the fact that everything is software already.

"Waiting for hours for it to charge" is not accurate.

Actual On-Demand Refilling Stats:

- One hour at supercharging station

- Two minutes at battery swapping station

Tesla are actually building cars because the world is running out of oil, so if you want to drive in the future, then the car has to be electric because the price of oil is too expensive.

gargoiler00: As long as the Sun shines...

The supply of electricity however, is apparently limitless!!!

> The supply of electricity however, is apparently limitless!!!

Using solar, wind, hydroelectric and future fusion reactors, yes, it is.

Basically, yeah.

Why do you hope for that?

I'm guessing he shorted it at $40 like all the other smart people did.

Firstly, I don't believe electric cars are a good idea. Secondly, I absolutely hate the idea of cars so dependent on electronics and software.

My neighbour has an old dumper truck he lets me use, probably 50 or 60 years old. It starts every time, first time. There is literally nothing to go wrong on it.

Now contrast that with a modern car, where you need special tools to access the electronics unlock diagnostics. What about when cars have auto update software over wifi? What about when the government forces car makers to embed their own tracking software into them to monitor and spy on civilians.

Tesla isn't quite as bad as the idiotic self drive cars Google is pressing for (So they can drive you to a google advertiser), but they're in the same bucket of nastiness.

Thanks for answering. I respectfully disagree, but we can still have a civilized conversation.

> My neighbour has an old dumper truck he lets me use, probably 50 or 60 years old. It starts every time, first time. There is literally nothing to go wrong on it.

I guess apart from modern safety features and gas guzzling?

> What about when the government forces car makers to embed their own tracking software into them to monitor and spy on civilians.

Not necessary. People already carry cell phones.

I am actually looking forward to the self driving cars. Human error causes lots of accidents. But then, I don't own a car and probably never will.

Sorry for the sarcasm, but could it be because it runs out of batteries before hitting the test wall? :)

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