Jump to content


Photo
- - - - -

Is the Diesel dead for autos?


  • Please log in to reply
297 replies to this topic

#101 gruntguru

gruntguru
  • Member

  • 6,603 posts
  • Joined: January 09

Posted 03 May 2016 - 05:48

 

Find me a 1600kg petrol car that can do 0-60 in 6s and can do 60mpg.

Some Golf models are getting close  http://www.auto-data...ar&car_id=18412

 

Coming Miller cycle versions will be up to 20% better on fuel (initially only up to 150 hp models). http://www.gizmag.co...er-cycle/43067/

 

No doubt in my mind that petrol cars are closing in on your targets - probably with some help from F1 and Mahle TJI.



Advertisement

#102 BRG

BRG
  • Member

  • 16,122 posts
  • Joined: September 99

Posted 03 May 2016 - 16:27

BMW cutting the ground from under Tesla's feet?



#103 Canuck

Canuck
  • Member

  • 2,049 posts
  • Joined: March 05

Posted 03 May 2016 - 17:41

Given the i3 is now almost at the 200-mile range, it is a potential competitor the Tesla Model 3 (albeit a smaller one)

Hardly cutting the ground from under them. That's like saying the Fiestas are stealing the ground from under BMW's M3.

And sweet Jesus that thing is ugly. What is it with efficient car designers and the preponderance for the ugly?

#104 gruntguru

gruntguru
  • Member

  • 6,603 posts
  • Joined: January 09

Posted 03 May 2016 - 22:43

Model 3 specs are a bit different eg 0-60 less than 6 seconds vs 7 seconds for the i3. https://recombu.com/...o-go-mainstream

 

i3 is pretty expensive here in Oz AUD$64k for the "short range" version. US prices seem to be US$40k+.



#105 Greg Locock

Greg Locock
  • Member

  • 5,550 posts
  • Joined: March 03

Posted 04 May 2016 - 07:50

Given the $/$ exchange rate a 50% AUD markup is about right, no? 



#106 BRG

BRG
  • Member

  • 16,122 posts
  • Joined: September 99

Posted 04 May 2016 - 09:54

 What is it with efficient car designers and the preponderance for the ugly?

That is indeed a mystery that I have often wondered about.  It seems that for designers any radical departure from the norm has to be seen to be 'different'.  One reason to applaud Tesla, whose EVs look just like regular cars and are none the worse for it.



#107 saudoso

saudoso
  • Member

  • 6,693 posts
  • Joined: March 04

Posted 04 May 2016 - 10:35

That is indeed a mystery that I have often wondered about.  It seems that for designers any radical departure from the norm has to be seen to be 'different'.  One reason to applaud Tesla, whose EVs look just like regular cars knockoff Maseratis and are none the worse for it.


Fixed that for you   ;)


Edited by saudoso, 04 May 2016 - 10:37.


#108 Talisman

Talisman
  • Member

  • 5,032 posts
  • Joined: January 05

Posted 04 May 2016 - 12:14

That is indeed a mystery that I have often wondered about.  It seems that for designers any radical departure from the norm has to be seen to be 'different'.  One reason to applaud Tesla, whose EVs look just like regular cars and are none the worse for it.

 

Actually this is one area where Tesla and other EVs disappoint me.  Electric powertrains have many packaging advantages so I want the makers to show me what they can do with them, not just build dull hatchbacks and saloons like petrol and Diesels.



#109 Canuck

Canuck
  • Member

  • 2,049 posts
  • Joined: March 05

Posted 04 May 2016 - 15:37

Actually the Tesla sedan is a 7-seater if I'm not mistaken. The rear-facing seats aren't for tall people mind you but you can get 2 kids and 5 adults in that thing. It probably still has more luggage space than my Expedition.

#110 mariner

mariner
  • Member

  • 1,762 posts
  • Joined: January 07

Posted 04 May 2016 - 16:31

The Uk Autocar magazine recently did a full road test of the latest Tesla Model S. They were very impressed, which given their adualtion of German Premium cars is a big compliment.

 

They did proper acceleration runs to full speed which make interesting reading. It does 0 - 100 mph in 9.1 seconds in " insane" mode. Thats pretty amazing  and effectively matches a BMW M5 to 100 at 9.0 seconds . BTW they couldn't do Tesla's  claimed sub 3 seconds to 60 but apparently Tesla say in the small print thats with a short rolilng start!

 

One important aceleration point is how rapidly the Tesla acceleration drops of beyond 100 mph . Having matched an M5 to 100 mph it takes 66% longer to go from 100 mph to 140 mph than the BMW.( 14.5 seconds vs 8 seconds).

 

So the linear electric motor torque which is so impressive at low speeds has an equally linear drop off as well.


Edited by mariner, 04 May 2016 - 18:34.


#111 MatsNorway

MatsNorway
  • Member

  • 2,720 posts
  • Joined: December 09

Posted 05 May 2016 - 14:05

2013-tesla-model-s-electric-sport-sedan-

 

About Mariners post.

 

I guess a gearbox is needed :p

 

Im guessing there is possibilities to get more out of the Tesla motors but so far full size cars got a thing or two to learn from the RC cars. They have timing tuning and "boost" on the regulators. Boost is electronic timing advance most likely. That said all of this is expensive so your probably better of just trowing in a bigger motor and/or gearing it higher.


Edited by MatsNorway, 05 May 2016 - 14:06.


#112 gruntguru

gruntguru
  • Member

  • 6,603 posts
  • Joined: January 09

Posted 05 May 2016 - 22:13

Apart from needing another gear to get back into the power band, the Tesla would surely have an inferior power/weight to an M5 anyway. The Model S was not conceived to compete in the M5 category.

 

Its stunning acceleration from low speeds is greatly assisted by AWD, wide power band, superior launch characteristics of electric motors, and lack of gear shifts.



#113 404KF2

404KF2
  • Member

  • 6,399 posts
  • Joined: October 99

Posted 06 May 2016 - 04:54

Insane mode is not the 2.8 second mode....no, that is Ludicrous mode so..... I am not surprised that Insane mode didn't get under 3.0 seconds.



#114 Talisman

Talisman
  • Member

  • 5,032 posts
  • Joined: January 05

Posted 06 May 2016 - 09:35

2013-tesla-model-s-electric-sport-sedan-

 

About Mariners post.

 

I guess a gearbox is needed :p

 

 

Why have a bonnet at all?  The only reason cars have them is because the bulky ICE and transmission has to be directly connected to the driven wheels.  Electric cars don't have this problem and therefore the bonnet on the Tesla is unnecessary and relatively impractical for storage space.  Why not push the cabin forward to an extent not possible in a conventional car and give us interior space not seen this side of a bus?  Why not push the boat out a little and show us the kind of architecture that will become possible with electric cars?

 

Given that people who buy Tesla S's are early adopters and relatively open minded I don't think they'd have lost out by making the design more progressive.  They'd have sold anyway.  As it is I have difficulty telling the Tesla S apart from the Jaguar XF which is as conventional a design as you can get.  Its a missed opportunity IMO. 


Edited by Talisman, 06 May 2016 - 09:35.


#115 GreenMachine

GreenMachine
  • Member

  • 1,361 posts
  • Joined: March 04

Posted 06 May 2016 - 10:38

How would that affect survivability in a front end hit?

 

Good point, but there may be other ways of redesigning the electric car.



#116 MatsNorway

MatsNorway
  • Member

  • 2,720 posts
  • Joined: December 09

Posted 06 May 2016 - 15:41

It also needs to not look like ****, remain aerodynamic, have a easy entry into the cabin(seated where you are today relative to the front wheels) and have an effective crumple zone..To name a few. Cars are fairly figured out. Thats why all the shapes are similar even tho the hardware underneath chances.

 

The high roof cars is in my opinion a good way to get more space without getting a massive car. If your not into the sporty aspect i see no reason to buy a sedan. VW touran was imo what most should have gotten. Problem is ofc. some higher milage due to the bigger frontal area. But worth it due to better overview across the board.

 

This chance has been happening gradually on sedans too, the newest BMWs and Audis are giant cars that have a high roofline and very high sides. The high sides is a bit of a design thing but also aids in safety. Modern cars makes my rustbucket feeling like a sports car..


Edited by MatsNorway, 06 May 2016 - 16:21.


#117 Talisman

Talisman
  • Member

  • 5,032 posts
  • Joined: January 05

Posted 06 May 2016 - 16:09

It also needs to not look like ****, remain aerodynamic, have a easy entry into the cabin and have an effective crumple zone..To name a few. Cars are fairly figured out. Thats why all the shapes are similar even tho the hardware underneath chances.

 

Aerodynamics and aesthetics apart its clear that even with ICE PUs there is a massive spread in shapes.  Vehicles like the Toyota Previa with the engine underneath the cabin are able to push the driver forward so the legs are ahead of the front axle as do all vans and trucks whilst maintaining an effective crumple zone so this isn't the reason the Tesla is the shape it is. If tiny cars such as the Smart or iQ whose entire length is probably not much longer than the bonnet on the Tesla S can have effective crumple zones there is no reason Tesla can reduce the length of the bonnet considerably or do away with it.

 

Tesla have been deliberately conservative with the shape as have Nissan, BMW etc (although the garnishing on BMW's electrics is eyecatching) because customer expectations are of a car designed with an ICE in mind.  Current expensive ICE saloons have a long engine bay to fit in large capacity ICEs therefore the Tesla is the shape it is to fulfil our visual expectations of a car in that price range.

It is little different to the first cars looking like horse drawn carriages with the horse removed and replaced with the petrol engine.  It took about 30 years before cars shook off their horse drawn visual heritage and started to look as if they had been designed purely for petrol propulsion.  I would have expected that with electrics the electric car makers would be distinctly braver and lead customer expectations rather than following it.



#118 GreenMachine

GreenMachine
  • Member

  • 1,361 posts
  • Joined: March 04

Posted 06 May 2016 - 22:01

This is the technical forum, so it's is not surprising that this part of the discussion neglects the customer.  Fairly obviously, Tesla wants customers to associate its offerings with 'quality', and one of the simplest ways of doing this is to make them look like what the customers think of as quality - the styling cues of high end bimmers, mercs etc.

 

Cutting edge or even revolutionary design will appeal to a certain market, but then for the rest you not only have to sell the car, you have to sell the styling.

 

Innovation will come, given the packaging options these cars provide, but perhaps it will be a while.



#119 Lee Nicolle

Lee Nicolle
  • Member

  • 9,504 posts
  • Joined: July 08

Posted 07 May 2016 - 00:34

Just reading Macs [Magoo] Motor City Garage and it seems that Tesla has again posted a loss. How long can they continue  selling cars at a loss. Large expansion plans but not making money?? :stoned:



Advertisement

#120 gruntguru

gruntguru
  • Member

  • 6,603 posts
  • Joined: January 09

Posted 07 May 2016 - 02:38

Quite a while yet I would say. Depends how large the loss.



#121 bigleagueslider

bigleagueslider
  • Member

  • 1,233 posts
  • Joined: March 11

Posted 07 May 2016 - 05:46

Just reading Macs [Magoo] Motor City Garage and it seems that Tesla has again posted a loss. How long can they continue  selling cars at a loss. Large expansion plans but not making money?? :stoned:

Tesla cars are similar to the iPhone in that people buy them as a status symbol. However, while almost everyone can afford to pay a couple hundred dollars to buy an iPhone, very few can afford to pay $80K+ to buy a Tesla. And more importantly, Apple currently makes a profit margin of around 40% on every iPhone they sell. Tesla has an annual negative cash flow of over $500M and $1.2B cash remaining, based on their last yearly financial report. Their quarterly report issued this week noted a loss of $75M and a significant drop in S model sales.



#122 Canuck

Canuck
  • Member

  • 2,049 posts
  • Joined: March 05

Posted 07 May 2016 - 18:50

Tesla cars are similar to all consumer goods in that people buy them as a status symbol. However, while almost everyone can afford to pay a couple hundred dollars to buy an iPhone while making monthly payments on the balance to their carrier, very few can afford to pay $80K+ to buy a Tesla, Porsche, BMW, Mercedes, Cadillac, Audi, Infiniti or Lexus.. And more importantly, Apple currently makes a profit margin of around 40% on every iPhone they sell. Tesla has a GAAP gross margin of 22%, an annual negative cash flow of over $500M and $1.2B cash remaining, based on their last yearly financial report. Their quarterly report issued this week noted a loss of $75M and a significant drop in S model sales from Q4 2015 (which beat their prior best quarter by 48% and beat Q4 2014 by 75%) to Q1 2016 (which itself was almost 50% higher than Q1 2015) with a 10-fold increase in Model X deliveries over Q4 2015.

 

Fixed that for you.

 

Tesla_sales.jpg

 

I might suggest that the anomaly is Q4 2015

 

So where's all the money going? The battery plant in Nevada - still ahead of schedule, and the Tesla X SUV production line for which demand is appears to be outstripping supply. As those investments come into production (the X already has), the margins will start to increase as well.



#123 BRG

BRG
  • Member

  • 16,122 posts
  • Joined: September 99

Posted 07 May 2016 - 20:42

So where's all the money going? 

 

Interest and repayments on fixed assets (land, buildings, plant), maintenance and utilities, inventory, staff costs, marketing costs, sales network, etc.  There are so many up front costs that have to be made before a single cent of income comes in.  That's why startups are such a risk.



#124 Greg Locock

Greg Locock
  • Member

  • 5,550 posts
  • Joined: March 03

Posted 07 May 2016 - 23:38

Developing a whole new platform is probably costing 500 million a year. 



#125 BRG

BRG
  • Member

  • 16,122 posts
  • Joined: September 99

Posted 08 May 2016 - 18:20

Then there are the costs of type approval and homologation in each market.

 

And the cost of cheating the emissions tests.  Oh, wait a minute....  :lol:



#126 gruntguru

gruntguru
  • Member

  • 6,603 posts
  • Joined: January 09

Posted 08 May 2016 - 22:29

Zero??? Yeah they gotta be cheating.



#127 bigleagueslider

bigleagueslider
  • Member

  • 1,233 posts
  • Joined: March 11

Posted 09 May 2016 - 03:43

Fixed that for you.

 

Tesla_sales.jpg

 

I might suggest that the anomaly is Q4 2015

 

So where's all the money going? The battery plant in Nevada - still ahead of schedule, and the Tesla X SUV production line for which demand is appears to be outstripping supply. As those investments come into production (the X already has), the margins will start to increase as well.

From TSLA's SEC 8-K released on May 4th 2016: "..Our Q1 non-GAAP net loss decreased 34% sequentially to $75 million, or $0.57 loss per share based on 133 million basic shares, while our Q1 GAAP net loss was $282 million or $2.13 loss per basic share....".  I would ignore non-GAAP numbers.

 

 

Global_sales_Tesla_Model_S_by_quarter.pn



#128 mariner

mariner
  • Member

  • 1,762 posts
  • Joined: January 07

Posted 09 May 2016 - 16:27

I will second bigleaguesliders comment on the non GAAP numbers , usually put in reports to bamboozle analysts and optimists.

 

If  we do a very simple calcualtion Tesla lost $22K per car in Q1 2016 on a retail of , I think, $70k. Using a 10% cost/volume curve they need to triple Q1 volume on the Model S to 36,000 units per quarter to break even bottom line. That is about 150K units per year or 50% of Cadillac sales - certainly do-able but then its no longer a niche " cool" product.

 

One thing maybe worth mentioning , working capital is a permanent funding requiement for companies and as they grow they eat up working capital. So the idea that Tesla wil somehow magically stop consuming cash as it grows will only be true if it sharply cuts its capital investment and  R+D spending as it adds products.


Edited by mariner, 09 May 2016 - 17:14.


#129 MatsNorway

MatsNorway
  • Member

  • 2,720 posts
  • Joined: December 09

Posted 09 May 2016 - 19:18

Amazon sells Kindles with a loss and make money. So some come back on parts and service related stuff?



#130 saudoso

saudoso
  • Member

  • 6,693 posts
  • Joined: March 04

Posted 09 May 2016 - 22:05

Amazon sells Kindles with a loss and make money. So some come back on parts and service related stuff?

The analogy would be valid if Tesla was the electricity provider. I have a kindle and spend around $30 a month on it. Just fuel is spent at that rate in a car.



#131 Canuck

Canuck
  • Member

  • 2,049 posts
  • Joined: March 05

Posted 10 May 2016 - 00:38

I wish I paid $30 a month for fuel. :(

#132 imaginesix

imaginesix
  • Member

  • 7,371 posts
  • Joined: March 01

Posted 10 May 2016 - 02:33

I wish I paid $30 a month for fuel. :(


Not to stray off topic but have you considered one of those new electric cars?

#133 saudoso

saudoso
  • Member

  • 6,693 posts
  • Joined: March 04

Posted 10 May 2016 - 10:03

I wish I paid $30 a month for fuel. :(

I mean monthly expenses/product cost.

 

But I guess you got it and just couldn't help it.



#134 Canuck

Canuck
  • Member

  • 2,049 posts
  • Joined: March 05

Posted 10 May 2016 - 12:39

Not to stray off topic but have you considered one of those new electric cars?

Bah. Nothing but a marketing gimmick and chock-full of failure-prone (and pointless) technology. It's not like you'll be able to fix the regen braking system with duct tape and a hanger when you're stranded 300 kilometres north of the Arctic Circle. You'll die.

Edited by Canuck, 10 May 2016 - 12:40.


#135 bigleagueslider

bigleagueslider
  • Member

  • 1,233 posts
  • Joined: March 11

Posted 11 May 2016 - 03:31

I will second bigleaguesliders comment on the non GAAP numbers , usually put in reports to bamboozle analysts and optimists.

 

If  we do a very simple calcualtion Tesla lost $22K per car in Q1 2016 on a retail of , I think, $70k. Using a 10% cost/volume curve they need to triple Q1 volume on the Model S to 36,000 units per quarter to break even bottom line. That is about 150K units per year or 50% of Cadillac sales - certainly do-able but then its no longer a niche " cool" product.

 

One thing maybe worth mentioning , working capital is a permanent funding requiement for companies and as they grow they eat up working capital. So the idea that Tesla wil somehow magically stop consuming cash as it grows will only be true if it sharply cuts its capital investment and  R+D spending as it adds products.

According to TSLA's recent 8-K, production in Q1 2016 of X models was well short of expectations at 2659 vehicles. There was also the interesting statement that $57M of Q1 revenues came from ZEV credits. I sincerely wish Tesla well with their business, but from what I see in their financial statements it looks they have a big challenge going forward. Especially as the novelty of owning an $80K EV fades and S/X model sales fall, revenues from taxpayer subsidies are eliminated, the company makes the transition to selling large numbers of low/negative margin vehicles, and ther numerous competing vehicles offered by existing OEMs.


Edited by bigleagueslider, 11 May 2016 - 03:33.


#136 Canuck

Canuck
  • Member

  • 2,049 posts
  • Joined: March 05

Posted 12 May 2016 - 01:16

Jeez...how about use the whole sentence?

In Q1, we reached a new quarterly production record of 15,510 vehicles, up 10% from Q4. Q1 Model S production of 12,851 vehicles met plan, but Model X production of 2,659 vehicles was insufficient to meet our projected level of deliveries

 

What I understand from their previous releases is that there are quality issues with the rear seats. In an effort to solve it, they're bringing it in-house. Good on them.  Oh, and you forgot this:

 

 

Q1 Model S net orders rose 45% compared to a year ago, and grew at a faster pace than last quarter. The more rapid pace of growth was driven by increased order growth in North America and Europe, and a more than 160% increase in orders from Asia compared to a year ago. Model S continues to be the market share leader in North America and Europe among all comparably priced four-door sedans.

 

Emphasis mine.
 



#137 Canuck

Canuck
  • Member

  • 2,049 posts
  • Joined: March 05

Posted 12 May 2016 - 01:28

Of course, none of these things guarantee success for the company - that's certainly true. However the doom being rained down by the haters paints a vastly different picture than reality. Yes they're losing money but just a couple of years ago we'd have been left with just Ford as the only American car company if the government hadn't stepped in. And in truth, the old GM is gone and a new company wears its clothes (you may remember them escaping the wrongful death lawsuits for the faulty ignition keys as a result of that change). These guys are deadly serious about their business and business is getting better every day.  Oh, and their sister company just landed a rocket on a robot floating barge. Again.



#138 bigleagueslider

bigleagueslider
  • Member

  • 1,233 posts
  • Joined: March 11

Posted 15 May 2016 - 05:52

In reality, there is no such thing as an "American" car company any more. Ford produces many of the vehicles it sells in the US in Mexico and Canada. Honda, BMW and Toyota produce large numbers of vehicles in the US for both the US and global markets. Honda and Toyota stock shares are traded on the NYSE. TSLA's Fremont plant used to belong to GM and Toyota.

 

As for the US federal government's financial bailout of GM, contrary to claims that GM repaid all of its debts, federal taxpayers ended up losing almost $28B in the deal. As for TSLA, here's an LA Times article from last year that lists how many $billions taxpayers have given the company. I'm no TSLA hater. But I also have no illusion that TSLA is any different from other auto OEMs.



#139 gruntguru

gruntguru
  • Member

  • 6,603 posts
  • Joined: January 09

Posted 15 May 2016 - 08:44

If they were no different, they would be offering the same products.

Advertisement

#140 Canuck

Canuck
  • Member

  • 2,049 posts
  • Joined: March 05

Posted 15 May 2016 - 15:25

If the corporate headquarters is in the US controlling the purse strings, it's an American company.The products might be made elsewhere but that's a whole other political argument.

The largest difference between Tesla and the rest is Tesla's continuing commitment to making their technology open-source. That undermines my "Tesla owns the expertise" argument of course.

#141 bigleagueslider

bigleagueslider
  • Member

  • 1,233 posts
  • Joined: March 11

Posted 17 May 2016 - 05:08

If they were no different, they would be offering the same products.

That's not what I said. TSLA is a publicly owned corporation that manufactures and sells cars just like numerous other publicly owned automotive corporations around the world. As a publicly owned corporation, their management has a fiduciary obligation to act in the best interest of shareholders. And this means doing as much as possible, within the scope of the law, to maximize shareholder value. To TSLA's credit, this is what they have done by taking full advantage of available tax credits, taxpayer subsidies, and use of government owned properties. In this respect TSLA is no different than GM.

 

Eventually, if TSLA cannot produce a profit from manufacturing/selling cars, shareholders will demand the company pursue some other business that will generate a profit. I think this would most likely be as a supplier of batteries/motors/controls to other OEMs.

 

APPL is a good example of what public corporations with a US headquarters can do to minimize their income tax liabilities. Much of APPL's $billions of annual profit from outside the US is assigned to wholly owned subsidiaries in countries like Ireland where taxes are minimal or non-existent. I'm sure TSLA will take similar actions if they start generating significant profits from outside the US.



#142 gruntguru

gruntguru
  • Member

  • 6,603 posts
  • Joined: January 09

Posted 18 May 2016 - 03:53

 

That's not what I said.

 

Here's what you said.

 

 

But I also have no illusion that TSLA is any different from other auto OEMs.

 

 . . and I am saying - if you compare their product mix, Tesla is VERY different from all other auto OEMs (who all bear far more similarity to each other than to Tesla.)



#143 bigleagueslider

bigleagueslider
  • Member

  • 1,233 posts
  • Joined: March 11

Posted 19 May 2016 - 06:56

So TSLA's current availability of just one large sedan constitutes a "product mix"? Of course you can wait in line for a couple months to take delivery of an upcoming leased model X for the modest sum of $1261/month plus a $4456 down payment. That is enough to buy a nice house in most places of the US. The only auto OEM's that I can think of that have an average vehicle sales price of over $70K are Ferrari, Lamborghini, Rolls-Royce, Bugatti, Aston-Martin or Bentley. But unlike TSLA, most of these companies manage to produce a profit.



#144 Canuck

Canuck
  • Member

  • 2,049 posts
  • Joined: March 05

Posted 19 May 2016 - 12:53

I don't live in the US however a down payment of $4500 and $1260 monthly payments won't buy you a house in any major city in Canada. Of the OEMS you listed, only Ferrari it seems to me hasn't been sold or shuttered as a money-losing venture at least once.

#145 J. Edlund

J. Edlund
  • Member

  • 1,323 posts
  • Joined: September 03

Posted 21 May 2016 - 23:48

Aerodynamics and aesthetics apart its clear that even with ICE PUs there is a massive spread in shapes.  Vehicles like the Toyota Previa with the engine underneath the cabin are able to push the driver forward so the legs are ahead of the front axle as do all vans and trucks whilst maintaining an effective crumple zone so this isn't the reason the Tesla is the shape it is. If tiny cars such as the Smart or iQ whose entire length is probably not much longer than the bonnet on the Tesla S can have effective crumple zones there is no reason Tesla can reduce the length of the bonnet considerably or do away with it.

 

Tesla have been deliberately conservative with the shape as have Nissan, BMW etc (although the garnishing on BMW's electrics is eyecatching) because customer expectations are of a car designed with an ICE in mind.  Current expensive ICE saloons have a long engine bay to fit in large capacity ICEs therefore the Tesla is the shape it is to fulfil our visual expectations of a car in that price range.

It is little different to the first cars looking like horse drawn carriages with the horse removed and replaced with the petrol engine.  It took about 30 years before cars shook off their horse drawn visual heritage and started to look as if they had been designed purely for petrol propulsion.  I would have expected that with electrics the electric car makers would be distinctly braver and lead customer expectations rather than following it.

 

How far forward the cabin can be pushed isn't really limited by the engine but by the space required for the front wheels.

 

Many cars with short bonnets doesn't actually have the cabin pushed forward that much, rather it's the long tilting windshield that makes it appear that way. With trucks and vans the cabin is typically placed more above the front wheels, and small cars typically get away with a shorter bonnet due to their small wheels. Also, with a shorter front the crumple zone will suffer, which might not be that much of an issue on a truck but it will be for a car.



#146 Greg Locock

Greg Locock
  • Member

  • 5,550 posts
  • Joined: March 03

Posted 22 May 2016 - 00:35

All the space in front of the engine (assuming front engine) is wasted so far as crumple zone is concerned, if you are trying to eyeball crash results. The real passenger protection bit happens between the front wheels and the A pillar. All the bit in front of the engine does is decelerate the engine. (Very roughly)



#147 RogerGraham

RogerGraham
  • Member

  • 183 posts
  • Joined: October 12

Posted 22 May 2016 - 09:51

All the bit in front of the engine does is decelerate the engine. (Very roughly)

 

Greg, why is that space not used to extend crumple zone?



#148 Greg Locock

Greg Locock
  • Member

  • 5,550 posts
  • Joined: March 03

Posted 22 May 2016 - 23:28

Because it is 'wasted' just trying to decelerate the engine. Ideally you'd put the engine right at the front so it was the first thing to hit, and all the length between the block and the firewall could be used to decelerate the cabin.

 

This is a vast oversimplification, there again my limited exposure to crash was back before cartoon engineering, and oversimplifications were de rigeur then, as we had nothing better. Nowadays they can even calibrate the airbag sensors in the crash cae models pretty reliably. Which is pretty wow in my opinion.



#149 gruntguru

gruntguru
  • Member

  • 6,603 posts
  • Joined: January 09

Posted 23 May 2016 - 05:13

I am surprised that the zone ahead of the engine isn't used. It could be designed to crumple at a rate such that it was fully collapsed at the same time as the zone behind the engine. There are two drawbacks:

 

1. The design would only function as above at one particular speed.

2. The zone behind the engine would always be damaged - even in lower-speed collisions. (because the front zone would need to be stronger than the rear)



#150 Greg Locock

Greg Locock
  • Member

  • 5,550 posts
  • Joined: March 03

Posted 23 May 2016 - 07:45

Squiggle down a quick model of two constant force elements in series, and 2 masses. You want to minimise the acceleration of the second mass, and you don't really care what the first one gets up to.