Are EREVs the biggest threat to Tesla?

Are EREVs the biggest threat to Tesla?

Elons goal is to electrify transport. Which is nice, but to get decent range you need to go large on the battery pack. Or stop regularly and longly for recharges.

Big batteries are expensive.

BMW took a different approach with the i3 and stuck in 22kWh and a 650 cc bike engine they had lying around their parts department. Not particularly economical, but it gives you peace of mind that no matter what charging station issues you get, plan b on journeys longer than 75 miles is that you can stop at a gas station and top up for another 50-75 miles range.

I think theres a possiblilty the EV experience could catch more people if say BMW and other competitors to Telsa started bringing out small 20-30kWh pack cars with 50hp generators, with only final electric drive to reduce all the mess of bits that GM had in the Volt.

It looks quite feasible BMW could bring out an i4/5 for about £40,000. (i3 is £33,000) plus options. stick in a slightly bigger motor, bit more battery, make it more sedan shaped than city, and you have a car the public won't feel anxious about buying. IF it also has say a 20litre fuel tank instad of the i3 9 litres.

As much as I like Telsas approach to go for the full EV, it puts it up the price, well above an smaller Pack plus ICE well until the 2030s.

Then again, I'm pretty sure Telsa recognise this, and that frunk space has been left empty for a reason. Just in case ;)

Could be interesting times up ahead.

[Edit] An EREV is an extended range electric vehicle. Final drive electric with an auxillary power source (usually ICE). Also known as series hybrid.

DTsea | 2 november 2014

Tesla will never put an ICE in their cars. There is no need.

30000 miles in my model S and I havent missed ICE cars once.

gipfeli | 2 november 2014

@cmcnesttt +1
I was a BMW fan in the past 10 years (one of my car is still a BMW).
Since I discovered the Tesla technology and tried the MS, I am now a fan of Tesla. To me this is quite clear, any mixed technology as currently proposed by the "old" brand, demonstrates a kind of "non willing to change" or "difficulty to change" their design. The full EV is one of the solution for future transport. Tesla does already provide such product.

Anemometer | 3 november 2014

I think the point Im trying to get across, is theres a window in the next, say 10 years, where to get a vechile that can do the magic 300 400 miles range, its going to be cheaper to stick a small petrol motor in the car somewhere, and this puts Telsa at a weight and cost disadvantage having 85kWh of batteries to carry around. I'm a purist and would love to think everyone else would prefer a Tesla but I dont think thats the case, when it comes down to cost. You can still get the EV grin without having to have a huge battery.

Say if other manufacturers start making cars with 100 mile real world electric range, plus another 200 on gas REX then potentially that could cut off a chunk of Telsas market, depending on how many trips people make over 100 miles regularly, They would obviously have to offer lots of power, light weight and nice styling, but that isn't impossible.I used the BMW i4/5 as an example as I'm assuming its probably on a drawing board somewhere and I know that when it comes to purchase time, say in 2018 and theres a choice between an i5 or a Model 3, it could make choosing a Tesla a little more difficult. Especially if the i5 had a 300kg weight advantage and better driving dynamics.

The other opiton is that other manufactures start using the CCS standard and pushing the charge rates, they are rolling out with 50kW, but the standards cover up to 1000V/400Amp DC or 400kW. That will only come when the cars can take it, with their small 22kW packs Im assuming they arent capable of taking much more that this as the cell count will be low so you cant get much going in in parallel.

I agree that by the 2030s the ICE REX wont even be an option as it will just be cheaper and probably lighter to go pure EV, but Im worried that Tesla strategy could behijacked by ICE makers in between now qnd then, assuming they coukd design a task specific motor instead of the one in the i3 which was an adaption from an existing scooter engine,

3seeker | 3 november 2014

I doubt it IMO. Once people get used to the EV part of the vehicle - the convenience of charging at home or work, the instant torque, the quiet motor, the lack of vibration & gear shifts, ease of maintenance, lower cost of ownership, etc. etc. etc. - I believe they would dread the ICE part.

As a hybrid owner, I experience the stark difference first hand. I don't like it whenever I feel the gas engine turn on; and I surely dislike going to the gas station weekly for a fill up.

The biggest obstacle for EVs is overcoming slow charging and range anxiety issues, as well as changing society's perspective. Battery weight should go down in the future as the technology improves, so I don't believe that will be an issue.

Sin_Gas | 3 november 2014

What does the ER in EREV stand for?


txgreen | 3 november 2014

ER = early retirement

Bikezion | 3 november 2014

ER= engineered regression

Brian H | 3 november 2014

EREV = Electric Range Extended Vehicle

A couple of points:
-the i3 putt-putt is NOT recommended for actual travel, only emergency return to a charge point. Do NOT count on it for daily travel, e.g.
-charging at a mile a second is fantasy stuff, well over a MW of power continuous. Only internet dreamers dream of it. Magic is not an option.

Bikezion | 3 november 2014

EREV = extended range electric vehicle

Bikezion | 3 november 2014

Anemometer | NOVEMBER 2, 2014

Is a duck the biggest threat to an eagle?

Larry@SoCal | 3 november 2014

As Brian H implied, you can run only so much current down the wires, both on-board and at the Supercharger end. The numbers are available but we are not going to get much more. Battery swap will be the next great thing.

Rocky_H | 3 november 2014

" theres a window in the next, say 10 years, where to get a vechile that can do the magic 300 400 miles range, its going to be cheaper to stick a small petrol motor in the car somewhere"

Really? You're talking about Tesla should make a different type of vehicle for a short term 10 year time period? If it's cheaper to have a gas car, just have a gas car. Plenty of people can just continue to drive whatever gas cars they have for that next 10 years, while long range electric cars continue to come down in price to the point where all of the positive factors are on the side of the electric vehicles, and then it won't matter, and it's a landslide in favor of EVs.

al | 3 november 2014

for those who may love the ICE as a back up to the Electric motor...I am reminded of the old electric car rally's...yes we had NY to challenge at FSEC..and wheel to wheel racing in Phoenix AZ. Where One contestant pulled a sleek trailer with a generator ? This too cowboy

Grinnin'.VA | 3 november 2014

@ cmcnestt | November 2, 2014

By 2025,but probably earlier, you will be able to Supercharge at 1 mile per second or 300 miles in 5 minutes.

Please explain.

Ron | 3 november 2014

@Anemometer, Brian H
I fully agree with our statements.

BMWi3 is a niche product - a hybrid in the true sense of the word (50/50 approach). Compared to an e-Golf, it is much lighter and therefore much more agile (gives you a BMW-like feeling). In fact, the pure e-Range is "enough" for day-to-day urban drives.

As Anemometer pointed out, there is a lot of flexibility in this approach. BMW can easily put other motors "off the shelve" or add more powerful batteries, if available.

However, i3 is an electric car (performance values) but with an extender to give you peace of mind - no bad for an "average user". Please have in mind that this approach also gives you a safer feeling in hot summer and cold winter - the REX is not only a "range extender (in miles)" but also a "power extender (in kWh)"

It is not intended as an alternative concept to either an i8, aiming at ICE-performance with an plug-in hybrid, nor to a full-blown S85D.
Maybe it's a niche market, but it sells very well -> makes shareholders happy (at least in the next 10 years) :-)

BMW currently sells gas, diesel and hybrid cars; is it unimaginable to add "true hybrids" to that model palette? Why either/or, why not compromise?

Anemometer | 3 november 2014

@Rocky I'm not saying Tesla should do anything. But I think joe Public might be inclined to choose a smaller battery REX type vehicle over a BEV based on cost. Hence a threat to Telsa. Such a vehicle doesn't exist yet of course. But looking at what say - BMW have built so far in their i range, expecing a BEV only edition for an i5 might be an incorrect assumption.

@Bikezion. Ducks and eagles??? Do Ford/GM/etc sell ducks or eagles? Maybe it's an american saying I haven't heard before.

@Brian H : the i3 putt-putt is NOT recommended for actual travel, only emergency return to a charge point. Do NOT count on it for daily travel.

That's only for USA as they knobbled when the REX fires up. I did a lot of reading up before ordering mine (in UK). There's people over here using them and doing long journeys at higher than legal motorway speed as we got the option to fire up the REX once the charge drops to 75%. I've currently got a 150 mile "commute" on Sun/Fri to my rented secodn home for work and am happy it will suit me. Probably at the top end of what you'd want to do on a regular basis.

I agree with everyone - once we get the larger public to understand, and range anxiety and public charging issues are sorted then there's no problem. The problem we have a the moment and maybe even when model 3 comes along, is that it will be cheaper for say Ford/Toyota/Nissan etc to stick a small REX in along with their 22kWh packs to get the range that people fear they need. Although the model 3 will be BMW 3series priced that's still a huge part of the market untapped.

Oh - yeah I forgot to in cluide in the post - EREV = Extended Range Electric Vehicle. Bascially an electric final drive with some kind on additional power source for the extended range. Currently ICE.

Persoanlly I'd have preferred the i3 used the additional 100kg the REX added to stick and extra dozen kWh of batteries. But I'm not "The Market". What I have been reading is lots of issues with public charging where for example CCS chargers have let people down, and the REX has been the preference to getting stranded.

Its very easy when taking a Tesla centric view of the world to forger that not everyone has £/$50,000+ to spend on cars (me included). I could borrow the money and pay it back, but refuse to do so because of the interest cost would buy 1/2 an i3.

I don't think EREVs will ever hit Tesla's Model S sales, its when you get to the Model 3, that I see the risk to Telsa's current strategy. All depends of course on whether the competition go for it and start bringing out 200+ mile BEVs. In that scenarion the competition will be more balanced on cost and weight. But a bit in Telsa's favour ;-)

I think Telsa will probably sell all of their 500,000 units a year, if there's enough people like me who are happy enough with a 200 mile BEV. However EREVs could eat up the market that could have seen Telsa expand that to 5,000,000 a year.

Just as an example - the i3 has been selling in the UK about 60/40 in favour of the REX. Not much use as a comparison as that not a comparison to a 150 mile BEV - which is the range of the i3 REX. No one sells one yet. A real comparison would be say a £40,000 i5 REX vs a £40,000 Tesla Model 3. Will have to wait to find out.

Anemometer | 3 november 2014

PS I seem a bit of a BMW fan boy reading that back. It's only because the like of Audi / Nissan are bringing to market with the BEV is not a threat to Tesla with their limited 75 mile range. It's BMW REX range that concerms me... becuase I'd like to see Tesla be a success.

aljjr2 | 3 november 2014

An Electric Vehicle with Extended Range may have general appeal. I drive my EVer purely on Battery 70-80% of the time. With 40-50 mile range and three levels of regen, I only add 10 gallons of gas every 2-3 months (130MPG). That gives the freedom of never having range issues. If the new model extends the old 2010 battery technology to 100 miles, it could be a game changer. The only draw back is the price -- still $100K.

If the Chevy Volt -- ER/EV can keep the price down and extend its range and keep the $35-40K price range, it would be a contender for the model 3. So will be others in development.

I enjoy driving on battery, zooming around on $1.00 at 400 HP electric motors.

I will not expect to win the debate here. Not anti-Tesla, I have a Model X on order, so I too support all that TESLA is doing and stands for. Elon Musk and Hendrik Fisker debated this years ago before departing ways.

I merely suggest keeping an open mind to other EV solutions that the general public, not just early adopters, may ultimately embrace.

Remnant | 3 november 2014

Maybe I'm not evolved enough to deal with it casually, but rampant misspelling and poor grammar on these threads have become a nonsensical obstacle to smooth communication. It would only take a couple of minutes to the authors to scan the texts they've produced and fix such problems. The text one posts should not become a puzzle for the readers. Besides, to keep spelling Telsa instead of Tesla is even disrespectful, IMO.

But to return to range extenders (REX's), to be be appropriate to the principle and purpose of BEV's, a REX must be silent and non-polluting. Only chemical generators can do this. Hydrogen FC's can, at a prohibitive cost and horrendous pollution behind the Hydrogen production.

However, there are other chemical generators, such as the Metal-Air ones that can do the job properly. You can keep such a REX on your garage shelf and only load it in your Tesla on the rare occasions when a very long trip makes it impractical to rely on grid recharging.

By the way, Tesla did obtain a patent for such a REX a while back. The Alcoa-Phinergy Aluminum-Air "battery" is an example of current technology that can be used for a REX. The only thing you would need beside the REX itself is a DC charge connector in the frunk.

grega | 3 november 2014

A really good EREV is a threat to EVs in general.

We have a significant gasoline infrastructure, significant experience using and servicing ICEs, a need for occasional long range, and a long range tank costs the same as a short range tank. Plus big batteries are expensive and in limited supply.

So done right an EREV threatens to avoid pure ev need entirely. A good EREV needs to function brilliantly in EV mode and cover over 90% of your needs, preferably much more. The performance needs to stay the same even in range extending mode (probably meaning the generator just charges the battery). . And preferably the generator should be as small as possible and very fuel efficient.

The challenge here is battery technology and CARB. Small batteries limit performance and regen. An almost depleted battery has low performance too - but CARB wants the generator switched on as late as possible, which reduces performance OR requires a bigger generator. And CARB forces a small gas tank.

Which leads us to the 2 potentials today: i3 (low performance in extended mode and small tank) and the volt (bigger generator, also still used to power car directly). But get a better power output (add a 1kWh capacitor?) and large tank and many city drivers won't see why you'd look at pure EV.

grega | 3 november 2014

Edit :)
.... But get a better battery power output (add a 1kWh capacitor?) then performance increases, a small generator doesnt reduce performance at all, and a large gas tank is there for occasional long trips... ICE servicing is expected and gas stations are everywhere.... and many city drivers won't see why you'd look at pure EV.

Anemometer | 3 november 2014

@remnant - sorry my spelling and gmamma us much better when I'm on the pc instead of teh ipad which ois rearlly. ;-)

The text is so small and the window you get to type in on the forum means it's almost impossible to see any mistakes till you hit submit. That and the auto replace working against you. A forum edit post would help no end!

grega | 3 november 2014

@Remnant, you wrote "to be be appropriate to the principle and purpose of BEV's, a REX must be silent and non-polluting"

I don't think that's right, whether as a Tesla competitor, or to be appropriate to the purpose of BEVs - particularly if the EREV is truly using electricity 90-99% of the time.

Selling twice as many EREVs as EVs would be less polluting in the short to mid term. And while I am certain that in general creating and refurbing batteries instead of using gasoline is better for the environment, for the average user I'm not sure whether a smaller battery + ICE vs big battery is more eco-friendly (when the second half of the battery, or the generator, is very rarely used).

As EV technology matures, an EREV should also be theoretically cheaper than an EV (less battery cost, + ICE experience making generators cheap).

It is a "dangerous" path though, in the sense that it may halve our pollution more quickly than the pure EV path, and yet it holds the umbilical cord... it still discourage the development of a common supercharging network and thus retain a reliance on gasoline. And rarely used generators will need more servicing.

On the positive - it would still encourage a battery development path and related technologies, and long range EVs would still have to be designed for pollution free driving (an EREV in principle is a city vehicle with occasional longer trips), plus every city EREV could theoretically have the ICE removed and an extra battery inserted.

Bikezion | 3 november 2014

Brian H
EREV = Electric Range Extended Vehicle ;

Is this like a stove in a limo?

Tiebreaker | 3 november 2014

Does it mean you get an EREVTION?

Red Sage ca us | 3 november 2014


No. The lies that traditional automobile manufacturers tell about them may be, though. Once someone actually drives a Tesla Motors product, the difference, and the lie, is clear.

carlk | 3 november 2014

Would I buy the band-aid car? NO!

Brian H | 3 november 2014

The 200+ mi M&8801; will blow the REVs so far out of the water they'll never come down. Dead end junk technology.

Brian H | 3 november 2014

typo: M≡

grega | 3 november 2014

@Red Sage Once someone actually drives a Tesla Motors product, the difference, and the lie, is clear.

Are you saying that if Tesla (in a bizarro universe!!!!) made a car with a 650cc range extender, and a 25kWh battery, they couldn't make it an amazing car?

I definitely don't think they would, and I wouldn't want them to, I just think it is possible, and it would be a threat to EVs (as the thread asked).

Red Sage ca us | 3 november 2014

grega: Uh, no... I didn't say that at all. I believe it is well stated and fully documented that Tesla Motors will NEVER build, design, engineer, or contribute to the development of any form of hybrid or 'range extended' EV. So, the difference between a Tesla Motors 100% BEV, as compared to one of the liar, fire, pants alight, hybrid gimpmobiles will be blatantly obvious upon a test drive of the two examples of 'zero emissions' automobiles and stuff.

grega | 4 november 2014

Oh. Okay. So your take is that a hybrid could be competition to Tesla if Tesla made it, but the other companies won't do it well.

I tend to agree that they're getting it wrong so far. Just not willing to predict the future. | 4 november 2014

one more thing:
Chevrolet Volt has an electric range of 30-50 miles, >300 with REX, while BMWi has 100miles electric, 200 with REX.
While both are REXs, the underlying philosophy is completely different.
An i5 therefroe should have 200/200, to follow the same philosophy.

BTW: some people propose to use a Wankel-engine as REX: advantages: small and very quiet. And, as REX, the problems of a Wankel-ICE (like high oil consumption under full load) could be avoided - BUT: a Wankel-engine has to be developed, while a bike-engine can be used "from the shelf"

grega | 4 november 2014

Thanks realo

Interesting read on the Mazda 2 EREV.
330cc wankel engine, low noise and vibration, 28kW, 45mpg.

Brian H | 4 november 2014;
There. Will. Be. No. Fuel. Engine. In. A. Tesla. Ever.

Blather on.

Sin_Gas | 4 november 2014

"There will be no fuel engine in a Tesla". I certainly applaud this position and Tesla can certainly address the BEV market. As long as the current demand continues, this will work.

However, if Tesla gets in a position where the EREV or PHEV is taking over the market, and if they cannot make a profitable business with BEV alone, they will have 2 choices. Either they can live or die with the BEV business, or they can compromise and go EREV or PHEV and attempt to grow. I don't want them to do that, but I am sure that under Elon's leadership, an EREV or PHEV would be the best one available. I view the window on BEV's is open now, but with the competition from EREV and PHEV, it remains to be seen how long that will be the case.

Never say Never.


grega | 4 november 2014

Brian, I was going to say that tesla adding an ICE isn't really what this thread's about - instead it's whether these cars are a future threat to tesla.

But then I reread the original post. Oops.

JeffreyR | 4 november 2014

Thanks for the thoughtful post (and clarifying edits). I believe the time horizon to "beat" the Model ≡ is only a few years not a decade plus. So the hypothetical i4/i5 would need to be in production soonday. By 2020 the M≡ will be at 500K units/year and have a short wait (~3 months). Even w/ the added weight it will drive like a dream especially the D version. W/O the bigger battery you won't be able to wring that much juice in/out so your performance will be hampered. So comparing a small battery RXEV w/ a pure BEV Tesla will not be very interesting. Think of this as the Tesla bookends for the next phase:

Model ≡ 45 (base) — starts @ $35K, 0-60 MPH in <5.5 seconds and 200 mile range EPA-5
Model ≡ P60D — starts @ $49K, 0-60 MPH in <3.5 seconds and 270 mile range EPA-5

The M≡ will be 20% smaller (so lighter) and have next-generation batteries so a smaller battery will have similar performance to the current, larger Model S. That's the great thing about an EV, the motor is so compact and simple you can use the same one(s) in a much smaller car.


P.S. You can do a few things to help yourself when writing on an iPad. (1) Pinch to zoom the text input box. If you are horizontal you can get the text quite large. (2) Use the Notes App, then copy-paste into the input box. This helps you in another way as you won't lose your text (like I just did on this post script) if your session has timed out or you switch tabs and Safari reloads the tab. You can also start a post on one device and finish it on another w/ iCloud. Hope this helps!

— Written on Galveston Island, TX (while California dreaming) on an iPad.

Check out the Tips & Tricks for searching, posting pictures, and other useful tidbits. | 4 november 2014

@Brian H
Read on


There is a new Mercedes B electric: 200km, 180PS => the market of 200km is emerging… | 4 november 2014


I fully agree. EREVs will, in my opinion, primarily be positioned in the small car market. For the luxury sedans, I rather see the plug-in hybrids as competitors for Tesla.

Considering M3, the possibility of an EREV competitor is an open question: a 30kWh/30kWh EREV could compete with a M3 (60kWh) concerning range, but would only deliver "30 kWh equivalent performance". However, such a car is much lighter than a 60kWh EV and therefore provides a much better agility. Moreover, the 30kWh battery provides "enough" range for daily drive.

Timo | 4 november 2014

Weight difference between 30kWh and 60kWh is about 150kg in pure batteries. I wouldn't call that "much lighter". Also because of smaller battery you probably would need to use higher power density batteries which usually have much worse energy densities making that difference even smaller.

Model S 85kWh battery pack (not just the batteries in it) weights about 600kg: 600kg/85kWh = 7kg/kWh, 30*7 = 210kg and that's with (now) old battery tech. It also doesn't scale quite directly, smaller pack still needs same amount of protection.

Add in the ICE and the required accessories and you have mass difference that is pretty much negligible. If that ICE is big enough to provide enough power to maintain highway speeds, then difference could well be other way around. The heavier of the two is the one with RE.

JeffreyR | 4 november 2014


Excellent points. On top of what you added you also can add a much lower center of gravity, "digital" vs. "analog" traction control (even w/ two wheels), a much, much lighter AWD option w/ better range, quickness, and traction. Hard to do AWD w/ a RXEV due to space and battery concerns.

I can see your point for a low-end RXEV, but I think it would need to be very cheap to make a dent. It will definitely be a while before Tesla plays in the very low-end market (if they ever do, unless they like the C-1). I don't see the legacy automakers being able to do it, but would be pleasantly surprised if they did.

Red Sage ca us | 4 november 2014

Realo: The BMW i3 REX was engineered to meet a specific provision of CARB compliance. It allows the vehicle to qualify for a higher level of ZEV Credits as long as the ICE range is 50% or less of total range. In other words, traditional automobile manufacturers are forced to build gimpmobiles to get the benefit of the regulatory provision, or... Put up and shut up by building the car with battery electric range of 100, 150, or 200 miles, if they want the ICE part of the 'extended range' vehicle to have more range. That's why the BMW i3 has a teensy, weensy, itsy, bitsy, two gallon (1.9) fuel tank. Oh, and its total range is only 150 miles, not 200.

Red Sage ca us | 4 november 2014

Sin_Gas: The Fisker Karma was the 'best ever' example of the extended range PHEV. And... Well... You know. Yeah.

Realo: No. The PHEV versions of luxo-sedans are less capable, both in range and in performance, than the 'straight' hybrid or diesel versions are... They can't even compete within their own product lines, let alone against Tesla Motors. That is done on purpose, to perpetuate the fable that 'adding a plug' always means you must give up something. None of the traditional automobile manufacturers will ever build a car that is truly 'the best of both worlds', because they only truly believe in the existence of the ICE realm.

JeffreyR: I believe Tesla Motors will never build a car with less than 200 miles of usable, verifiable, honest, actual EPA rated range. A 45 kWh battery pack would not reach 200 miles in a car the size of a Model ≡, projected to weigh around 3,700 lbs. The car would have to be under 2,800 lbs to have a chance. For the sake of comparison, the Fiat 500e has a 24 kWh battery pack, and weighs 2,900 lbs. It has an 87 mile EPA rated range, so even if it weighed the same and had twice the battery capacity at 48 kWh, that car would only have a 174 mile range. | 4 november 2014

thanks for the explanation about the ZEV-credits (nothing like that in DE).
Range: the "official" numbers are 150+150km, realworld range of course is less (see tests) - but also, the tank could easily be enlarged (not for the US).

2. luxo-sedans
maybe I was not clear here: my position is: beside ICEs (gas, diesel) I foresee more plug-in hybrids (say 10/90 range). Even in their model palette, they are less capable - fully agreed. Moreover, I don't foresee RXEVs (in the order of 50/50) here, primarily because of performance aspects. Therefore, RXEVs are no threat for Tesla in the Model S segment.

one last point:
However, what I foresee is an evolving market in the entry-level EV-class (see above): the first cars were about 15kWh, today 20kWh is the standard and I foresee a trend towards 25kWh and 30kWh, full electric (like e-Golf, Mercedes B). Here you see a trend towards a broader model palette (you can buy an ICE-golf (super, diesel), a hybrid and now an e-Golf), same for Mercedes B). Different business model than BMWi or Tesla.

I foresee a certain competition here for Tesla's Model 3, at the mid term, if the "traditional car companies" provide models in the range of 40kWh.
To me, it is still an open question whether a blown up eGolf (say ePassat) or a down-sized Model S will dominate the 40kWh market and how they compete with the hybrid Golf…

grega | 4 november 2014

@Realo, Japan has the same rules as California when it comes to EV vs Petrol range - so they make their EREVs with very small tanks too.

The brilliant thing is that there are multiple different attempts at 'getting it right'. Prius, Mazda2, Leaf, ModelS, Model ≡, i3 etc. Their big differences will lead to several failures, and a lot of learning and improving.

And I agree we're going to see a massive growth in the 20-30kWh end of things - the question is what they end up offering from that point.

Having read up on Mazda 2 EREV last night (their own design, unlike the Mazda 3 Hybrid which is literally a Prius), I saw the Mazda Australia comments which are along the lines of "We'll sell the economic petrol engine Mazda 2, but we won't sell enough EREVs to bother launching the battery version in Australia". So the concept of "same car, different drive train" doesn't seem to extend to selling both versions.

Ah well. They all have to start somewhere, trip over themselves, start again, trip again, start getting it right, and market more broadly....

Anemometer | 4 november 2014

@Timo: Like the approach. Nothing like a bit of cigarette packet maths to get my attention.
Got me thinking – lets forget fictional EREVs. Lets look at the i3 as a case study and see when it would make sense to become totally BEV to get the same range. There's a caveat here... although I'm going to look at upfront costs, most potential owners would, I hope, work out their expected usages and work out the gas savings. But to make it simple lets look at direct range per unit cost. I'll stick to $ as even though I'm in the UK, most people can convert easily enough and I think most readers are in the US. That said, I'm sticking to kg :-)

The rest of ICE-land won't have access to Tesla's batteries(yet). So I looked up the i3 battery weight. 230kg for a 22kWh battery or 95.7Wh/kg.

The REX comes in at 1,315kg vs 1,195 for the BEV. So an extra 120kg. (

The cost in USA for the REX is $45,200 vs $41,350 for the BEV so an additional $3,850.

Next costs... this are a bit pie in the sky – but the article above quotes a figure of approx $11,000. This is consistent with something I read somewhere once about a Nissan Leaf 22kWh replacement battery in the UK costing £6,500.

I'm saying you need a 50kW pack to get the i3 to a decent range – nearly 200 miles, which is the minimum I think most normal people would accept as a long term minimum to make the car your only vehicle. This may change, but lets assume Tesla did the research and that's why their base 60kWh model has 200 miles range.

So now we know the current state of play for BMW, apply the 7% yearly cost decline and the 8% per year energy density improvement that seems to be the long term trend.

This is how the numbers play out...

Year Kg $
2014 522 11000
2015 480 10230
2016 442 9514
2017 406 8848
2018 374 8229
2019 344 7653
2020 317 7117
2021 291 6619
2022 268 6155
2023 246 5725
2024 227 5324
2025 209 4951
2026 192 4605
2027 177 4282
2028 162 3982
2029 149 3704
2030 137 3444

So the REX will be lighter than the BEV even up till 2030. The cost of the REX will be lower by 2029, but as I said earlier, I think it will be down to individual owners to decide when the purchase cost is offset by gas savings. Probably by 2023 when it's less than double the cost of a battery.

This kind of supports what I was saying.. I think there's a 10 year window where EREV will sell quite well. Not to the detriment of S sales, or their planned forecast of the Model 3 Sales.

I'm actually going to answer my own question.... the EREV isn't a risk to Tesla, as there's at least 500,000 people a year who would gladly take a £30,000 200 mile range pure BEV. They will sell the lot. However... I think, “The Rest” of the manufacturers will collectively sell more EREVs than Tesla do Model 3. For a while.

I think Tesla will be here in 2030 and leading the market. Then the ICEers will start to shift their customer base to full BEV mode as the cost / weight no longer puts ICE at a disadvantage.

The question I should have asked though is “Is Tesla a risk to anyone else being able to sell cars based on ICE come 2030”. Assuming they will be ahead of the curve on cost / range, so when they finally get down into the economy sector, say early 2030s, no one will be able to shift an ICE unless you get one free in your cornflakes.

There's 1 thing nagging me though, that could mean a sooner switch... think back to 1995. How many people did you know who had mobiles? I think I probably knew 1 or 2. Ask the same in 2000, and it was most people, by 2005 it was everyone. I think – it's entirely possible when looking at leasing deals to see that the net cost of ownership with all bills added on a like for like basis. This could swing the market to BEV sooner than looking at the purchase price. It's what triggered the big mobile take up when they introduced monthly payment contracts for the new digital networks. I think this model could well work with a constantly updated technology like BEVs.

What will drive the change is more people getting EVs and friends and family getting the truth on ownership. I only know 2 people with an EV in the UK. Of 30 million cars on the road only 17,000 have been registered so far, but 25% of those in the last 3 months.

Seems like the word is getting out as more people get to see them in the metal. (or carbon).

Finally on a side note have a look at what Lotus and Jag did on the LimoGreen research project.

I guess they couldn't have forseen a 250 mile range model S with 690 hp when they did their work. However the 2 or 3 cylinder REX they developed was more powerful than the i3 REX – and lighter. 50kW and 75kg. It might appeal to some people who really fell they need to be able to continue a long drive and not have to stop for 20-30 minutes every 250 miles. I actually think that could be a small minority of people... when they compare the Free supercharger approach to sticking in 20-30 litres of unleaded. I've got a saying “you get rich by not spending money you already have”. And we haven't mentioned sub 60 second battery swaps yet. I'm assuming the demo model was a bit slow as it was designed for a production line not a battery swap station.

Anemometer | 4 november 2014

Damn the lack of edit. As soon as I hit post I realised...

School boys errors in there. Its a 50kW pack that is 137 kg in 2030 - not a 22kW pack.

So you could say by 2019 the 200 mile range from a 50kw pack would weight less (344kg) than the current 22kw weight of battery (230) + REX (120).

Again its the total 50kW battery cost. Not the upgrade from 22kW to get more range which the $3800 REX gives you. So again - by 2020 I expect to see the BEV being the main seller as 1/2 the cost of the $7,117 is getting you a lot of kWh compared to todays battery.

Unless they add a bigger tank keeping the 50/50 CARB BEVx ratio ;-)

Timo | 4 november 2014

Double the capacity you also halve the cycle rate (meaning battery lasts twice as long) and double the power, so you can use cheaper batteries with higher energy density.

That's the main problem with these city cars, they need to use expensive and heavy batteries because they don't go big enough.