GM brings back 1.0L ICE! - in the Volt plug-in series hybrid :)
 

Detroit Auto Show: It's here. GM's plug-in hybrid is the Chevy Volt Concept


https://www.blogsmithmedia.com/www.au...07cc_ch010.jpg

Of course, the achilles heel of the concept is the L-ion pack. Issues of cost and durability of nanotech versions needed to make this a feasible battery remain to be settled.

GM claims a 640 mile range on 12 gallons (US) = 53 mpg (US)

Presumably the first 40 miles are electric.

the whole concept of using an ICE as a generator for an electric motor, completely confuses me. I guess I have too much of that 'Gimme a V8' in me but it just doesn't make sense. If the ICE is at a continual 1800rpm why is there a turbo when there will be very little spool time. And would it not work just the same w/o it, or would it not create enough energy to charge the batteries w/o the turbo. Also what kinda of fe technology is put into that one litre engine. Hopefully its the same design as the one that came out of the Metro.

71bhp at 1800rpm is pretty impressive!. I guess the turbo is designed with larger vanes to spool up with, so, it can run at full boost at 1800rpm. If they then used an engine design with e.g. specially shaped pistons, and combustion chambers, they could have stoichometric or even lean burn without detonations, and a suitable cat if it is lean-burn. This would reduce pumping losses, and mechanical losses, running at high output, low revs, and
no pumping losses.

The only issue is the 53kw generator - that would be 5300 amps at 12V, or 530 amps at 120v. Could the batteries take this recharge rate?. If so, then re-gen braking would be no problem at all!

Edit : only 53mpg?

Found some more info:

https://www.latimes.com/business/la-f...home-headlines

Of course, on shorter trips, or at lower speeds, its gas MPG would be significantly higher.

I think that is exactly what the consumer needs: an EV with 40 mi range that can be extended with gas. It's pretty much a plug-in hybrid-electric veh. but maybe GM is trying to save face by calling it an "EV with ICE" since Toyota will likely beat them to market with a PHEV. Or maybe it's just another in a long line of car show teases.

Maybe a configuration like this one is the 'future' regardless who does it first. Car design would be so much more modular and quicker to market once the necesary components are available. Improvements on it might include replacing the drivetrain hardware with 4 lightweight hub motors and a maybe a diesel generator in place of the gas one. Performance cars could have ultracaps to more efficiently capture regen energy and also 'stiffen' the battery pack for high amperage launches. It's nice to dream...

From looking at that boxy shape, I bet it will need some aero 'calibration' to meet those kind of numbers at 70 mph.

At first glance, I would agree, however... It has a reasonably aerodynamic rear,
with a gentle roof slope and it looks like it has slight boat-tailing. Also, it has a small frontal area - if you look at the size of the wheels, you will see how small the windows etc are :).

Edit : also, the mirrors are raised slightly above the place of highest airflow if you
look closely!

I'm also confused by this. The little motor does make 207 lb/ft of torque, but wouldn't it be FAR more efficent if it was connected to the wheels? Then it could maintaing near W.O.T. to charge the batteries and move the vehicle until the batteries are full charged then it turns off until say 50% S.O.C.

Right now that little motor has to go through all of these reactions
(gas)chemical->
(engine) mechanical->
(generator) electrical->
(battery) chemical->
(motor) electrical->
(wheels) mechanical

that has to suck the efficeincy right out the window.

THAT is the salient issue, yes. I'll believe it when I see ... my neighbour buy one :)

Aero-wise, the most apparent mistakes are the 20 inch chunky wheels and the massive fender opening/flare to accomodate them.

Aside from the backlight angle (good) and high deck (good), the rear of the car actually sucks from a boattailing perspective because of the wheel size/style & fender flare, and the fact that the body essentially stops at the rear wheels (so no opportunity to taper past them).

On the bright side, IF this ever makes it to market, it won't come with those giant wheels. We'd see normal 15 or 16 inch ones. So they'd have the opportunity to clean up some of these issues.

And ideally, since that ICE isn't driving the wheels, it could be in the rear, so the front grille could be minimized, the underbody cleaned up, and the cooling air flow could be ejected into the wake to increase its pressure. Just like the Precept PNGV concept.

But then they'd have to engineer a torque-splitting device (transmission) that didn't infringe on Toyota's brilliant system and patents (which so far 2 other manufacturers - Ford and Nissan - have licensed, rather than try to invent their own flavour of the same thing).

I think that's one reason GM is avoiding the parallel approach. Also, it gives them much greater packaging flexibility.

Maybe ... it's a trade off. The ICE is run at 1800 rpm because that's probably where it's the most efficient in terms of hp / gallon of gas.

If you start connecting the ICE to wheels through clutches, torque converters, gears, etc., you lose a lot to mechanical friction. You also have to vary the speed of the engine and depart it's peak efficiency range for most of the time. If the average ICE-powered drive train attains the efficiency of ~15%, and if you could make the engine use gas at say 30% efficency because it stays at its best speed when in use, you'll have gained 100%. I don't now how accurate those numbers are, but Toecutter can probably straighten me out. The rest if the losses are taken from there.

Edit: ok, maybe an ICE-driven vehidle is only 12.6% efficient. :)

Also the complexity (thanks Darin) required to have the ICE do both jobs also becomes a barrier. I still can't figure out how all the modes of the Pruis work with all of its motors and planetary gears. Besides, the Prius still can't run exclusively off of the grid (as an alternate form of energy) w/o some pretty expensive mods, so it's still not complex enough. :D

ICE designs usually have to be way over-powered because the time when you need to get the most power out of the engine is when it has the least torque and is very inefficient: accelerating from a stop. At cruise, the car needs only between 5 and 20 hp to make it's way down the road depending on the car and speed. On average that 71 hp engine probably puts out twice what the car needs. That's why it only has to run half the time to keep up with the battery drain - and the ICE is off the rest of the time. Electric motors, OTOH, have their highest torque from start and so are ideal for the job of moving a car.

I figure the likelihood of exterior design changes is proportional to that packaging flexiblity ... and that's a very good thing.

The generator needs to be ~80%+ efficient. An off-the-rack model only converts mechanical to electricity at ~50% efficiency, according to most manufacturer stats, so this is crucial for vehicle efficiency. At 80% generator, 40% engine, and 72% battery/inverter/motor, we'd have ~23% vehicle, which is pretty good considering the Prius' efficiency during the EPA highway cycle is only ~20%, and this vehicle would probably have less weight/smaller CoD. :thumbup:

As others have asked, when will they build it, how much will it cost, and will it really be as "efficient" as the current "concept car"?

It's not as if this idea is exactly new. Driving wheels using electric motors, and then using fuel to power the generators has been done in the railroad industry for decades now, and it's been talked about as a possibility for normal cars for many years.

As I see it, such an approach has both plusses and minuses vs a more "traditional" design (even a "traditional hybrid design", however much of a misnomer that is), where the ICE directly drives the wheels.

Disadvantages of this design, compared to a more "traditional" design.

Since this design is so "radical" (compared to the ICE/transmission approach we have had for so long), it might take a little while for both the engineering bugs to be worked out, and for it to be built and accepted by the public. The old "chick or the egg" problem, as you ramp up to do something "new".

There are intrinsic inefficiencies with converting mechanical energy into electricity (the "generator") only to immediately convert that electricity back into mechanical work (the electric motor). And these losses are ON TOP OF the losses due to ICE efficiency (which both types of vehicles suffer).

During those times when the ICE is off you are running on batteries. But charging and discharging batteries is also not 100%, and so the charge/drain has inefficiencies in storage, in addition to the mechanical=>electric=>mechanical inefficiencies mentioned above.

And when you don't have the ICE on, you are also not generating heat. This could be a problem in the winter. I suppose you could get around this by either: A) Have a supplemental electrical heater for the passengers, and/or B) Run the ICE some when you need "waste heat". But either option is not without its costs. The supplemental heater will add some cost/complexity to the system, and will also use electricity (and electric heating isn't exactly "efficient"). And running the ICE to generating heat will obviously use some gas (although it would also generate electricity at the same time, so it's not just using gas for heat).

OTOH I also see several advantages to this approach:

It is MUCH simpler from an engineering standpoint! This (in theory) makes the design costs for such a vehicle much lower. It should also make it easier/cheaper for DIY upgrades/changes.

Such a vehicle should have less weight (and less weight does help FE) than a (plug-in) hybrid using a more "traditional" design, as you (potentially) avoid a lot of heavy mechanical parts (drive train, transmission, etc). Instead, such a vehicle will have the key sub-systems "loosely" hooked together by a combo of power cables (even very big cables are less heavy than the mechanical linkages) and electrical control signals (very light, and easy to run the wires wherever you need them).

And while there are inefficiencies in converting back and forth between mechanical energy and electricity, there are some inefficiencies in traditional transmissions/drive trains/etc as well. So the "efficiency gap" is not as big as it may at first appear, as you are really only swapping one set of inefficiencies for another (i.e. "pick your poison")...

Because you primarily using the ICE as a "generator", you can optimize the engine to run at the most FE RPMs all the time (instead of designing an engine to give decent torque when you need it). To some degree you get the same effect with a more "traditional" hybrid vehicle (where the electric engines give a decent boost), but with this sort of vehicle you can go all the way to two speed only (efficient run, and full off).

And last (but certainly not least) a vehicle based upon such a "loosely coupled" set of sub-systems really is "flexible" from an engineering/maintenance standpoint (just as the GM marketing folks are saying). The reason is, with a "traditional" vehicle most of the sub-systems are interconnected, so you can't easily upgrade one without touching another. But when you have most of your sub-systems as independent "black boxes", you should be able to easily "mix and match" as you see fit. Got a better power source? Go ahead and swap it in, and other systems (such as the electrical engines driving the wheels) shouldn't care. Ditto for improvements to power storage (better batteries), etc. Want to supplement power with solar cells? Yep that should be easy too. The point is, when you can think of a system as being made up of "independent" plugged together "black boxes", you have a lot of flexibility to improve/replace the innards of those black boxes "one at a time" while still being sure the complete system will work. So it becomes much easier to make "incremental upgrades" to the vehicle, as you can get away with working on a single "black box" (for example, to be more "energy efficient") without worry if that will break some other parts of the system. IMHO this is a HUGE advantage for both vehicle engineers and DIY types (both of which can again start working on the individual pieces as opportunity comes alone, vs having to treat the whole system at once).

I've lost count how many times I've been suckered into believing GM was finally going to come out with a great product. So far, I have always ended up feeling foolish when I realized it was just their marketeers putting lipstick on the pig again. :(

Green Car Congress has a few more details today.

According to Argonne National Laboratory, in automotive volume, Li Ion battery packs would drop to ~$250/kWh. With mass production, that achilles heel wouldn't exist any longer. This is for 18650s though, which would last about 500 cycles to 100% discharge. With 40 miles all-electric range, life would be an issue for a plug-in hybrid(while a pure EV like the Tesla, pack life > 100,000 miles). The nanobatteries could change this, but as far as I'm concerned, they'ere vaporware until we can see third party testing of an actual product.

Without Altair Nanotechnologies sort of cycle life figures, Li Ion wouldn't be very suitable for a PHEV with low all-electric range. 40 miles range * 500 cycles to 100% = 20,000 miles life. You'd really need 150+ miles range for reasonable battery life to be had on today's 18650s; with range like that, your average discharge would be lower and thus higher cycle life.

The life expectancy issue is probably why Toyota is still using NiMH for its hybrids. Li Ion is currently best suited for long range pure EVs or PHEVs with a long all-electric range.

A former GM exec essentially labels the Volt a PR greenwashing exercise:

GM has a poll on their site. 2 questions: would you want them to produce it? Would you buy one?

https://www.gm.com/company/gm_exp_liv...?navID=3.0.1.1
(Opens a Flash widget, the vote link is in top left - "Vote for Volt".)

You guys realize that if the tires are 20" tall then the roof is only about 30 inches making it about the height of a Vette - that really cuts down the aero drag frontal area. There are generators out there that are in the 90% efficiency and the battery voltage would be in the 250 - 280 volt range as that is a limit of the electronics that control the power. Using lower voltage would not make sense. Running a turbo is required because you can't naturally asperate 71hp of power burning gas through a 1 liter engine at 1800rpm - there would not be enough air flowing through it - and keeping the RPM low makes it more efficient for sure. Wish we have more definative results on the speed disk hubcaps to conclude on the mag wheels though. Funny thing is I got 50.4mpg yesterday driving back 35 miles from getting gas in my xB.

depending on the price, I'd actaully think aboutgoing to GM for a car.

Unless Toyota is still considering making a plugin version of the Prius.

The complete article with more photos of "inside" - they definately need to revamp the hood style - looks like a CTS Cadilac with some Morano fenders - need to get the guys playing with the clay some different shaping tools.

https://www.pleiades-enterprises.bigs...eneric205.html

That's funny :D

Dan at eCycle has been working on a buck/boost regulator for adding an extra lower voltage battery pack to the Prius for some guys in Canada that are converting to plugin. It looks like there is a big design hurtle to get past. The Prius monitors the Energy in and out of the battery pack instead of the actual battery SOC so that adding extra energy to the battery does not allow it to be used because the "system" thinks it is not there once the "energy" of the pack has been depleted according to its internal calculations. Prius needs to allow a bigger capacity battery setting in its software.

Plug in Prius conversion (if you have the money) - looks pretty good too!

https://www.calcars.org/priusplus.html

https://www.edrivesystems.com/faq.html

The more I look at it, the more I think GM will bring this to market. Ovonics/cobasys/GM/Texaco/etc... successfully sued Toyota/Matsu****a/etc... and the private agreement included limitations on NiMH battery size, as well what I'm guessing to be a clause for no plug-in capacity through Toyota. GM had no problems with Toyota entering the hybrid market because it's all their risk. If Toyota fails, GM loses nothing. If Toyota succeeds, GM probably has the ability to offer NiMH plug-in models while Toyota can't, and Cobasys/Co seem to be wrangling for Li-whatever rights as well. The point being, GM let Toyota develop a hybrid market via certain agreements, which may not hold to GM. Now that hybrids are most likely going to get 10-20% of market share per year, GM can roll out something that's sporty looking, has good all electric range, gets better mileage, and, most importantly, is plug-in for about the same price as a Prius. Effectively, GM can source better, cheaper NiMH batteries than Toyota because the same contractual constraints do not apply to them, and by nature of their hybrid design, they must do bulk business. I'm thinking we'll see this available to combat the next gen Prius. Given what GM has done with Daewoo, this is very likely imo...

Stop dreaming. This is Gm we're talking about. There's a reason for the specs seeming to be amazing and the public only having a drawing of it. It's just PR bull**** to try to attract people back to GM after a 12% drop in GM sales this year.

Believe it or not, they actually made a concept car, and it even appeared to move under its own power on a stage at the unveiling (unless the stage was on a slope :)).

https://www.gm.com/company/gm_exp_liv...dex_flash.html

Launches a Flash page. Click into the Volt, then "webcasts" on the bottom, then "click here to view" above - it's vid of the unveiling, with a hokey bit at the start about monumental achievements in history.

The car appears about half way through, after Lutz talks.

Of course for wall we know, it's just another parlor trick involving a re-skinned Cobalt chassis driven by the motor from an electric forklift. :D

Now THAT would be a car I'd buy!

I'll believe it when I see it driving down the street. For now, it's probably just another GM gimmick to try to convince us that they care about more than their profits.

I really wonder how effcient that gas engine is, I meen if you have an engine that is going to run at a single speed, you can design the whole thing to run more efficently, you can tune the air intake to that exact engine speed, you can do away with the butterfly in the throttle body and run it "wide open" by having the throttle body the exact size you need it to run at 1,800rpm, tune your exaust for that same engine speed, your power band would be extreamly narrow, you might even have to have the generator act as an electric motor to get the gas engine up to it's full speed, because it might not run correctly at lower or higher speeds, but at that set speed, in theory you could make it run above the 23% effeticy that SAE clames a gas engine in a car can be, oh yeah, then add the turbo for more effecitcy, I rather like this idea, of course that might just be because it's very simaler to my electric bicycle idea, small gas engine running an alternator, with a lith-ion battery buffer that is good for a few miles, and a wheel hub motor... with luck after a few more pay checks I'll start buying parts.

It really depends. GM is very profit driven, so in the case of Daewoo, instead of developing their own small car, with the risks and cost, they pulled the rug out under an established car maker, and used the threat of a long legal battle to work out a deal that was good for them, while still being o.k. for Daewoo, even though Daewoo probably would've had it better with their own operation in America. In the past they had bought small cars from other companies like Toyota (Prizm=Corolla) to boost fleet reliability/FE ratings, but it was expensive, and the Daewoo move was a coup of sorts. I think the same applies to hybrids. Let Toyota pave the way, and introduce their own version when there's minimal risk and assured demand. The confidential agreement probably has provisions that make this a relatively risk free deal for GM. They are after all, the most profit driven, so if they can carve out an assured 25-50% of the small car hybrid market, I don't think they would pass that up.

So not only did they 'borrow' your idea, but I think they've been using that very same kind of fiscal management. :D

I was watching some of the theatrical antics with the Hollywood stars. My favorite spur of the moment line is when Jimmy Kimmel was talking to Cheryl Hines about when she was 15 and learning to drive. Mentioning the the guy who taught her to drive, she said "he had this little Triumph..." Jimmy chimed in and said "I bet he did." :D

Hey! it was an option of either buying a 33cc micro 4 stroke honda gas engine, or joining the rest of the people in the 21st century who have electronics with lithum batterys (cell phones, lap tops, digital cameras) so I bought a cordless drill, my fiscal management is much better then GM's.

Yes, I'm with you on that. Just so you know, the joke is about them.

Volt in suburbia...

https://video.google.com/videoplay?do...5&q=chevy+volt

Sounds like it has a forklift motor (maybe that's why they won't amp it up in the video) ;)

Not to mention that Li-Ion only lasts a couple of years from the date of manufacture, at least in my experience.

WOW did they have any more gears to get going any faster?? What that must have been 10 mph top speed? I was surprised that it was able to back up the driveway.