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Discussion Starter · #1 ·
With the introduction of the C-Max Energi, there has been lots of speculation about how GM should respond. This includes moving Voltec to larger platforms (e.g. Equinox, Malibu, even Imapla). But can Voltec, as we know it in the Volt, be scaled up to run on far heavier platforms? With the current state of battery technology, I have my doubts. (Disclaimer: I am decidedly non-technical when it comes to EV & hybrid technologies.)

But is Voltec flexible enough to be programmed more like a plug-in hybrid rather than an EREV? Might it be more scalable as a plug-in hybrid? Perhaps as a plug-in hybrid a smaller battery would be used. A more efficient, more powerful ICE would most definitely be required. In this configuration, the ICE would be much more actively used to propel the car. Pure EV mode would still be there, but much more limited ala C-Max. With Voltec, the car could also run as a series or as a parallel hybrid depending upon the demands of the moment. Might the flexibility of multiple hybrid modes actually make such a car more efficient than the C-Max/Fusion plug-ins? Do you think that the ELR might take a first step in this direction of more aggressively using the ICE?

I repeat that I am a non-technical person, but I do hope that Voltec is flexible enough to do this in a cost effective and efficient manner. I think it would be terrific if Voltec supported both EREV and plug-in hybrid applications. (It's also quite possible that I don't know what I am talking about. lol)
 

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Hi Eric,
Yes Voltec is very flexible. You must be new to the world of EREV. There is a company called VIA which upsets every GM Voltec fan. For a hefty price they will take a GM Silverado, Suburban or Van and make it an EREV.
Below is a video of Jay Leno taking a test drive.
http://www.youtube.com/watch?v=p5STy6HRZEQ&feature=player_embedded

VIA Motor Company website.
http://www.viamotors.com/lineup/

Of course GM could be doing this themselves at less cost to the consumer but the bright minds at GM aren’t keen on built to order. To them, if they can’t roll out thousands at a time it’s not cost efficient.
IMO, GM needs a built to order division. They should buy VIA and make it their B.T.O. Voltec division.
 

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The existing Voltec system, as implemented in the Volt, cannot be used in the "gas+electric" fashion that the other plug in hybrids operate - the gas engine and MG A can't match the troque produced by MG B (they're fighting against 2.45:1 gearing and are both weaker to begin with,) and so trying to mesh the engine in would only result in a slower car.

HOWEVER, part of the reason that the Volt got off the ground as quickly as it did (29 months from production decision, and yet they delivered a polished, reliable car!) was that they built the drive train off a slightly modified version of the unreleased FWD 2-Mode hybrid version, which gave them productionized tooling and a lot of the pieces. (In the 2-mode, both MGs are 55kW, there's an extra gear set and another clutch or two.)

If GM decides that they need to fight the PiP or the Energi twins on their own terms in the market below the Volt, there is absolutely nothing preventing them from resurrecting the FWD 2-mode transmisson, marrying it to an Atkinson version of the 2.0 DI engine (presumably without the turbo,) and dropping it into a Cruze and Equinox platform with a smaller battery pack. Depending on how the details work, that would pretty much be a GM Energi, with the potential benefits of being a 2 mode car instead of an HSD car (in a passenger car, the main one is somewhat better efficiency in freeway cruise.) There was some talk last year from a GM executive announcing there would be a Cruze PHEV 2-mode coming, which was later explained away as a misunderstanding. I guess we'll see.

The natural way to build a parts bin Voltec CUV/SUV is to combine the Spark's larger capacity under the rear floor battery pack with the existing Voltec package and add a rear axle motor (notionally, something like the Highlander Hybrid/RX450 50kW air cooled package. If I have to stay pure announced GM parts bin, the complete Spark drivetrain, with the 83 kW motor would certainly work (though whether the battery pack could handle the full 200 kW to take best advantage is questionable.)) The same Atkinson 2.0 DI would be welcome here, but under most conditions the existing engine could work fine, or they could adopt the turbo from the Cruze again.

Buick is a logical place to host this car, since they already have the Volt, Spark, and ELR out there and Buick has been building a CUV line up/reputation lately.

Note: I am an engineer and enjoy speculating about these things, but I'm making the SUV up out of whole cloth. GM has to know it's a market they want soon, but since the MPV5 toured Asia a year ago, nothing has been said. I guess we'll see.
 

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I would say that the concept is scaleable to any size you want, even an 18-wheeler. But in order to keep 0-60 performance tolerable they'd most likely need to design a new, larger transaxle for an SUV or pickup. I believe the electric motors are contained within the transaxle, just like the Prius. The batteries also can be scaled up. But one thing is for sure. It is no coincidence that most of the hybrids and electric vehicles have been small cars. Obviously when you get to a larger vehicle you are going to need a larger battery. And that is going to add a lot more cost. As far as profits are concerned, this works opposite to the auto manufacturers' current paradigm. The way I understand it, it really doesn't cost much more to build a big truck or SUV than it does to build a small car. But for some reason they can charge a lot more money and people will pay it, giving them hefty profit margins. In the case of an electric or PHEV pickup or SUV, I believe the opposite would be true being that it really does cost more to make one.
 

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My opinion is a business one not an engineering one. When the feds bailed out GM, I think GM promised high sales for the Volt such that it will cover its development/sunk costs in the third year of production (60k/year), after that the Volt will be a cash cow. That was overly optimistic, it seems the Volt will recover all the investment in the fifth or the sixth year of of production (assuming GM makes 10k/car in profits, a 33% markup which is fair for novel technology and it line with what Lutz said in a recent article). The question now is would GM double down on the Voltec platform and invest in more vehicle beyond the ELR? Should it wait for the Volt/ELR to cover its costs and allow the technology to mature more or should it take the plunge. I would understand if GM decided to wait, they put out an excellent product and they got bashed for a few years for it, what if the next offering didn't live up to the Volt?
I think the challenge for GM is a business one not an engineering one.
 

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Go down to the railroad tracks. That big black thing on the front of the train is a diesel engine driving a generator driving electric motors. They dispensed with the battery. When you are in Mountain Mode its ok to make train noises.
 

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Discussion Starter · #7 · (Edited)
...but since the MPV5 toured Asia a year ago, nothing has been said. I guess we'll see.
Well I new nothing of the MPV5 before your post. And all I can say is WOW! I love it. I'd take it over the C-Max any day of the week. And despite the T-shaped battery, they did manage a bench rear seat and a 5 passenger capacity. (It's just a concept, so maybe some wishful thinking capacity-wise.) I wonder why this little gem never made an appearance on the U.S. auto show circuit.

I suppose that the seasoned members of this forum are familiar with this concept. But if you haven't seen it, here is a link to an article with an nice photo gallery:

http://www.caranddriver.com/news/chevrolet-volt-mpv5-electric-concept-car-news

Edit: Something just struck me about the showing of this MPV5 concept in Beijing (see photos). Its not on a turntable or in a roped off area. It is just sitting there on the show floor and the public has full access to it -- opening its doors, sitting in it, and such. Seems like it must be more real than your typical concept.
 

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That would work...a lot of BMW X3 influence. I am surprised it was shown as a Chevy in China....not Buick. But that was some time ago.
 
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