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Tesla Adds Titanium Underbody Shield and Aluminum Deflector Plates to Model S

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Re: Tesla Adds Titanium Underbody Shield and Aluminum Deflector Plates to Model S

#181
post #25

Earlier quoted context omitted.

Exactly why. They're gently poking fun that Tesla vehicles are extremely safe, especially compared to fires - and then sticking it to critics further by actually announcing improvements to further reduce the already very low numbers of fire and further increase the already highest rating ever for a safety check for a vehicle. Well done Tesla and Elon.

And yet, I can't help but feel they're being very, very defensive over it. I can't blame them, of course, given how something trivial like a car fire (trivial given the average frequency of them) is turned into a national news event. At the same time, Tesla's attention to quality and perfection and what-have-you will end up in them being heavily scrutinised. It's not that different from Apple in that respect; random…

Tesla is very, very defensive over this. This hasn't been stated explicitly, but it is very clear if you read between the lines of their PR initiatives.

According to statements from the company, the media coverage after the fires last year caused a sharp decline in the rate of Model S reservations. It has since recovered, but after these events Tesla started viewing poor public perception as an existential threat. The reasoning is that new and unfamiliar technology (battery propulsion) is scrutinized very, very closely and held to a much higher standard than the status quo. This is evident from the ridiculous headlines every time a Model S is involved in a fire. (Garage fires, house fires from unrelated accidents and the two floorpan fires + the high-speed crash referenced in the article). Poor public perception equals lower sales to an already skeptical public, and perhaps the second demise of the electric car.

A different strategy than the one Tesla is pursuing, would be to not change anything and just repeat the (correct) message that their electric cars are statistically much less likely to catch fire than a gasoline automobile. But this leaves them wide-open to PR attacks from skeptics and the established auto industry the next time an inevitable fire occurs. It's already been firmly established that there is a big PR machinery which will jump on any opportunity to call Tesla's technology into question - and there will be plenty of competition from the incumbent manufacturers. They're playing it safe.

(Tl;dr: Yes.)

Re: Tesla Adds Titanium Underbody Shield and Aluminum Deflector Plates to Model S

#182
post #155

Assuming the underbody plate is only 2mm thick, the Model S is suddenly accelerating 5% slower. To put it otherwise, every acceleration now takes at least 4% more energy (> 0.01 kWh for an acceleration from from 0 to 65 mph). Sounds great for city driving.

Can we see your calculation and reasoning or did you make the numbers up?

Re: Tesla Adds Titanium Underbody Shield and Aluminum Deflector Plates to Model S

#183
post #94

Did anyone else notice a screw coming detached from the titanium underbody shield after the impact of the three ball tow hitch, you can also see the shield bend on the impact of the concrete block and the hole where the screw was. It would be kind of ironic if this actually made the car less safe.

If my car went over a concrete block with nothing more than a dent in the underside I'd be very happy.

Re: Tesla Adds Titanium Underbody Shield and Aluminum Deflector Plates to Model S

#184
post #160
post #102

Earlier quoted context omitted.

GM is currently recalling 1.6M cars which can accidentally turn off while driving: http://www.thewire.com/business/2014/03/gm-recall-mary-barra... (this has apparently resulted in a number of deaths, as the power steering stops working)

Not only were they aware of the problem, they did the calculus and decided to release a brand new model knowing this issue effected . http://consumerist.com/2014/03/25/gm-knew-chevy-cobalt-ignit...

"Take the nubmer of vehicles in the field, A, multiply by the probabilty rate of failure, B, multiply by the average ouf-of-court settlement, C. A x B x C = X. If X is less than the cost of a recall, we don't do one."

Re: Tesla Adds Titanium Underbody Shield and Aluminum Deflector Plates to Model S

#185
post #3

"However, to improve things further, we provided an over-the-air software update a few months ago to increase the default ground clearance of the Model S at highway speeds" I know this is not specific to Tesla, but it's still really cool. :)

I'm sure there are strict security measures and a rigorous testing regime in place, but still the idea of some anonymous engineer being able to push an over-the-air update to my fast moving, two-ton lump of metal makes me a little nervous. (Tin foil hat mode) Imagine the implications of some malicious third party gaining access to that process.

The updates aren't installed while the car's moving. You see a dialog box asking if it's OK to install at 3am (or you can change the time, or wait til later.)

Re: Tesla Adds Titanium Underbody Shield and Aluminum Deflector Plates to Model S

#186

Earlier quoted context omitted.

But titanium is less dense than steel, hence preferred when weight is important. For an electric car, weight is paramount, I would think.

Actually, nope! While it requires more initial force, that extra energy due to added mass is stored in kinetic energy, and contrary to popular belief, it does not affect efficiency. There was actually a myth busters episode about this. Electric cars would store this added energy in their regenerative breaking, so it shouldn't affect energy consumption. Also, the added weight of steel over titanium would be negligible…

I would think that 100 extra pounds, coupled with the inherent energy loss from inefficiency, would be a significant factor in the car's range. That's 75% of one extra passenger.

This site (http://www.jurassictest.ch/GR/) lets you plot a course for several EV models and set up some parameters such as weight. Adding a passenger to a Tesla knocks 9 Km off the range, according to them.

Re: Tesla Adds Titanium Underbody Shield and Aluminum Deflector Plates to Model S

#187

"We believe these changes will also help prevent a fire resulting from an extremely high speed impact that tears the wheels off the car, like the other Model S impact fire, which occurred last year in Mexico. This happened after the vehicle impacted a roundabout at 110 mph, shearing off 15 feet of concrete curbwall and tearing off the left front wheel, then smashing through an eight foot tall buttressed concrete wall…

> This is the most ridiculous thing I've ever heard. Do you mean ridiculous as in you believe that he is exaggerating, or ridiculous as in it is amazing that the car held up so well? I doubt that he would simply make up verifiable facts concerning a specific, well publicized accident to make his company look better. That said, it is quite clear from these facts that this driver is lucky to be breathing today regardle…

It's ridiculous how much emphasis the media placed on the fire while ignoring the extreme speed and consequently minor injuries involved in the crash.

Re: Tesla Adds Titanium Underbody Shield and Aluminum Deflector Plates to Model S

#188

It's really difficult to emphasize how excessive this is. As a mechanical engineer, I knew just by reading the title that this is really excessive, because the titanium alloy used is definitely a marketing stunt. Titanium has unbelievable tensile strength for its weight, but there's no good reason to make an "underbody shield" out of titanium except for publicity. It would make way more sense to use steel (and maybe…

" the shields prevented any damage that could cause a fire or penetrate the existing quarter inch of ballistic grade aluminum armor plate that already protects the battery pack" Ballistic grade aluminum armor plate... If there is one thing Tesla does well it is publicity. I know there are high strength steels but it seems like they want something that is strong and light. If it sounds like something impenetrable to t…

> Ballistic grade aluminum armor plate...

That's from the same marketing phrase-book as 'aircraft-grade aluminium'.

Lightweight armour ( e.g. personal protection ) uses ceramic plates.

Heavy armour ( e.g. tanks ) still uses steel alloys with composite and plastic layers. There were a few AFVs with aluminium armour, such as the M113 and Sheridan, but ballistic protection was restricted to small-arms and light shrapnel. A Sheridan could be ripped apart by a 12.7mm DhSK.

Re: Tesla Adds Titanium Underbody Shield and Aluminum Deflector Plates to Model S

#189
post #102
post #67

Earlier quoted context omitted.

Let's not forget that Tesla recently issued a recall for 29,000 charging adapters because they would overheat and catch on fire. http://www.nytimes.com/2014/01/15/automobiles/citing-chargin...

GM is currently recalling 1.6M cars which can accidentally turn off while driving: http://www.thewire.com/business/2014/03/gm-recall-mary-barra... (this has apparently resulted in a number of deaths, as the power steering stops working)

And just to give a sense of the orders of magnitude:

    1,600,000
       29,000

Re: Tesla Adds Titanium Underbody Shield and Aluminum Deflector Plates to Model S

#190
I just had a thought that Elon Musk owning both Tesla and SpaceX, the next logical step would be an electric powered airplane or a chopper. It could be an airplane/chopper that would glide down to safety in case of a mechanical failure, or crash land on rough terrain without fear of catching fire. That would disrupt aviation industry like never before.
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