|
One of the more common misconceptions about the Tesla Roadster is that it is an electrified Lotus Elise. This has been an interesting problem to deal with because the Tesla is vastly different from an Elise and it is important that people are aware of this. In fact, we recently counted how many parts the two cars shared and the total number was under 7% by parts count. If you were to analyze it by parts value, the number would be even smaller.
So you could say that the Tesla is similar to a Lotus Elise, except it has a totally different drivetrain , body panels, aluminum tub, rear sub-frame, brakes, ABS system, HVAC and rear suspension. The Tesla also neglects to carry over the gas tank, emissions equipment and exhaust. If you were to try to convert an Elise to a Tesla and started throwing away parts that aren’t carried over what you would basically be left with a windshield, dashboard (complete with airbags!), front wishbones and a removable soft top.
For comparison, Lamborghini cars share upwards of ten percent of their parts content with Audi cars. I can only guess what the number is between Ford cars and their high end Aston Martin and Jaguar brands.
At the same time, the Elise is a great car in its own right for what it was built to do. Several engineering breakthroughs that Lotus first implemented in the Elise, in particular the use of aluminum extrusions in the chassis that are bonded (as opposed to welded), have since been adopted by several carmakers and brands, including Aston Martin and Jaguar (note: I am not aware of any formal relationship between Lotus and those two automakers.) It was the fact that this approach yields a lightweight, rigid chassis and that the up-front tooling costs of extrusions are significantly cheaper than stampings that led Tesla to connect with Lotus about adopting a similar approach for the Roadster.
Early in Tesla’s history, after the company had focused on developing core battery technology, the time came to think about how to approach building a fully integrated EV car. As a startup, there were potential advantages to identifying an existing platform that had already been tested for US safety regulations and which could donate most non-EV parts. As with most things, however, the devil is in the details.
For starters, placing a 1,000 pound battery in the midsection of the car changes everything about the behavior of the structures that were originally engineered for the ICE powered Elise. In order to accommodate the added weight of the battery pack, the aluminum tub chassis had to be redesigned to a Tesla specification, increasing strength and using the battery pack as a stressed member to increase rigidity. Since we had decided to redesign the chassis, we also chose to redesign the side rails so that they would sit a few inches lower than those in the Elise, greatly improving ingress and egress. The chassis is produced for Tesla and does not start its life as an Elise chassis.
To accommodate the battery pack, motor and transmission, Tesla designed a new rear subframe. In order to handle the increased weight in the rear, new rear wishbones were designed. An added effect of the new rear subframe and suspension was a wheelbase about 2 inches longer than the Elise. The added weight, longer wheelbase, and desire for a different type of driving feel for our customer required a redesign of the suspension to achieve our ride and handling goals.
A challenging area of development for an EV that is not always obvious to the average person is the 12V accessories (fans, headlights, AC, heaters, etc.) All of these things have evolved over the last 100 years to run off the internal combustion engine. In an EV where there is no ICE and the main battery is running at about 400 volts, sourcing, designing and integrating these systems is no small feat. GM recently told of unforeseen problems they ran into in the development of the Volt related to 12V accessories that they say has driven the likely cost of the car up $5K to $35,000. Pretty much every car on the market uses a heat exchanger to transfer heat from engine coolant to generate cabin heat. That’s why the car has to warm up before it blows hot air. Every car on the market uses a belt driven compressor for the air conditioning. Every gas car also uses a belt driven alternator to generate 12V DC to run all of the other accessories. None of these things apply for the Tesla Roadster or any other EV, so they need to be designed specially for the car. I also left out power brakes, which normally rely on the vacuum from an ICE to generate boost (on an EV you need an electrically driven vacuum pump.)
All along, Tesla was developing its own signature styling for the Roadster. Once completed, every single panel on the Roadster was unique. The only exterior parts that are carryover are the rear-view mirrors, which Tesla carried over to avoid expensive development and safety testing costs. The headlights and taillights were designed to be unique to Tesla as well because they are so important to the character of the car.
As for materials: body panels (except for the bumpers) are made entirely of carbon fiber to minimize weight. By way of comparison, the next cheapest car that uses carbon fiber for body panels is the Mercedes McLaren SLR, which will set you back a cool $500,000.
So what remains as carryover from Lotus? The most noticeable pieces are the windshield and the dashboard, including the steering wheel. The fact that these pieces are so visible to the driver, passenger or gawker might partially explain the reason why people sometimes think the cars are closer cousins than they are. The reason we carried over these parts of the car was to avoid the onerous development and safety costs associated with passenger safety and airbag testing of a new design. Lotus had already successfully designed and tested the interior passenger compartment with the Elise and carrying it over made financial sense.
That concludes part 2 of the Mythbusters series. I’d love to hear your thoughts on other myths to address in future installments.
Thanks for the information; I seem to recall the same issue generating discussion on your most recent conference call. So, are there plans to upgrade interior electronics to run on a standard power source that makes more sense to an EV? I realize that this must be super long-term, once the 400-V EV is nearing dominant design status.
In the interest of heading off some possible myths. There are many current vehicles sold which do not have belt driven AC compressors or even alternators. The Toyota/Lexus hybrids have electrically driven AC compressors, water pumps etc. At least some of them do not have an alternator, but instead use a DC/DC converter for 12 volt power.
All things considered, it’s not a terrible thing to be compared to. I have driven the Lotus and it has left a favorable impression. Not to mention that one would be hard-pressed to find anything bad associated with the Lotus brand…
The bottom line is, nobody can dispute that the Tesla is a unique feat of engineering in its own right.
Garret
Darryl,
Great post. Having developed many iterations of existing product lines, I know how different the challenges are between starting from scratch and upgrading an existing system.
With an existing system, you have a complete parts list with qualified vendors, so you can go through the configuration, line out what you no longer need, while making a list of everything that needs to be developed to replace what you’ve lined out. Some new things require small changes by existing vendors, while others require new design / specification and new source qualification / selection. While, in spite of your best efforts, you always seem to end up replacing the vast majority of what came before, having that previous configuration gives you a great baseline against which to plan your new design.
With an entirely new product, it seems (to me) to be infinitely more difficult, because every member of the design team has their own vision for the new product. Creating the definition of this new product is far more about corralling the disparate visions, rather than actually designing and building. With a blank piece of paper, you have no reference to ensure that you haven’t left anything out, nor any gauge to measure any improvement to what’s in the market. You start from scratch qualifying vendors and costing you configuration, slowly getting your arms around the beast. It is so difficult to determine when and whether you are finished.
Thank God you started with a production baseline to achieve your current vehicle. The Whitestar will be, for the most part, a very similar drivetrain, with established sources, and you need only re-skin it - I know, I just said a mouthful, but you understand the power of leveraging what’s already been done.
Fortunately, gasoline hybrid cars have made electrically driven accessories much more common. For example, starting with the 2005 model year Toyota Prius cars use electric A/C compressors.
Speaking of development costs, GM spent around US $500 million on R&D for the EV1 platform in . Tesla Motors has so far raised US $145 million to date (including the February 2008 round). Presumably then Tesla Motors saved a great deal of R&D by using with Lotus’ technology.
Tesla Motors don`t have to develop all things
here you can find all you need
DC/DC Converter
Waterpump
Vacuumpump
EV Heater
electric A/C Compressor
at
metricmind.com
brusa.biz
Interesting post Darryl. I entirely agree with you that the Tesla Roadster is not a converted Lotus Elise. That would be a very inferior car and to call it that would be insulting to all you guys (and gals….sorry!) who have worked so hard to redesign and respecify everything on the car. I think you’ve done a great job, by the way. That said it’s still ‘based on’ the Elise. You started from that vehicle and if you found a Lotus engineer who had been in a coma for the last 5 years and knew nothing of Tesla he would only have to look at the car for a few minutes before he would start recognising stuff. If he drove the car I’m sure he would recognise the feel of it even though it is clearly a much heavier car with some different characteristics. Anyway, this is just semantics. It doesn’t really matter. Your car is a great achievement and something you can all be incredibly proud of. The fact that it is ‘based on’ one of the greatest handling cars ever designed is a real plus for the whole project. You’ve now made it look better and go better and do all of that while using much less fuel of any kind and creating zero CO2 at the point of use. At the same time you’ve created the first ‘proper car’ that is also an EV and pushed GM into the Volt programme, which will have a great impact on total electric mileage. It’s hard to think of another company that has achieved so much so quickly, but I have to tell you that I still think of it as Martin’s little company. It was his idea after all. Roll on the Whitestar….I can’t wait to see it.
Thank you for listening to my comment from a few days ago, and BIG THANK YOU for posting this blog.
This just proves my sneaking suspicion: Tesla is an awesome, responsive company.
-Max
:) You should put photo of elise and tesla
And no doubt ICE car is very different from EV car 
Your comments about dealing with 12 volt accessories brought to mind an electric car built around 1980 by the University of Arizona’s Electrical Engineering department. They took a very simple approach, they retained the 12 volt battery separate from the main battery pack. People would hookup the main changer and forget to charge the 12 battery. Since all of the control systems ran off of the 12 volt system, on several occasions, the car required jump-starts from a ICE.
They had a DC-DC converter, but that also required 12 volts to start!
David, the extra 12v battery is pretty common in homebrew EV’s. Mostly I think this is because we tend to use much lower performance batteries and/or DC/DC converters than what I imagine Tesla using. For instance, in my truck (converted ‘84 Chevy S-10) the DC/DC will cut out if the input voltage falls below about 100v. It’s expecting 120, and my pack is a nominal 144, so usually this isn’t an issue. But when I had a couple of (damaged) batteries taken out of the series, pushing the amps pedal too hard would cause the headlights to go out. Not so fun on a dark road. I would also lose my tunes, vacuum pump for power brakes, heat, and windshield wipers. This all became worse (that is, happened at lower acceleration) as the pack depleted. At the time I totally intended to add a 12v battery to the system…but once I replaced the damaged batteries the problem went away, and I’m lazy. Anyway, I expect people who have DC/DC units closer to their nominal voltage, or with smaller working ranges, consider this more necessary. In Tesla’s case, the multitude of Li batteries (instead of my few clunky lead floodies) probably leads to a lot less voltage sag, and I’m quite sure they have better ways of cleaning up the juice than I do. So I figure they probably have a much better solution going already.
BTW, that DC/DC converter sure sounds weird…why would it need an input at the output voltage? That’s just silly.
Blog: “Every car on the market uses a belt driven compressor for the air conditioning.”
Not Lexus/Toyota hybrids…
www.greenhybrid.com/discuss/f31/considering-highlander-hy-questions-about-c-6460/
Blog:”Every gas car also uses a belt driven alternator to generate 12V DC to run all of the other accessories.”
Again, not true on the Highlander, Lexus 400h and some other Hybrids:
www.greenhybrid.com/discuss/f31/12v-battery-question-16895/
Blog:”None of these things apply for the Tesla Roadster or any other EV”
Should we start referring to the Highlander and Prius as range-extended EVs now?!
Blog:”GM recently told of unforeseen problems they ran into in the development of the Volt related to 12V accessories ”
It seems lame of GM to say that they suddenly have a problem with electric powered accessories. They had them in the EV1, and their fuel cell prototypes already.
Can’t they just pick from their own parts bin?
media.gm.com/us/gm/en/news/events/autoshows/08chicago/brands/gmc080203/index.html
“Electrically driven 300-volt air conditioning compressor”
“Electrically driven 42-volt variable-assist power steering”
good job i’m impressed being a regular american middle class consumer. you’ve conquered mileage issues and charging times now your next problem. make it affordable to the middle class that really needs it to commute i think that is your next step and also making a passenger one. gas prices is putting a stranglehold on our economy if i seen an affordable one available to me in texas i’d buy it in a heartbeat. your vehicle is the beggining solution to our oil dependancy and outrageous gas prices, even if gas does go down it still cant compete with 1 cent per mile. your biggest challenge i see is affordability to the average consumer; availability and localized service centers.
Yeah, TEG, I agree…GM blaming the accessories for the Volt’s price increase was total and complete salmon (tastier than halibut, but still fishy). They already knew exactly how much those were going to cost. More likely they knew the car would cost more when they brought out the concept but shot low to get more ooohs and ahs at the show. Now…where are those folks who when the interim Roadster tranny was announced said “GM could never get away with breaking promises like this!” and the like? To be clear, GM is not going to install the extra five grand in the early-sold Volts when it’s ready.
Thanks Darryl. Excellent post.
As for future Mythbuster topics; having failed with airbags, I wonder if the opponents of EVs may try to whip up panic in regards to Electromagnetic Fields generated by power electronic switching systems. I know that the PEM has gone digital recently , so this might be an appropriate pre-emptive blog topic.
I am sorry to hear so many parts are unique. Good luck finding parts 10 years from now.
Not 100% electric but a step in the right direction.
www.cnn.com/2008/TECH/03/04/GM.hybrid.ap/index.html
Peter J Hedge
Victoria, BC
David–
I’m sorry, what parts were you referring to that would need to be replaced 10 years from now?
Engine parts?
Tires?
Batteries?
I’m to understand that all the major parts (other than body panels) that might require replacement are pretty standard across the Tesla brand. Okay, maybe the “Tesla” logo sticker will fade. I know BMW charged me almost $50 to replace the front left logo on my Z3 when it faded.
Other than those items, if you don’t wreck the vehicle, I’m guessing maintenance and parts availability isn’t too big a problem–after all, the car is electric, not gasoline-driven.
Yes, David, you won’t be able to find spark plugs, air filters, oil filters, oil pumps, starters, alternators, carburettors, fuel injectors, fuel pumps, catalytic converters, and a whole lot of other parts that all need servicing on an typical ICE car, because this car doesn’t need any of those.
Mechanics have good reason to not like this car much.
How do we find out more informaiton about local Tesla dealers/showrooms?
I have been looking for websites for the dealers in NYC, but can’t find anthing. Are you going to set something up like www.teslanyc.com or anything to make it easy?
Can’t wait to check these out in person… still dreaming about owning one someday, but these are inspiring me to work toward that!
Nice to see a Car like the TESLA in the US.
What about Europe? Is there any consideration or is TESLA-Motors going to leave the market to general Players.
I actually believe that the general Players in Europe will have an acceptable design in 50 Years.
However.
Your production Plant is in England. What stops you from supplying?
homologation requirements (re-engineering the car to meet various European standards) will take some effort. Expect to see us expand into parts of Europe beginning in 2009 or 2010. -ed.
Uh-oh, here comes GE, positioning themselves to become a major electric automotive giant:
www.reuters.com/article/innovationNews/idUSN0452745220080305
They’ve investing in both Think! and A123 - lining up their ducks.
Sweet! I’m sorta waiting patiently for when P2 is announced as having arrived
How about addressing some of the concerns raised in this news article stating that Plug-in cars could actually increase air pollution for those of us who do no intend to invest in PV until the technology becomes slightly more affordable over the next few years. A few excerpts below along with the link to the full article.
“The expected introduction of plug-in hybrid electric vehicles could cut U.S. gasoline use but could increase deadly air pollution in some areas, two reports say.”
“The Minnesota study found that use of PHEVs would lower most emissions compared with other vehicles, but that resulting SO2 emissions would be more than double those from gasoline vehicles and about three or four times greater than from driving a regular hybrid. Exactly how much depends on how far the PHEV can run on battery power alone. ”
“The Minnesota study also found that PHEVs would emit more carbon dioxide (CO2) than driving a conventional hybrid. CO2 is a greenhouse gas thought to contribute to global warming. ”
“The NRDC calculus shows that a plug-in charged from a power plant burning the dirtiest type of coal still has an overall pollution level less than a conventional gasoline car. But it would produce 11% more greenhouse gas emissions than a regular, non-plug-in hybrid, according to Luke Tonachel, vehicles analyst at the NRDC and co-author of the group’s report on plug-ins. The report was produced jointly with the non-profit Electric Power Research Institute.”
Full article on the link below.
www.usatoday.com/money/autos/environment/2008-02-25-plug-in-hybrids-pollution_N.htm
I need an all electric commute vehicle now. I prefer a sedan. What can I expect from Tesla and when?
I’m very interested in the Tesla Roadster, but am not able to drive a sportscar (it looks great, though). I keep hearing about a Tesla Sedan. Is the Tesla Sedan a myth or a real future project?
Thank you.
I really want a Tesla, but we understand Montana has a law saying electric cars can only travel a maximum of 35 MPH! How does a person get around this, or are you working on this problem already?
The problem of plug-in cars ultimately drawing increased electric power which could result in greater pollution from coal-fired generating plants needs some attention. I would suggest that the ultimate answer is in increased use of solar generation of power. Thus solar power feeds all-electric plug-in automobiles which in turn reduces atmospheric pollution to zero!
Mark,
Boy, that’s an alarmist article. One can get a decent idea of the author’s knowledge by the fact that he says that the Volt isn’t a hybrid, because the engine doesn’t directly drive the wheels (I guess that means it won’t hurt the environment like those dangerous plug-in hybrids). The study seems to only have found that recharging using the very dirtiest power plants would be a problem, but the author sure made it sound like plug-in hybrids are more dangerous than DDT and PCBs combined. Look out! They’re coming!
The solution isn’t to avoid plug-in hybrids, the solution is to clean up the dirtiest power plants.
Keith
when is there going to be a car with the same mileage for around 20 grand . the rich ones that can afford 100 k are not going to buy them after the first edition is gone and to have only a few thousand of them on the road is not going to help the enviorment. there is a need for the average person to have one of these cars and if you are a responsable as you say you are you should make one otherwise you are just blowing smoke you really havent accomplished anything. and if you do make one i will plug into my solar system to refuel
that there is no place to service the vehicles when they break down and they break down frequently
Hey Darryl, you wanna bust a myth and help sell some Teslas at the same time? Take a look at that dumb article from USA Today and get to work on refuting their claims. You wanted suggestions for myths to bust, well this has to be the biggest myth of all surely. Regular gasoline cars are less polluting than EVs and Hybrids. I don’t believe that for a second and I’m sure you don’t, but that article is out there and you can bet it will still be quoted years from now so it needs to be refuted.
Even if it was a Lotus it wouldn’t bother me…The Lotus was on my short list when I bought my FX 35. Family comes first, but I’m still very happy with my Infiniti. I’m very excited to see what the new sedan looks like. Are you still planing the plant in Albuquerque? That’s where I’m living at the moment, and I’d love to buy the first one off the line!
Geoff Tuttle
When Lotus designed the Series 2 Elise platform it was possible to adapt it into a number of different configurations of roughly the same size - Elise, Exige, GM Speedster, Europa, and the Tesla
Lotus at roughly the same time was designing the chassis for the Aston Vanquish. The XJ Jaguar doesn’t use the same technology.
The next step forward was to design a platform which could underpin a wider variety of cars - they had significant input on the DB9/Vantage/Rapide platform. Project Eagle/new Esprit will share a similar set up, possibly with a saloon to follow.
No, the Tesla isn’t an Elise. But the best sportscar chassis in the world isn’t a bad place to start
#Jo Anne Herem wrote on March 5th, 2008 at 1:43 pm
#I really want a Tesla, but we understand Montana has a law saying electric cars can only travel a maximum of 35 MPH!
#How does a person get around this, or are you working on this problem already?
This sounds like a misreading of the legislation. In 2007, Montana apparently upped the speed limit for “Neighborhood Electric Vehicles” (NEVs) to 35MPH from 25MPH. NEVs don’t have the same strict safety requirements that standard cars, like the Roadster, have to meet. The Roadster passed the Federal safety standards, and is legal to drive in all fifty states, as I understand it.
You might check out this news item for more:
www.greencarcongress.com/2007/04/montana_enacts_.html
Blog: “I’d love to hear your thoughts on other myths to address in future installments.”
Has the myth of Li-Ion fires in crashes been disproved enough already now?
There was a myth that tall people (e.g.: 6′4″) can’t fit in a Tesla that I think have been disproved.
How about short people (e.g.: 5′4″)?
People have all sorts of random ideas of how long it takes to charge the roadster using different charge connectors.
(Supposedly showing that a 3.5 hour full charge is not possible)
How long does it take to fully recharge an empty roadster using a 120v 12amp circuit?
Does the ambient temperature affect charge time?
There has been speculation about rebates and tax credits for EVs. I think some things were in the works that may or may not be available.
Also, the Roadster price initially was supposed to be $100K for signature 100 cars, then dropping lower for later models. It seems the price is going up rather than down. Perhaps you could explain this. I know some is due to exchange rate issues with Euros and Pounds turning out to cost more $ now.
some are targeting well over 1,00,000 units per year for their Hot sedan by 2015 can Canada get them by 2011?
Why aren’t they in Canada yet?
Is the Tesla Electric Plane still in testing?
Environmental Solutions Development Manager
Boomrides.com
Doesn’t the Audi A8 also use carbon fibre body panels?
No - it is all aluminum. -ed.
Hi from Barcelona (Spain) in Europe!
Congratulations for this interesting and wonderfull car!
…But…¿Why I can`t buy and drive a Tesla Car in Europe? Is this possible?
I`ll like speak with my goverment in Spain, any Organitzacion here in Spain for this dream will be possible….
Sorry for my English….
Thank you!
Blog: “the next cheapest car that uses carbon fiber for body panels is the Mercedes McLaren SLR, which will set you back a cool $500,000.”
There has been some carbon fiber on various Corvette models for a while now:
www.compositesworld.com/hpc/issues/2003/July/146
www.compositesworld.com/hpc/issues/2005/November/1087
www.sea6.com/
“* Wider, carbon-fiber front fenders”
“* Carbon-fiber hood”
“* Carbon-fiber roof panel, roof bow, front fascia splitter and rocker moldings with clear-coated, exposed carbon-fiber weave”
Is the “Mythbusters” blog series meant to perpetuate myths or “bust” them?
I meant that uses all carbon fiber body panels…geez…tough crowd. -darryl
I agree with those who say the “long tailpipe” should be addressed in this series. I’m of course aware that it’s in the FAQ, but that’s a pretty short once-over, and doesn’t come with numbers. It might help some to flesh it out…and obviously there are lots of folks who don’t get around to reading the site. In any case, it’s definitely the biggest misconception around with regard to EV’s in general.
Another possible myth I’ve heard (though somewhat less often) is that it takes more oil to build a Roadster than it would consume in its normal driving life were it gas powered. Usually people who say this claim that this is true of all cars, which is definitely wrong; I went and found a lifecycle analysis that found something like 85% of the energy that goes into a typical vehicle happens in the driving cycle. And of course the other 15% happens at the factory, where it’s not oil-based. That just leaves the plastics as the oil consumption. But the Roadster is a bit trickier question, because of all that carbon fiber (which I’ve been led to believe is made with oil?). So I guess I’ll posit the question straight up: How much oil goes into building a Tesla Roadster? Of course, even if it’s a lot the emissions of said oil wouldn’t be as problematic…the carbon goes into the panel, not the air, right? But still, a full lifecycle analysis of the vehicle would be awesome, and if that’s too much then maybe a simpler treatment of just what natural resources go in.
Also, it might be worth your while to address the maintenance concerns. In my opinion this needs more than just saying “it won’t break down.” I understand that it is inherently more reliable than an ICE vehicle, and that’s a good place to start…but you show me a machine that can’t break, and well, I’ll break it for you. It would be good to know what the gameplan is in the (however unlikely) event of something going wrong. Putting the car on a flatbed and sending it back to the factory might be palatable to the hundreds who spent $100k on a Roadster…but it’s less likely to be a workable solution for the thousands who will spend half that for a sedan, and unthinkable for the tens of thousands who spend a third of that on bluestar. Also, with all this fiber, what happens when someone wrecks? I don’t suppose those panels are at all repairable, so can my local body shop order up replacements from Tesla somehow? Maybe this isn’t as much of a “myth” to dispel as it is simply an area where a little detailed discussion is warranted. Maybe it should go in one of the other blogs.
Anyway, thanks for the post; looking forward to seeing more…
About the USA Today article:
I love it when a “study” draws a conclusion based on the lowest common denominator:
“recharged with power from the least-sophisticated coal plants”
Considering the wording, I’m going to guess all other forms - including more-sophisticated coal plants - are better for EV’s to charge off of.
Solution: Upgrade all the least-sophisticated coal plants.
Ah well… at least the article is good for a chuckle or three.
I would absolutely LOVE it if you could bust the myth that the Whitestar is going to be similar to the volt in the sense that it is an EV with a generator. We - or at least I - love the fact that Tesla is producing EVs and not getting into the “hybrid” market. Leaving out all of the symantics of what is Hybrid and what is not. In short I believe that if it has two systems it is Hybrid but I am sure others will differ in opinion. I know we will be seeing some details on the Whitestar soon but any idea how soon. ” 2ndQuarter of 2008″ is coming up VERY soon.
If we are talking Myths, here’s one for the petrol heads. Two years ago me and my then 17 year old son felt our hearts flip when we stumbled across this beautifully styled, tarmac polishing piece of automolbile fantasy and, seeing as we are keepers of the Earth type of consumers, that the Tesla was 100% electricity powered, got us counting the coins. But like all good fairytales and myths, we had to face up to the reality after the last flicker of the screen deminished to a single spot, we had to console ourselves with a couple of T shirts, mugs and key rings with Tesla branding! This dream is Not available in England but lets hope that the Tesla doesn’t exist as a myth in Europe for too long!
##TEG wrote on March 6th, 2008 at 9:06 am
##Blog: “the next cheapest car that uses carbon fiber for body panels is the Mercedes McLaren SLR, which will set you back a ##cool $500,000.”
##There has been some carbon fiber on various Corvette models for a while now:
Not for me to say really, but I think what they meant to say was that the next cheapest car, sold in the USA, that uses ONLY carbon fibre for its body panels is the Mercedes ….. Maybe then the statement would be true. Small words can be important when you are mythbusting.
Kevin Harney, unfortunately that’s not a myth. In a blog here: www.teslamotors.com/blog2/?p=54 Elon Musk mentions it:
“As was alluded to in the customer town hall meeting last week, Tesla will likely provide both pure electric and range extended electric drive options in the future. We refer to the latter as a REEV (Range Extended Electric Vehicle) to distinguish it from “hybrids,” which are really just gasoline engine cars with a small electric motor and tiny battery. The REEV battery in our scenario would fully cover the range needs for reasonable daily usage, but there would be an onboard generator for the occasional long trip.”
As much as I agree with you that pure BEV’s are the way to go, it seems clear at this point that there will be two models of Whitestar, and one of them will have some sort of gas-burner on board in a serial hybrid arrangement. There has been some talk that suggests the pure BEV model will come out a good deal sooner, and the lack of details on either one at least gives us some time to fantasize about fancier-than-otto-cycle gensets (say a turbine, or even a linear-combustion generator) so it’s not all terrible.
And TEG, it sounds like Andrew has the correct version there; it corresponds to what Elon said in the video of him crusing around in P1 at least. But yeah, semantics or not Darryl’s statement there isn’t quite right.
How much truth is there to the rumor that the Tesla Car company is a front in order to sell tee-shirts for $38.00?
drats…you found us out -ed.
A parallel hybrid REEV would be more efficient than a series hybrid REEV because, as J.B. Straubel explains:
“However, this [series parallel] approach suffers from the inherent problem that the energy is transformed from mechanical (at the IC shaft) into electrical, and then back to mechanical (at the EV motor.) The energy will in the best case go through the generator, EV motor controller, and EV motor. In the worst case it will also cycle in and out of the batteries. All of these conversions deal a serious blow to the best efficiency possible. For a typical EV system you will need between 1/2 and 2/3 of the IC horsepower to simply push the car as you will to generate enough electricity to drive it.”
# Andrew Kelsey wrote on March 6th, 2008 at 10:44 am
##Blog: “the next cheapest car that uses carbon fiber for body panels is the Mercedes McLaren SLR, which will set you back a ##cool $500,000.”
##There has been some carbon fiber on various Corvette models for a while now:
# Not for me to say really, but I think what they meant to say was that the next cheapest car, sold in the USA, that uses ONLY carbon fibre for its body panels is the Mercedes
Myth busting is all about avoiding situations where you assume people will know what you _meant_ to say…
Hunter,
While I prefer a BEV a REEV is acceptable. What I what to know is that the Whitestar will not be like the VOLT in the sense that it can only go like 50 miles on EV power before it needs to kick in the ICE. I am hoping for a range in the area of 200 miles and if it has a generator that I can use after that great. I will just never use it !!!! LOL. BTW Tesla should be aiming for 0-60 in 4.1 and a 1/4 mile in 12.2 for the Whitestar. I believe if I am not mistaken that will make it the fastest production sedan ever made. And, I believe that someone correct me if I am wrong
There is also the Myth that the Tesla Roadster is the fastest car in 30-70 acceleration bar none.
For instance see this:
ballyboughal.net/tag/tesla-roadster/
“it has a faster over taking acceleration speed (between 30-70 mph) than any other production car ”
What I think they meant to say is that it is the fastest in 30-70 of any car that Car & Driver tested in TOP GEAR in 2007.
Using top gear really handicaps manual transmission supercars geared for 150mph+ top speed.
Also, using only Car & Driver as the source narrows the competition further.
You really need to qualify that metric with these extra caveats:
Tested by Car & Driver, in 2007, all cars in top gear.
Tesla’s press release says:
www.teslamotors.com/media/press_room.php?id=825
“…the fastest 30 to 70 mph acceleration of any production car ever tested by Car & Driver magazine,…”
So the “in 2007″ and “in top gear” was left off…
Car and Driver already gets flack for their top gear only 30-70 testing:
forums.caranddriver.com/auto/board/message?board.id=10&thread.id=4077
I know, tough crowd, but fans want real, complete facts, not cherry picked, “oh we left off that detail” sorts of facts.
Mark, it’s true that parallel hybrids are potentially more efficient than series hybrids if you’re always driving on gas (that is, if you’re not plugging the car in). I seriously doubt it’s as dramatic as Straubel claims…looking at the generator and electric drivetrain efficiencies I’d say it’s more like you’re paying a 15% penalty or something like that. But the more important problem is that in the parallel configuration you have to run the engine nearly all the time. The electric motor doesn’t have enough power for around-town speeds, much less the highway. So you remove the ability to make a commute without ever turning on the ICE…it can’t really be used for an REEV, unless you make both drivetrains big/heavy enough to push the whole (now much heavier) car alone. Obviously if you can complete your drive entirely on electric power you are doing it vastly more efficiently than you would if you were running the ICE. Since the vast majority of people drive a relatively short distance every day, this makes the series-hybrid much more efficient overall for most people.
TEG: Yup that was obviously wrong and confusing. What they should have done is compared 30-70 times in the BEST gear for each of the cars. Normally the 30-70 test is to check the flexibility of the IC engine but for a fair comparison with the Tesla, for overtaking ability, the cars should be compared in the gear you would normally use. How many people will start their 30 - 70 overtaking in a 200 mph Ferrari in top gear? Not many I would think and in first or second gear most fast IC cars like a Ferrari will be likely to beat the Tesla at those speeds.
It just makes Tesla look bad if they perpetuate myths like this. Elon even did it himself in his night time drive with Scoble when he said the Tesla was quicker than his F1 from 30-70. I’m sure it isn’t if the F1 is in the correct gear for that speed. The car is good enough. They don’t need to exaggerate its qualities by asking a car that is geared for 240 mph, like the McLaren, to struggle at 30 mph in that same gear. Only a very bad driver would use the car like that.
Hunter, there’s yet another advantage to the Volt style series hybrid or REEV or E-REV, or whatever you wish to call it. Because the IC engine only has to meet the average power demand it can be much smaller than the equivalent IC engine in a normal car or in a parallel hybrid.
TEG said: Myth busting is all about avoiding situations where you assume people will know what you _meant_ to say…
TEG, I agree with you 100%. That was the point I was trying to make. We are a ‘tough crowd’ but they need to be much more careful with these kind of statements. The detail is important. I’m a fan of the Tesla but I’m not a ‘fanboy’. I don’t need exaggerated figures or phony comparisons to be impressed by the car.
The figures below are for the McLaren F1 and show 2.1 seconds for 30-70 through the gears which is pretty amazing when you consider that 1st gear only goes to 65mph so they have to change up just to get that last 5mph. Still a good deal faster than the Tesla, as you would expect for such an expensive and unique car with the pedigree that it has. The LM version revs to 7,800 so it would almost reach the 70 mph mark in first gear, which would no doubt give a time of under 2 seconds.
Standing 1/4 mile 11.1 secs @ 138 mph
Standing km 19.6 @ 177 mph
30-70 mph through the gears 2.1 secs
MAXIMUM SPEEDS
6th in excess of 230 mph
5th 180 mph @ 7500 rpm
4th 150 mph @ 7500 rpm
3rd 125 mph @ 7500 rpm
2nd 95 mph @ 7500 rpm
1st 65 mph @ 7500 rpm
In fairness to Tesla I suspect the Press Releases are written by non-technical people who don’t understand the importance of the caveats. That said, if it were my company I would insist on proof-reading every Press Release and stop the junk going out. Or get a PR firm that understands cars. One way or another they need to catch this kind of thing before too much damage is done.
Bust this myth: Tesla will never have a consumer vehicle travelling US roads! I read a few weeks ago that chairman Elon Musk would be getting his Tesla in about a week. Seems like that time frame has passed, and if he got it - I’m sure it would have been mentioned here. When are some Roadsters actually going to be put into use?
The key to a REEV is simplicity and efficiency. The drivetrain of a serial REEV is identical to that of a BEV - no transmission, one gear. The generator can be designed to run at one speed - full speed. That can lead to many efficiencies. And it doesn’t take anywhere near the ICE power of the traditional parallel hybrid.
For example, assume a roadster baseline, with a battery range of 200 miles. A quick search turned up a 10KW portable generator with a 20HP engine weighing 375 pounds. This could certainly be improved with optimization for this application. A reasonable rule of thumb for the roadster is 250 Wh/mile (50kWh/200 miles). So running the generator at full power would add 40 miles to the range for every hour it runs. But you might think., “I don’t want to drive at 40 mile/hour.”
If you start the generator shortly after beginning a long trip, it will greatly slow the rate of battery drain, and add 40 miles of range for every hour of driving. If you drive 50 MPH (to make the arithmetic easy), it would take 4 hours to normally drain the battery. At the end of 4 hours, you would be 200 miles down the road, and you’d still have 40*4=160 miles left in the “tank.” You would actually run “dry” at about 1000 miles, at which time you’d have to drop back to 40 MPH. If you stop for lunch along the way, the range is essentially infinite… on 20 HP… with roadster performance. Your mileage will vary - if you drive faster, efficiency goes down and chaging time decreases (at 70 MPH, all other things being equal, the range drops to 460 miles without stopping). In the first example, there’s a break-even point (infinite range) of 12.5kW. At 70 MPH average trip speed, the break-even is 17.5kW. It’s fun to play with the numbers. And it turns out that battery capacity is pretty important.
Of course, the key is to tell the car whether you are going on a long trip or a short trip, so the generator starts early on the long ones. It makes a generator in a trailer an intriguing concept.
Justin,
Elon got his car over a month ago and has been driving it since !!!! AND he has posted to that effect with his driving experiences AND a video.
# Justin Cole wrote on March 7th, 2008 at 8:19 am
## Bust this myth: Tesla will never have a consumer vehicle traveling US roads!
You must not have looked through the Tesla blogs carefully:
www.teslamotors.com/blog2/?p=56
P1 was delivered and has been driven quite a bit on public roads now.
1 down, 900+ to go (to satisfy current backorder demand)
# Andrew Kelsey wrote on March 7th, 2008 at 7:29 am
## … McLaren F1 show(s) 2.1 seconds for 30-70 through the gears which is pretty amazing when you consider that 1st gear only goes to 65mph
Yes, when Car and Driver tested the Corvette Z06 in 2005 they got a pathetic 23.5 seconds for 30-70 in top gear (which is an extreme overdrive gear for fuel economy).
When they were actually willing to use the shifter they got 0-70 in 4.5 seconds. Yes, 0-70 quicker than their published times for the Roadster doing 30-70 roll-on acceleration.
www.caranddriver.com/reviews/hot_lists/high_performance/muscle_cars/chevrolet_corvette_z06_road_test+page-4.html
I love the Roadster, and it is a very quick little car, but it isn’t the quickest / fastest vehicle ever.
It might win in some more nebulous statistics such as “most efficient supercar”, “quietest car for 4s 0-60″, and perhaps even “most fun”.
I still think it might even be the best looking car on the road, but that is a matter of opinion.
Bill B,
That is an intriguing concept. I like the idea that I can leave the generator off 99% of the time ( especially with a 200 mile BEV range) and if I am going on a long cross country trip I can turn it on and be able to AVERAGE 50 mph ( and I think that is really moving, eating in the car and peeing in a cup and no family [ most people that want a Sedan have a family] could travel that way) for say 10-12 hours. What size generator would be needed for that and how much of the DREADED gas would be needed to run it for 12 hours. Not that I would WANT to travel all day with zero stops but it would be POSSIBLE. And would probably still yield somewhere in the neighborhood of 100 MPG.
Kevin, 200 miles before the generator kicks in is pretty unrealistic. Since Whitestar is going to be bigger, heavier (even without lugging an ICE), and less aerodynamic than the Roadster, it would require a much larger battery pack to get that kind of range. A pack that size would be far too expensive to meet the sedan’s price targets. But more philosophically, since something like 90% or more drives happen down in that 50 mile or less range, that’s sort of a natural sweet spot…it just makes sense to shrink the battery down to that size to save weight and expense. Increasing the pack range gives you very little benefit: double your pack size (and weight, and cost) and you can now serve another 5% of driving. That’s not very cost effective, and it also lowers the efficiency of all the short drives. Anyway, I’d like to see it have a bit more range than the Volt and other REEV’s…makes sense for Tesla’s niche to say “longest EV range among plugins.” But I wouldn’t expect it to be dramatically higher. If you want a long electric range, go with the pure BEV version.
Bill,
Let’s look at the math again. The way I am reading it your numbers are flawed. But my math skills need something to be desired.
In 4 hours you would generate enough to go 160 miles which translates into like 3 more hours.
In 3 hours you would generate enough to go 120 miles which translates into like 2 more hours.
In 2 hours you would generate enough to go 80 miles which translates into like 1 more hour.
After that hour you would be reduced to the 40 MPH rate.
I get 12 hours and 640 miles… what am I missing ?
Hunter,
Agreed but I was using Bill’s numbers just for the example. But for most people that travel the AVERAGE of 50 miles daily they would need a range of closer to 80-100 miles to feel comfortable because nobody wants to drive on empty hoping they will get home. I for one drive a 150 mile trip quite often and would like to be able to do that and give up my ICE vehicle. Without that I can’t do it. Have to keep the old one too.
Hunter,
A sedan would have more space to hold a larger battery pack so that could improve things a bit. Plus a sedan would not gobble up the battery at the rate of the raodster right ? We would no be doing 0-60 in 4 seconds …. or 120 MPH !!! LOL
Kevin; Is “peeing in a cup” and “no family” connected in some way?
This is obviously where i’m going wrong with my teenage kids always asking for lifts.
So if we scale the battery down to say 100 miles. You would need a generator capable of making enough power to travel 50 MPH to be able to drive infinately. I would be able to do my 150 mile trip with no worries of running out of power AND i would do it on the amount of gas needed to run the generator for 1 hour. Would that be like 1-2 gallons or so ? That is still in the range of 100 MPG.
So how much does a typical V6 or V8 weigh? 1000 lbs? That is the same as a battery pack. Same engine compartment - different engine. What about Drive train ? Same ? and a second battery in that area beneath the car where drive train would have been. That would be like a 200 mile range. Is that so unreasonable ?!?!?!?!
Kevin,
It’s all in the fractions. In this example, “like 3 more hours” is actually 3.2 hours. It asymptotically approaches 996 miles. Here’s the start of the series…
Miles Time Energy Additional
(H) Produced Range (mi)
(kWh)
200 4.00 40.00 160.00
160 3.20 32.00 128.00
128 2.56 25.60 102.40
102 2.05 20.48 81.92
82 1.64 16.38 65.54
66 1.31 13.11 52.43
52 1.05 10.49 41.94
42 0.84 8.39 33.55
34 0.67 6.71 26.84
By this point, you’ve covered 866 miles driving nonstop for 17+ hours, and you still have 21 miles in the battery.
Again, there are several gross assumptions here, but the fundamenal point remains the same - the ICE doesn’t need to have any torque curve (runs at one speed), and only needs enough power to replace the AVERAGE energy consumed during a day - MINUS the initial charge, assuming that you can recharge overnight.. I think it makes for a great tradeoff vs. the traditional parallel hybrid given that the desired performance can be achieved with electric alone, which Tesla has demonstrated.
Thoughts on Fisker’s Karma REEV? 2+2 coupe, scheduled for Q4 ‘09, $80K, 50 mi. electric-only range from a li-ion pack, inline four ICE, solar roof (for the marketing pizzaz).
My thoughts are that it is a concept car at this point. I won’t be able to fully evaluate it until they build a working prototype, which they have said won’t be until late this year. The hardest part about EVs is the drivetrain and all the public specs for any concept car are not meaningful until the manufacturer gets specific about their technology. I wrote a blog about my first impressions on my Horseless Age blog at sirycars.blogspot.com/2008/01/fisker-automotive.html - darryl
Fuel efficiency for BillB’s table above came to 25.5 mpg (or 1321 Wh/mi) based on the specifications for the Honda EB11000 generator. While the EB11000 is only rated for 9500W continuous, it seemed close enough for a quick check.
Kevin, you’ve got a few problems in the above posts:
First off, you say, “for most people that travel the AVERAGE of 50 miles daily they would need a range of closer to 80-100 miles to feel comfortable because nobody wants to drive on empty hoping they will get home.” Did you forget there’s gas power to fall back on? They won’t be “hoping they get home” but rather calmly aware of the fact that in the unlikely event that they go past the electric range the car will just go the last few miles on petrol. (Also, concerning your frequent 150 mile trip…I do a 170 mile-per-direction trip a little less than weekly. That’s why I’ve still got my gasser, but it doesn’t stop me from driving my 40-mile-range EV the rest of the time. The “hybrid garage” is really a pretty good solution.) (Also, note that the “average” daily travel is much, much less than 50 miles. 50 miles is something like the 90th or 95th percentile. Does anybody have the real numbers here? I’d love to see the distribution curve…)
Next are your thoughts on the sedan’s battery pack. Yes, there will be somewhat more space available. However, that is irrelevant, because the space is not the limiting factor; expense and weight are far more important. You can’t build a $50k car with a $40k battery in it. At least not while maintaining some semblance of quality, much less luxury. Also, your assumption that the sedan will consume less battery power than the Roadster is mistaken. It is true that it won’t have the same acceleration…but that’s because it’s going to be way bigger and heavier. I’ve read that the motor in Whitestar will be bigger and more powerful than the one in the Roadster; that means that under full acceleration (whatever that ends up being) it will draw more from the battery. Furthermore, the simple fact that Whitestar will be heavier and less aerodynamic means that in any given driving scenario it will use more power. This gets worse the more weight that’s one board, so increasing the pack size actually increases the amount drawn for any given drive. So in other words, it is very clear that it’s going to take more energy to move Whitestar around than it does the Roadster.
As for your comparison of engine and battery weight, I’m not sure where you’re going there. I suppose there might be some few cars that carry 1000lb engines around, but that sounds atypical to me. More importantly, you’re acting like the Whitestar can get away with having the same weight as a regular car and still get Roadster-class Whr/mile, and that’s just not right. The Roadster gets where it’s going without using a ton of energy because incredible time and expense were devoted to making it extremely light and aerodynamic. TEG says (and he’s quite reliable) that it takes about 250Whr/mile to move the Roadster. Put that same pack in a “normal” car that weighs half-again as much and isn’t nearly so windtunnel-friendly, and you won’t get near the same range. And that doesn’t even consider that in the REEV you have to haul the ICE (and fuel!) around. Sure, I would count on them using the lightest thing they can get away with (what do you guys think? Say 150lbs for the generation unit, not counting the gas?) but it’s still not trivial. And then you build a four-door car with sedan styling that’s not completely carbon-fiber, and it ends up taking a lot more energy to move it. I don’t know exactly how much, but I’d be surprised if it was less than say 350Whr/mile. So if you want this thing to get 200 miles on the battery, you’re talking about a 70KWhr pack. Actually probably more like 80 once you figure in the drivetrain efficiency (or is that already in the Whr/mile number?) I simply don’t think you can build a pack that size cheaply enough to put into a $50k sedan, particularly if you have to spend money on all the fancy ICE bits and the “luxury” aspect. Sorry, but it’s just not going to happen.
Anyway, there’s still no reason why one of these (even assuming a 50mile EV-only range) couldn’t work for you as your only car. It just means you’ll still burn some gas when you make your long trips. I’m confident it’ll still burn much less than whatever you’re driving now, even on those long drives. And the rest of the time when you’re just driving around town it’ll be no contest. That’s what excites me about these things…my hybrid garage could be in just one car, and I’d still have more EV range than I’ve got now. That sounds really appealing to me.
TEG wrote on March 7th, 2008 at 10:05 am
# Justin Cole wrote on March 7th, 2008 at 8:19 am
## Bust this myth: Tesla will never have a consumer vehicle traveling US roads!
You must not have looked through the Tesla blogs carefully:
www.teslamotors.com/blog2/?p=56
P1 was delivered and has been driven quite a bit on public roads now.
1 down, 900+ to go (to satisfy current backorder demand)
Thanks for the link to Elon’s blog. Although I am sure I check the site less often than some, I know that I have checked it since the date listed for his post. Like I alluded to earlier, I thought that would have garnered website front page coverage. Anyways, great to here that P1 has been delivered. Now I can sit back and pray for everything to work out for Tesla, and in a few years (or more?) I can be happily driving my White Star or Blue Star sedan (or some other vehicle manufactured for us average income environmental enthusiasts).
The National Household Travel Survey 2001 has a bunch of data on American travel. Table A-17 in the Highlights of the 2001 National Household Travel Survey starts to answer the question (average trip is about 30 miles) but more distribution information is needed.
Commenting on Hunter’s assertion:
# “TEG says (and he’s quite reliable) that it takes about 250Whr/mile to move the Roadster.
# Put that same pack in a “normal” car that weighs half-again as much and isn’t nearly so
# windtunnel-friendly, and you won’t get near the same range. ”
I drive an eBox to work every day that fits that description (3000lbs, box shaped). Driving in a mildly conservative manner on hilly terrain with lots of stop and go gets me around 220 Whr/mi. If the route were flat I’d be at 175 WHr/mi.
# Hunter wrote on March 7th, 2008 at 4:23 pm
## TEG says (and he’s quite reliable) that it takes about 250Whr/mile to move the Roadster.
When did I say that?
Maybe you meant “BillB” ? :
# BillB wrote on March 7th, 2008 at 8:55 am
## A reasonable rule of thumb for the roadster is 250 Wh/mile
I don’t think I ever tried to state a figure for that, but I guess we could just do some math of 53kWh pack capacity / 221 mile (EPA) range estimate = ~240 Wh/mile.
TO be quite clear then. Tesla has pretty much achieved an amazing result with the Roadster. Why people have to debunk it or critize it makes no sense!! Building a full production car is difficult allready. Building a new tech. EV car and bringing into production is a HUGELY difficult task. But one thing I have realised, no matter what the FACTS are, people will always have opinions, some negative and some positive. I think this is human nature. Good luck with your production launch (GA??), I am sure the production and procurement teams are working non-stop!
Hello from Austria!
I am a proud owner of a Lotus Elise MK2. Sure the Tesla has many similarities to this wonderful car, and the people at Norwich are perfect for producing its chassis. Colin Chapman would be delighted. Now please, please make it available for the alpine roads in Europe!
By the way, if we cannot drive the car, can we buy shares?
Hunter,
Thanks for the well thought out post. Some of what you said I agree with and others I do not. First of all for me and probably 90% of the people on the east coast you are looking at a 20-30 mile commute in EACH direction. So 50 miles is simply out of the question. We would be using the ICE everyday. And though this is still better than using it ALL of the time it is still not desirable for me anyway. I want to be able to make my daily driving with NO GAS. Longer trips are acceptable to use it but daily is not to me.
As to your point on battery power and size. What I was trying to get at was if say there were 2 Roadster packs in the Whitestar would that be enough to produce a VERY reasonable range - say somewhere in the 100 -150 miles ? I did not know what a engine and drive train and all the unnecessary parts would amount to in weight but my point was I think it would be close to a pound for pound replacement in the same size vehicle. Would the preformance be enough to allow that? Sounds like the post from the owner of the ebox thinks that it would. And if I am not mistaken 2 Roadster packs is more than the 70 KWhr that you estimated. So am I really that far off ?!?!?!?!? I am not sure ….
What about an all-electric powered truck? I would envision something from Tesla that looked like a Lincoln Mark LT. I know that it would be incredibly heavy but trucks have a lot of space where extra battery packs could go. I think the plan of Tesla to start with the high end market and work down is absolutely brilliant, but there also is something to be said about the high profit margins with the more expensive cars. It could also make a statement by putting another trophy in the Tesla case of having the fastest truck, which I think the instant acceleration of an electric motor would provide. Does anyone know if electric motors are good for towing or are they just good for speed? And maybe this isn’t even possible with how expensive the batteries would be but I believe there are thousands of Americans who would plop down 150,000 for a truck like that. Maybe even get featured in rap videos and be a status symbol.
Alex Richardson: Smith Electric and Modec are two companies that manufacture electric trucks, used for local deliveries. While they are British companies, Smith Electric is starting a factory in California for the US market. They have several models, from 1/2 ton vans up to 3 ton carrying capacity, and have various battery size options available. These are not designed for speed or looks (though the Modec is rather nice) but are serious economical workhorses.
With all this talk of series and parallel hybrids, I must point out that Toyota and Ford hybrids use a split power path, with part of the IC engine power taking a series path through a generator and motor, with most of the IC power taking a mechanical path to the wheels in parallel with the 2nd motor. This combines the best aspects of parallel and series hybrids, allowing EV only operation like a series hybrid, yet having efficiency closer to parallel hybrids, In addition, the power split device and two motor/generators act as a CV Transmission, replacing the standard gearbox.
Another possible “Mythbusters” topic:
How about children in the passenger seat? What are the recommendations there?
There have been questions about the “waived airbags” possibly being unsafe for smaller children.
Autoblog green wrote something about it here:
www.autobloggreen.com/2008/02/10/is-the-tesla-roadster-safe-for-kids/
Would Tesla recommend installing a passenger airbag on/off switch like an Elise owner did here?:
elisetalk.com/forums/attachment.php?attachmentid=5507&stc=1&d=1098922048
Hi Rolf Bacher,
I grew up in Austria myself. Now I live in California.
That’s some very useful commentary on the state of the automotive industry today. The company that makes its own cars with its own parts is rare today. Most of the smaller niche car companies are in fact owned by the larger automotive corporations. VW actually owns much of the exotic car market. I think I’d be more concerned about the Tesla if it didn’t borrow some parts from other manufacturers. Those other manufacturers have a reputation that spans back decades. By piggybacking off some of their well-engineered technology, Tesla can use more of its resources on doing what it does best, which is integrating an electric powerplant into a customized sports car.
Not the worlds faster truck but it’s electric and they’re taking reservations for “early 09″ www.phoenixmotorcars.com/
FYI Worlds fastest (diesel) truck bankspower.com/sidewinder.cfm
Darryl,
Your explanation of design and implementation of the Tesla Roadster is excellent and I believe in the vision of a high end EV roadster. Do you ever tour with a Tesla as part of an exhibition, or similar events to show the general public what is possible? If so, where could I find out about these types of events?
My congratulations for the Tesla Roadster, I’m sure that he are at the daw of a new era of the automobile industry.
Does Tesla Motors have any plans to have the Roadster involved in motorsport racing?
The time used for charging the batteries could be an handicap, but if it was possible to have somekind of “fast charging” of the batteries (higher amperage, in a short period of time, instead of the “traditional” charging)
I believe that 24 hour Le Mans race will be won in the future by a electric powered car, it can seem distant today, as in the 1950’s it seemed distant to see a diesel engine to won Le Mans (audi did it in the last two years)
The very best success to your company.
Carlos Ferreira
I dont think fast-charging batteries would cut it on the track- even the new ‘nano-wire’ tech (mentioned elsewhere) would still take 3.5 mins from empty to full.
However, it seems to me it could be possible to design a battery which could be removed and installed v. quickly. Then it would just be a case of swapping the empty one for a full one. And, in an elegant evolutionary full-circle, since the batt in the Tesla goes in underneath, this would mean pit lanes would once again have pits! (Im assuming thats where the name comes from?)
Does anyone have any comments on whether or not 2 Roadster batteries which would be 106KwHrs and weigh 1 ton would have sufficient power for the Whitestar? And if so what would the weight do to the performance numbers in relation to Range and Acceleration ?
Yes Merz but in a 500 mile race you would only have to pit twice. How many times do normal cars pit ? Are 2 long pits better than 5 short ones ?
For electric racing, you wouldn’t necessarily have to rely on quick charging in the pits, you could actually have coils embedded in the roadway that would electro-magnetically recharge the cars as they go around the track. Such a system has been proposed for general roadways, but would be prohibitively expensive, and not very efficient. It might work well for a raceway though.
You could even make races more interesting by having a section of the track where drivers could choose two different paths. One path is shorter, allowing them to gain on their rivals, but provides no charging. The other one provides a charge boost. Drivers would have to manage how much time they spend charge boosting as part of their racing strategy.
Back to the original topic, the biggest myths of all are that electric cars are not practical, not affordable, and are not high performance. Tesla has already pretty much knocked out two of those three, now to go for the hat-trick!
If the Whitestar had twice the battery and twice the weight could it have pretty close to the same performance as the Roadster ?
Isn’t the tesla roadster based on a Lotus Europa?
@Kevin Harney
Don’t expect the Whitestar to have twice the battery & twice the weight. Twice battery is 2000lbs. Twice the roadster’s weight is 2700*2 = 5400lbs. That’s more than a big 7 series with the heavy V12 (4902lbs)! Consider the Whitestar’s main target 5 series is around 4000lbs; M5 with the v10 only weighs 4012lbs. If you make the Whitestar 5400lb you will make the efficiency worst. The best way is to keep weight around 4000lbs and keep the battery roughly the same amount. They should try to strike a balance between range, efficiency, and weight, aiming for 200miles. Increased weight also makes the car slower, braking harder, and handling worst overall.
I don’t think anyone here can supply a sure answer to you on how much battery is needed to power the Whitestar; we need to know a lot more about the design and probably a mule is the only sure way to answer that question. I would try to do an analysis but there is just no comparable EV around to make estimations. However, I can tell you the weight is most likely going to be around 4000lbs just based on the knowledge of the class of the vehicle. The V10 in the M5 weighs 530lbs, transmission most likely 200lbs. So that leaves 3270lbs with the most significant weight taken out. Throw the 1000lb battery in and you get around 4270lbs. Pretty good estimate of weight with just the roadster’s battery. Beyond the weight I can’t give more meaningful estimations. The Ebox mentioned by Gordon is 1000lbs less.
LOl Thomas J that would be awesome! Were you by any chance a fan of F-Zero? But unless cars are levitating soon they will still need to stop for fresh tires and stuff.
Hey Thomas;
“not practical, not affordable, and are not high performance”…”two of those three”… err… which one do you figure is missing?
It can’t be high performance. As for affordable, it’s just as “affordable” as other high-performance vehicles in the same class. So I imagine the “not practical” is what you’re refering to. With a distance of 220 Miles (354 Km), I’d say they already met practical. I’m in Edmonton, if I was going on a roadtrip, traveling south, I’d have to fill-up in Calgary. The distance is 171 Miles (276 KM). My F150 truck uses about 3/4 of a tank to get from Edmonton to Calgary. That would indicate my truck, on a single tank, can go approx. 230 Miles. I’d say 220 vs 230 is pretty darn close. The only thing missing is the infrastructure to “refuel” the electric vehicle.
After all, if the Esso gas station infrastructure neglects to put fuel stations in a certain State, one can’t really blame the Ford motor company for that infrastructure missing can one?
I’d say that with more electric vehicles on the road, the Electricity companies will realise they could play the role of Esso and start putting in the infrastructure. In other words: to be fully practical, it takes two industries:
a) The vehicle manufacturer
b) The fuel infrastructure
If Tesla Motors were to put in that second infrastructure, then they’d virtually corner the initial market. I don’t know if Tesla has considered being that supplier though.
With regards to requiring both industries, consider this:
Scenario: A fuel-cell vehicle is created that gets 150MPG and it has an EPA distance of 1,500 Miles.
But…. there’s no infrastructure in place to fuel it.
The vehicle would be more then practical if all you considered was distance it could travel on a single fill. When you consider that you can’t fuel it beyond that single tank it suddenly becomes very impractical.
I stand corrected on the distance. The previous was based on memory - which isn’t something one should rely upon - so I looked up some information.
Toyota Prius - Hybrid, 4.1 L/100 km, 45 Litre tank, 681 Miles distance.
Toyota Camry - 9L/100 km, 70 Litre tank, 482 Miles distance.
Ford F150 - 16M/Gallon, 26 Gallon tank, 416 Miles distance.
Based on that, I stand corrected. The electric vehicle has a bit to go before it matches current ICE technology distances. But they’re much closer then those EV’s that have a max distance of 60 Miles.
I am not saying that the Whitestar would be a light car that way but I am asking if the math and the physics are true or if I am doing circular math. If one battery can propel 2700 lbs 220 miles then can 2 batteries propel 5400 lbs the same distance? Or is there some greater force that makes that an impossibility ? I am simply hoping for a 150-200 mile range and acceleration in the sub 6 second range. How does the math work out ?
As with all new concepts, and start ups. Nobody has really gotten one, let alone the kind of person to take it apart to verify the claims. How do you NOT borrow parts from someone when the wheelbase and roof line are the same. If the wishbones up front are the same, that would usually mean it shares the same geometry on the front frame configuration. Tesla would have to develop the structure under there, and thus require further crash testing and DOT approval. I suspect that most of the frame is Lotus, with the needed modifications to structure to facilitate the use of battery packs and their weight.
Its ok to admit. We won’t get all “Cadillac Cimmeron” on you for doing so. For reality sake, I would really like to see the two disassembled and spread out next to each other. I find 7% a little far fetched, even for any other mfg, they would regurgatate plenty into another model (your powertrain issue is MOOT). To think a small company not using more from others is really not an economically feasable thought. Not on a $99k car. If Lamborghini uses some Audi parts, and they sell $300k cars, I really think this 7% is marketing hype. Glue on the chassis or not.
BTW: Someone from Tesla said it was like 10% shared in Car and Driver. 7 or 10 that makes a BIG difference.
I will give you credit, you got a nice concept here, and it will work, once the production ramps up.
Paulie;
You start off wrong right away! The wheelbase and undercarriage are NOT the same. Now what say you?
Kevin Harney: Whitestar is unlikely to use a “double size” ESS, due to the cost, but it’s not needed. Even if Whitestar was twice as heavy, (unlikely) the energy requirements would not be double. Additional weight effects efficiency in two ways:
1. it increases the load on the tires thus increasing rolling resistance. This effect is relatively small.
2. it takes more energy to get up to speed. In an old fashioned car, that energy is wasted when braking, but electrics and hybrids can recover most of that energy using regenerative braking. That means less energy loss for each acceleration/braking cycle.
So, you see, weight has much less effect on “fuel economy” for electrics than it would for old gassers. More important is aerodynamic drag, and I suspect that Whitestar will have a larger frontal area but a much lower Cd, resulting in similar or slightly less drag. Whitestar may end up using only slightly more watthours per mile than the Roadster, if they go all-out on streamlining it might actually use less! The old Toyota RAV4 EV averaged about 350 wh per mile, and that was in a small heavy SUV with the aerodynamics of a brick, Whitestar will weigh less and have much better aerodynamics. I’ll go out on a limb and predict Whitestar will use less than 280 wh per mile with a range exceeding 185 miles.
Thanks CM that was the explaination that I have been looking for…. So following the Battery blog ( Myth Part 3) then they could simply add 1 or 2 modules to the Roadster battery and still have the range of the Roadster. I assume from all of the conversations on the Transmisssion and gearing that the acceleration from 0-60 has more to do with the gearing that it really has to do with the battery. I do realize that it takes more energy to push more weight but as you said the rolling resistance does not change all that much.
Kevin;
Don’t miss CM’s point: it takes more to ACCELERATE additional weight; once you’re up to speed, weight has no effect. Only changes of direction and speed require power, and much of that is recaptured by regen in these cars. Narrower tires and streamlining have a major effect on rolling resistance, so it could even have comparable or better stats there. And since the performance requirements are lower, the very same ESS might well serve.
Thomas J, recharging the batteries inductively from the track in a racing scenario is a funny idea. I guess I’d say it’s half of a really good idea. The half that’s really good is getting the energy from the track while running; the other half is carrying a battery around. Why not just draw the motor’s energy from the track as needed, and not bother to carry a heavy storage apparatus? Seems like it would still be easy to spec a maximum current draw per-vehicle (of course they can just put max motor power/torque if they want) and if you want to put a few ultra-caps and/or smallish battery (say, in case you accidentally leave the track) then what the hay. Of course, drivers will still have to pit if they want tires and such.
Paulie, why so skeptical? That 7% number is just the parts that are straight from the Elise bin…anything (like the chassis) that came about by modifying the Elise design doesn’t count…just what you could pull off a Roadster and stick on an Elise. Also, I think I heard that same 10% suggestion…can’t figure out where (I checked C&D, but came up dry), but I thought it was Darryl, and that he said he was “pretty sure” that it was “less than” 10% …so this looks to me like he went and checked after he gave that quote.
CM, what makes you think Whitestar’s Cd will be lower than the Roadster’s? Just wondering, not saying it ain’t so.
I just found the 10% number in Automobile Magazine, attributed to Elon, not Darryl. Sorry for the mix-up.
Hi! What’s the fastest option to getting my hands on your car here in Europe? Buying a car in the States and then transporting it to Europe and taking care of all legal hassles myself or waiting to 2010 or whenever you are planning to launch in Europe? /Fredrik
Brian,
I did not miss CM’s point at all. But given that you will have to accelerate 150-175% the weight of a Roadster I think you will have to increse the battery size some to get in the same range as the Roadster. Also, I am with Hunter on this one - what makes you think that the CD on a sedan will be less than that of a small sports car that was designed to have extremely low drag? Not saying it won’t happen but I am highly skeptical. So how much energy does it take to accelerate 4500 lbs from 0- 60 in say 6 seconds? Can we then translate that into electricity consumed ? and compare that to the Roadster consumption?
The fastest way to get your hands on a Tesla in a Country other then the US: Get a wealthy person to go through the hoops of having the vehicle speced out to the standards of that country.
Otherwise, we all - I’m in Canada myself - have no choice but to be patient till Tesla Motors can afford to branch out into another market. Remember, they’re still a start up company with a lot more costs currently sunk into the Roadster then the income they’ve received.
Growing too fast is a recipe for disaster that many startups have chosen. Personally, I’d rather wait till Tesla gets established so they can comfortably afford to go through all the testing of another company then be bankrupt in a couple short years because they decided to move too fast.
Of course, I’ll be exceedingly happy if a wealthy person in Canada is willing to pay to have the Roadster cleared so it can be legally driven in Canada, but I can wait.
Kevin;
Much (most?) of that additional energy is recovered. So it isn’t a net “cost”. And if the 0-60 performance is dialed back to reasonable numbers, then the same battery output would be fine. So — the net increase in required battery power and energy would be a fraction of the increase in weight. My guess is ~20%, and it MIGHT be 0%.
@Kevin Harney:
Let’s not forget that most of the magazine reviews only got around 100 miles of range, even when the roadster was rated at 220. This may be also a function of the charge cycles on the prototypes, but it still shows that acceleration can hit efficiency by a lot. An easy estimation for your question is to use the 750Li (V8 360hp/269kW, 4552lbs) -> 269kW * 6secs * 1 hr/ 3600secs = 0.44833 kWh max to get to 0-60 (I realize in real life it doesn’t take all the power to accelerate the car from 0-60, but I’m only interested in the ratios). Roadster is 250hp/186kWh -> 186kWh * 4secs * 1hr/3600secs = 0.2067kWh. 0.44833/0.2067 = 2.17. So the 750Li uses roughly 2.17x the energy to get to 60 in a slower time. Now I’m not sure how well this translates to EVs (which is why I’m reluctant to do such a comparison), but you can see some of the difference there.
However some of the points you guys brought up is important. Since the EPA cycle will NOT involve full acceleration, the weight will actually not make as much difference since you are mostly going to be going steady speed. In highway speeds, drag plays an even greater role. However, that’s not to say a weight closer to 5000lbs isn’t going to have a strong effect on the car. The issues of handling, more effort in braking and acceleration still hold. At the target $65k price, the whitestar will at least have to perform on par with the middling 535i starting at $50k, 0-60 5.6 secs, 3660lbs. The RAV4EV brought up also doesn’t compare as that is at 3440lbs, 0-60 in 18 seconds, (which is why I said it’s hard to estimate whitestar’s energy usage). But I’ll venture to say that if they keep the 0-60 at around 5.5-6 seconds, weight to around 4000lbs then even with around the same size battery as the Roadster, I would guess it can get 200 miles on the EPA cycle, just guessing.
# “what makes you think Whitestar’s Cd will be lower than the Roadster’s?”
It will have to be. The roadster had to look great, so Tesla sacrificed a bit of aerodynamics for a sexier shape on the Roadster. But the Whitestar sedan will be half the cost, and can’t afford extensive use of exotic carbon fiber compponents. With 4 or 5 seats, it will be larger and heavier. The only way they can increase range without increasing cost is to reduce drag.
While a very low Cd shape can be nice looking, Whitestar won’t have the curves and large grille and hood vents that decorate the Roadster so nicely. On the other hand, it might have fender skirts like the Honda Insight, and a narrower rear axle like the late lamented EV1. It is entirely possible that the Whitestar sedan may end up with less aerodynamic drag than the 2 seat Roadster!
My take on the Whitestar is that they will get as much extra juice out of the battery pack as they can with newer batteries. Let’s assume they can use cells costing the same and with 20% higher energy density. Remember the Roadster batteries where speced out with what was reasonably priced cells around 3 years ago. The Whitestar will be using todays or next years reasonably priced cells. The hints we’ve been getting has been with a BEV around the $50k mark and a REEV version around the $70k mark, as well as anything in between. I’m figuring they will get EPA range figures around 150-200 miles, so lower than the Roadster to be able to price the Whitestar slightly competitively with the 535i f. inst.
What I suppose you might see is that the EPA cycle is nice to the battery so you get let’s say for the argument 175miles range. And since the Whitestar will have a more powerfull engine and even though it will be heavier than the Roadster you will get a good accelleration around 6sec as you do with EVs torque profile. BUT if you do use that 6 sec accelleration it will eat heavily into the range, so you can do sedate cruising and get around the EPA range. Or you will drive agressively and be prepared to cut the range down to 80-100miles. This isn’t any different than a dinojuice car of course, but it will just be very apparent on the display showing remaining miles left.
Still for my use a car that allows aggressive driving with more than 120km of range is more than enough range for me, so that would probably work nicely in Europe. Remeber the Think City has a optimistic range of 180km which mostly everyone thinks is fine.
Cobos
I would like to see a vehicle w/ a frictionless engine useing kenetic energy and magnets poss that could run in propetual motion.I’d love to own a Tesla but cost is too high right now 4 me.The Earth can”t wait obiously @ this point right .Thank you all very much.I’v just sold my 2006 GMC truck and will ride the buss untill I can get an electric car. I’m guessing there will eventually there will be a motor law on gas engines.Will I be able to get a retro fit for ss camaro? Thanks again
Dennis,
We would all love to see a frictionless motor that runs perpetually. But alas physics do not allow it
Cobos I think you’re off on a couple points there. First, the prediction that Whitestar’s cells will cost the same and get 20% more capacity seems pretty ambitious, and is probably due to you choosing the wrong timeframe for comparison. You note that they chose the cells 3 years ago. That’s true, but they didn’t *buy* the cells then, they are presumably buying them right now as they head into production. So the cost comparison is between right now and sometime in 2010, rather than 2005-2010. If price-performance is increasing about 6% annually (which I think I got from a long-ago blog here, not sure) then that’s a 12.36% increase.
Similarly, where are you getting these ideas about the range? Lots of people seem to assume that the EPA cycle misrepresents the range as too long, but I just don’t see where the evidence of that is. Take a look at the blog from a while back where they give the numbers they’ve gotten in the real world: www.teslamotors.com/blog4/?p=60 The “worst-case scenario” they posted was 165 miles (75% of the EPA number) of “impatient commuting, aggressive stops and starts, high speeds, and air conditioning on.” They also posted a “best-case” of 267 miles (121% of the EPA range). All their results fall neatly around the EPA number, depending on how aggressively they drove. I don’t see why you would expect Whitestar to have an EPA range of 200 miles and an aggressive-driving range of less than half that. It just doesn’t follow. Looking at the evidence we have, we should expect it to have plus-or-minus 25% of whatever EPA range it ends up with, so if you think EPA will be 200 miles, then you’re looking at 150-250 miles in the real world, not 80-175 as you suggest.
Also, stopcrazypp, as Darryl mentioned over at the club, the magazines did not completely deplete the packs, and had preproduction brakes with much higher drag than the final versions. They were also running the heater full blast with the top down and two big people in the car and running the car as hard as it can possibly be run, with multiple 0-60 attempts etc. Since you posted in that thread after Darryl, I’m not sure why you are using that clearly-debunked number?
“I would like to see a vehicle w/ a frictionless engine useing kenetic energy and magnets poss that could run in propetual motion.”
I would like to see pigs fly.
Hey Hunter there is a commercial out now that IS showing pigs flying !!!! LOL Doesn’t that mean it is real !?!?!??!
Hunter,
I think people look at the EPA cycle for regular ICE cars and have found over the years that it simply does not reflect reality. They know that this is with absolutley perfect driving by well skilled professionals with the intent of squeezing every last mile out of a gallon. And they assume that the same is true for the Tesla. Hopefully the new 2008 standards will be a better reflection of reality but I have not seen the new tests to know for sure ….
@Hunter
Also, stopcrazypp, as Darryl mentioned over at the club, the magazines did not completely deplete the packs, and had preproduction brakes with much higher drag than the final versions. They were also running the heater full blast with the top down and two big people in the car and running the car as hard as it can possibly be run, with multiple 0-60 attempts etc. Since you posted in that thread after Darryl, I’m not sure why you are using that clearly-debunked number?
Well, so far it’s still the only independently verified numbers, and even being the worst case I think it’s a good start to assume worst case first. I’m aware that they were running it hard with the heater on etc. Factoring in that they didn’t completely deplete the packs I remember it was still only around 120miles or something. So around 100 miles is good enough representation. All I wanted to show was the big difference in energy usage under full acceleration. This is true in gasoline cars too (which can routinely get less than half the mpgs on track days), except most people don’t need to care about range in a gasoline car since they can refill in a few minutes.
Weak dollar speeds Tesla’s European plans:
www.innovationbeat.com/2008/03/weak-dollar-speeds-teslas-european.html
At Dave D’s innovatiobeat link: Darryl hisself weighed in (about an hour ago), suggesting that the target market would be “much wider” than a few northern countries.
Brian,
Well of course !!!! If you are going to do the testing and qualifications to export/import then you might as well hit as broad a range as possible to include as many as you can in one fell swoop.
Kevin;
Heh; here’s the post I left there for darryl:
“darryl;
And you’re hardly going to the table empty-handed; any country facilitating approval and getting first dibs would gain major props. If you don’t think that motivates politicians, you haven’t been paying attention!
Of course, if the prematurely sclerotic Brussels bureaucracy could be persuaded to expedite things, you’d have the whole EU to play in. But I wouldn’t hold my breath.”
This is all well and good. I think this is the technology of the future; I think that the designs are stellar…but what is happening?? Specifically in Albubquerque? –No groundbreaking, no plant….no Tesla.
How sad.
Is it Bush?
Chavez?
Internal conflict?…. Were you paid off???
I am so sad and confused… :-{
# Jennifer said: “but what is happening?? Specifically in Albubquerque? –No groundbreaking, no plant….no Tesla.
# How sad. Is it Bush? Chavez? Internal conflict?…. Were you paid off??? I am so sad and confused”
Transmission problems. An unexpected problem with transmissions forced a delay in their Roadster production, and that took priority over starting construction on their new assembly plant. Now that Roadster production has begun, and a solution to the transmission problem is in the works, so now they can start designing and building the assembly plant for their 2nd EV model… right after they finish lobbying the California Clean Air Board in support of Zero Emissions Vehicles.
Ah, there are always problems to be fixed, but we’ll fix them, so don’t be sad!
Regarding carbon fiber body panels. The $500K Mclaren is mentioned for comparison sake. Please note the $70-$75K Z06 Corvette also makes extensive use of carbon fiber body panels.
# Dean Wolf wrote on March 26th, 2008 at 2:48 pm
## Please note the $70-$75K Z06 Corvette also makes extensive use of carbon fiber body panels.
Yes, scroll back up to my comment from March 6th, 2008 at 9:06 am…
stopcrazypp-
You said:
“Well, so far it’s still the only independently verified numbers, and even being the worst case I think it’s a good start to assume worst case first. I’m aware that they were running it hard with the heater on etc. Factoring in that they didn’t completely deplete the packs I remember it was still only around 120miles or something. So around 100 miles is good enough representation.”
Sorry, but I disagree that saying something is 83% of what it really is makes a “good enough representation.” I also think that it isn’t OK to ignore the preproduction brakes.
Kevin Harney-
You said:
“I think people look at the EPA cycle for regular ICE cars and have found over the years that it simply does not reflect reality. They know that this is with absolutley perfect driving by well skilled professionals with the intent of squeezing every last mile out of a gallon.”
Leaving aside the fact that the EPA cycle changed last year (in the hopes of more accurately reflecting real driving) I thought there were no drivers involved in the EPA cycle? That it was all done on a dyno with automatic control? In any case, there’s no “squeezing” going on…the cycle specifies exact resistance levels (think up/downhill faked by the dyno) and acceleration/speed. So, even if there is a driver, his hands are tied. But more importantly, the EPA cycle can be expected to more accurately reflect the Roadster’s range (as opposed to ICE vehicles) for a few reasons. First, the efficiency of the motor is relatively constant. Second, speed changes (particularly braking) are less wasteful. And third, the excellent aerodynamics of the car mean that high speeds affect the results less. In any case, having looked at Tesla’s real-world driving numbers (and having little evidence to suggest they are simply lying to us) I see no excuse for concluding as Cobos did that the best case range would be lower than the EPA range, and that the worst-case would be less than half that.
What about superconductors with magnets poss w/ batt power as an elect. hybrid? “Google search Maglev train check out superconducting train.” Cool stuff no ~phun.
@Hunter
“Sorry, but I disagree that saying something is 83% of what it really is makes a “good enough representation.” I also think that it isn’t OK to ignore the preproduction brakes.”
Sorry for the late response, but I’m just saying since those were the only independently verified real world numbers, those are the numbers we should start with. I’ll admit I shouldn’t have forgotten to mention the preproduction brakes. I think I meant that I remembered the mileage to be “around 100 miles,” which 120 miles IS around. It’s just a mostly qualitative comparison, so I think it’s a good enough approximation. Also, since the current epa numbers were gotten with the same preproduction brakes, the brakes don’t even play a factor into the comparison of mileage loss between the epa numbers and real world. I don’t know; if I’m doing formal, non-qualitative calculations I’ll dig up all the magazines I have on the Roadster and look at the specific numbers.
Since these are just tests on prototypes, I don’t think we need to get so uptight about underestimating the Roadster’s range. It’s best to underpromise and overdeliver. We’ll find out how the production models fare when some tests are done on the final versions. If your worried I’ll misrepresent the Roadster, I won’t; I usually use the EPA number when discussing range of the Roadster.
In the meantime, I wonder what the next part of the “mythbusters” series will be. I can’t seem to think of some good ideas so far, but I’ll keep my eye out for any myths that may occur about Tesla.
Good post…..Nice to read it. People will really appreciate….
Hi !
Please, what is the Cd.A of the Tesla Roadster ?
It’s quite difficult to find the info… Is it top secret ? ;o)
Is it the same than Lotus Elise ?
Thanks by advance !
Steve.
I hope the third car won’t be sold off to GM. It’s unfortunate if Tesla does do a ridiculous joint venture with a NON-EV automaker.
Hi !
Could you tell us what is the energy efficiency, in % , from the outlet to the wheels ?
I guess it’s about 50% but I’d like a confirmation, please.
In other words, what are the losses (in %) for charger, batteries charge/discharge, wires, electronics, motor, gear… ?
Thanks by advance,
Steve.
I look forward to the day your production volume gets the price down to “mere mortal affordable.” Offer a car in the $30-$35K range and folks will line up around the block to buy one. Make it a four door sedan,roughly the same size as the original Saturn to Malibu for wide spread use.
The Tesla seems a succesfull combination of technologies and afaik…. they’re produced at…. Lotus.
Although you can say the parts shared are only 7%, the main thing here is that Lotus has been willing to share technology with Tesla. Lotus is one of the very few companies left in the UK who’s still producing low volume dedicated ‘driver’ cars.
In my opinion, it’s good of them to be willing to share their technology and a perfect partner for Tesla. It will probably also help them to move into the green era of automotive.
As for the comment earlier on about Lotus being inferior etc. I think you should re-read the comments here. Obviously, you don’t know a lot about the company and to be quite honest, most people only know small bits. Lotus is a highly respected technology driven company which is involved in a huge number of new cars. Not only the fancy stuff, but also normal road cars are part developed by Lotus. Specifically the ride and handling department is rather famous for their inputs.
Don’t be shamed by comparisons to Lotus.
After reading about Tesla Motors not supplying into the UK I decided to make my own EV sports car from a 1998 Elise.
Having stripped it down to re-build in EV form, I can tell you the build quality is far better than you read about with features such as interlocking aluminium extrusions used for the dash board etc. The planning must have been exceptional.
The chassis is superb and it is a treat to work on a 10 year old car without rust! Virtually everything is aluminium or GRP.
Carry on the good work Tesla Motors. I would not have my project if you hadn’t.
Regards to all past and present at Tesla.
Your whole response is so defensive - all that stuff about 7% shared parts etc - you have made the smartest decission to use technology Lotus have developed over years with some brilliant minds and match to your incredible technology. The Lotus derived chassis itself is a substantional part of the car as in the body work and in my opinion superb designs. The combination os Tesla and I cant wait to try one and hopefully buy one soon too. I have a Lotus Exige S and an XJ jag Diesel because both are amazing pieces of technology - combining light chassis with efficient engines. ps the Jags engine is was developed between citroen, peugeout, and ford and used in loads of cars and even the LandRover.
Embrace the incredible design of your car - you dont need an excuse because what you are making it the best of its type.
Andrew Hurdle
Thanks for the great post. I was wondering this as I also saw the similarities between the Roadster and the Elise, but this really helped clear things up. There could be much worse things to be compared to, as the Lotus Elise is a great car in its own right.
Wheelbase is subjective, a fiero based Lambo kit is streched 6 in to provide proper gemotry. As for the Tesla Brian. Explain the Greenhouse, C Pillar, and the rear quarters lining up on a superimposed image. They are almost identical. This could not be a coencidense. It still leads me to belive this is about 90% lotus under there. With, granted a (as I said before), few mods to support and accomidate the electrical drivetrain. Slap on a wide body kit, and some new tail lamps, and TA DAH!!
Just a shame they named it after a Genius. Should have called it the Edison, he faked a lot too.
I previously said that the Audi A8 used carbon fibre for its body panels, when I meant the R8. I’m pretty sure that’s accurate.
“In order to accommodate the added weight of the battery pack, the aluminum tub chassis had to be r e d e s i g n e d to a Tesla specification, increasing strength and using the battery pack as a stressed member to increase rigidity. Since we had decided to r e d e s i g n the chassis, we also chose to r e d e s i g n the side rails so that they would sit a few inches lower than those in the Elise, greatly improving ingress and egress.”
truly, a great explanation why this is n o t a c o n v e r t e d Lotus…
this is your web site, I will not feel offended if you do not post it, but please, fix it.
I think sharing parts with the Lotus is a good thing, then it´ll be easier to find used parts in the future.
Wow! What an achievement. I would just like to say that we need this car, and its infrastructure, in Australia, as soon as possible. Please keep up the good work. Electromagnetic fields are a concern, however, and need to be discussed.
Why aren’t you using “brake by wire” system akin to the toyota system with a electric pump to pressurize the abs accumulator for brake force? Sorry, couldn’t help but throw it out…
” Lamborghini cars share upwards of ten percent of their parts content with Audi cars “, … not to mention how much of an AUDI is shared with a VW….
but who cares… certainly not the consumer. The consumer cares that AUDIs are front-wheel-drive (VW dependency) and that you need to pay for the Quattro version to get decent handling. That is why BMW is still a stronger brand.
How many Ferrari parts come from FIAT ?…..do we care ?
Shared parts stories only resonate with the consumer if the sharing leads to a deterioration of the core brand promise.
Vittorio
Ok, so the problem with this to me is that the 7% or 10% comes from total parts shared with Lotus. What people see is a car that looks very similar to the Elise and shares a large number of structural elements. I think if you told us, what percent of the car is a lotus by surface area or by volume, it’s be a lot larger than 7%. I also question what you call ‘a part.’ Is the motor a single part, or is it made up of 60 parts. If you are innumerate every bit of electronics in the drive controller as a separate part, you could get the number probably even lower than 7%.
Excellent YouTube post ! thanks for sharing. I’ll be adding your blog to my reader.
Juan