By on October 11, 2010

As GM finally begins to let journalists drive its Chevy Volt, the two-year-long trickle of bad news about the project is turning into a raging torrent. The latest bit of bashing: InsideLine claims that, in direct contradiction to GM’s hype, the Volt is in fact powered by its gasoline engine under certain circumstances.

At the heart of the Volt is the “Voltec” propulsion system and the heart of Voltec is the “4ET50″ electric drive unit that contains a pair of electric motors and a “multi-mode transaxle with continuously variable capacity.” This is how GM describes it:

“Unlike a conventional powertrain, there are no step gears within the unit, and no direct mechanical linkage from the engine, through the drive unit to the wheels.”

The 4ET50 is, however, in fact directly bolted to the 1.4-liter, four-cylinder Ecotec internal combustion engine. When the Volt’s lithium-ion battery pack runs down, clutches in the 4ET50 engage and the Ecotec engine is lashed to the generator to produce the electric power necessary to drive the car. However under certain circumstances — speeds near or above 70 mph — in fact the engine will directly drive the front wheels in conjunction with the electric motors.

As in the Prius, the Volt’s drivetrain includes a planetary gear set that acts as a transmission. The intricacies of planetary gears are many, but in rough terms each element (electric engines and internal combustion engine) of the Prius or Volt drivetrains are hooked up to different elements of the gear set. In the Volt, its Ecotec engine is clutched to the outer ring gear and as the car’s speed reaches the edge of efficiency for the electric motor, that ring is set from its normally rigid mounting in the 4ET50′s case and allowed to spin. That has the Ecotec driving the front wheels.

The Volt’s Vehicle Line Engineer Doug Park confirmed that there is, on occasion, a direct mechanical connection between the internal combustion engine and drive wheels in an interview with Norman Mayersohn of The New York Times. This isn’t idle speculation or educated inference, it’s an admitted fact.

It doesn’t take much work to discover that GM has directly concealed this reality from the public, by stating repeatedly that the Volt is powered by electricity at all times. GM even “corrected” reports that it was “considering” allowing the Volt (or its sister car, the Opel Ampera) to drive under gas power under certain circumstances. And its most recent press release calls Voltec a “pure electric” drivetrain with a gas range extender. The last thing GM needs going into its Volt launch is a credibility gap in its explanations of the Volt’s convoluted internals.

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69 Comments on “Inside Line: GM Lied, Volt Uses ICE For Propulsion...”


  • avatar

    I’m not nearly offended by this particular lie as much as others told by Government Motors when talking (out their a$$es) about the Volt. What offends me most is how egregiously the Volt actually performs in real-world conditions relative to its moonshot pricetag.

    Then again, we should all be used to Government Motors spinning the truth by now. Anyone foolish enough to buy one of these will be getting just what they deserve, I’m sure.

  • avatar
    dougw

    Call me stupid or worse, but somehow I am still excited about being able to do my typical 20 mile commute every day with NO gas used.  I am also excited about driving to town 30 miles away using gas in only one direction.  
      
    If the drivetrain goes into lockup with the gas engine for speeds higher than 70mph what do I care? If it didn’t there would probably be criticism about spongy speed control at the upper end. For my use 99% of my driving will be less than 70mph, so again no bother.

    I understand the technical curiosity about the Volt but I am a bit mystified by the strident and continual “gotcha” stuff.

    Let’s just wait and see how the target demographic feels about the car.  We’re all in this together and the less crude oil we have to prostitute ourselves for the better.

    • 0 avatar
      KixStart

      Save yourself $8K or so… get a Leaf.  It will handle the 60 miles.

    • 0 avatar
      nonce


      I understand the technical curiosity about the Volt but I am a bit mystified by the strident and continual “gotcha” stuff.
      We are like grammar nazis, only more anal.

    • 0 avatar
      hreardon

      dougw -

      It’s neat, but not at an $8,000 – $10,000 premium over other vehicles which get between 25 – 35 mpg with far less complexity (Sonata, Golf TDI, GTI, Accent/Elantra, Civic, Versa, etc.).

      If the raison d’etrat of the Volt is America’s first real mass produced “electric car” I think that most people will be sorely disappointed.

      The target demographic will be early adopters, environmentalists and techies.  They’ll pay the premium and love the attention.

    • 0 avatar
      gslippy

      I understand the technical curiosity about the Volt but I am a bit mystified by the strident and continual “gotcha” stuff.
       
      The Volt is supposed to be representative of the “new GM”, but this issue is classic “old GM”.
       
      Let’s just wait and see how the target demographic feels about the car.
       
      I suspect the target demographic is already sold on it – greenies who don’t really care what it costs to divorce from oil, or techies who just want the latest gizmo.  But as KixStart points out, the Leaf will give you both at a lower price.

    • 0 avatar
      HoldenSSVSE

      @KixStart

      Nissan’s own testing has shown that in moderate heat (86 degrees) and stop and go traffic (you know a normal day in LA) that the Leaf’s range drops to around 45 miles.  The only electric that is coming close to delivering on its range promises is the $109K Tesla Roadster, which is utterly impractical for 99.9% of drivers/commuters and out of reach for most buyers.

  • avatar
    Cammy Corrigan

    “Ampera”, Ed. Not “Ampara”. “Ampara” is a city in Sri Lanka.
     
    As for the Volt allegation, if that is proven beyond reasonable doubt, then the Volt is nothing more than a Prius (with worse fuel economy figures). Which will annoy Bob Lutz, that little bit more…

    • 0 avatar
      hreardon

      Cammy – and the Prius is ultimately the vehicle the Volt will be compared to.  

      Volt is being hyped for its fuel savings and miles per gallon rating.  When the results start showing that most people aren’t getting anywhere near the advertised figures, the damage will be done and Prius sales will continue unabated.

       

    • 0 avatar
      charly

      Isn’t 65 the maximum speed. As such one could argue that it will never under legal circumstance drive the wheels directly

    • 0 avatar
      Matthew Sullivan

      Isn’t 65 the maximum speed.

      No.
      http://www.houstonfreeways.com/modern/2007-01-07_80mph_west_texas.aspx

  • avatar
    carve

    Well, direct drive is actually a good thing.  I’m glad it can work that way- much more efficient.  However, if it can do this, WHY THE HELL IS THERE A SEPERATE GENERATOR!?  That’s a major added expense and complication.  Let the motor act as a generator to soak up some engine power when there is a surplus, and let it augment engine power when there is a deficit…just like any other hybrid.  This would reduce cost and weight and improve efficiency.

    • 0 avatar
      Paul Niedermeyer

      The Toyota HSD uses two electric motor/generators too. It’s pretty much essential for a full hybrid setup.

    • 0 avatar
      nonce

      Yes, we complained about the gas -> engine -> battery -> motor wheels thing, because that’s what they were doing.
       
      Now that we find otu they might be doing it better, we must complain about them doing it better.

    • 0 avatar
      SVX pearlie

      Exactly. God forbid that GM use the most fuel-efficient options at their disposal.

    • 0 avatar
      psarhjinian

      I agree.  Weren’t we just complaining, a few articles ago, about GM not directly connecting the ICE to the wheels as the Prius does?  And now they are doing it and it’s a bad thing?
       
      Look, I know the car was a Hail Mary before bankruptcy and a thorn in the shoe of tax-hating libertarians after the bail-out, but can we stick to disliking the car for legitimate reasons (eg, the EV range appears to be below promise, the styling is anodyne at best and the interior ergonomics are textbook case of how not to do it) instead of deriving new reasons that aren’t really applicable?

    • 0 avatar
      niky

      I’m on the “Thank God they did the reasonable thing” bandwagon… and i fully suspect that the direct drive is the reason for the Volt’s more than reasonable 38 mpg highway versus its dreadful 33 mpg in the city.
       
      of course… that still opens up the problem of direct comparisons to the Plug-in Prius… which is basically a Volt with shorter battery range, better battery-depleted performance, a bigger trunk and a lower price tag.
       
      In fact… does the Volt even QUALIFY for the EV tax break since it’s essentially just a plug-in hybrid and NOT an extended-range EV? That’s the big conceit.

  • avatar
    segfault

    So it’s a plug-in hybrid, not a range-extended electric vehicle.  I bet Toyota’s plug-in hybrid Prius gets more than 32 MPG when it’s released.

    • 0 avatar
      Paul Niedermeyer

      There are numerous long-term tests of the plug-in Prius by various magazines. 65-85 mpg is they range that they’ve been seeing.

    • 0 avatar
      L'avventura

      On a pure depleted electric charge the Prius should do worse then the current Prius being that it weighs more due to the increased battery weight.  The efficiency hit will depend on how much more the 5.2kwh li ion battery weighs over the 1.8 Kwh NiMh battery.
      However, Toyota’s approach has been upfront from the very beginning.  That the plug-in feature will be designed to increase mileage of the Prius, not be an EV with range-extender.  So overall mileage should be much higher.
      What is surprising however is the claim that the Volt has the gas engine kick in when the speeds approach 70 mph.  The PHV Prius’ greatest short-coming is the 65 mph EV limit.
      So the Volt basically just is a hybrid-Cruze with a heavy 16 kwh battery.  At over 3,700lbs, the Volt weighs 900 lbs more then a Cruze and as much as a Chevy Equinox.
      Oddly the Volt seems to be technically in the middle of the PHV Prius (smaller-battery PHV) and the pure-EV Nissan Leaf.
       
      The real question becomes what Toyota decides to sell the PHV Prius at.  The PHV Prius should only quality for around $2k of subsidies since its calculated by battery size (the Volt gets $7.5k), but the Prius should cost a LOT less to build.  If Toyota sells the PHV Prius for $35k its a huge-win for GM, if its below $30k the Volt would look way overpriced.

    • 0 avatar
      Facebook User

      I think more than anything the Volt has made me appreciate what the Prius has been doign for years. The no compromise vehicle(in terms of usability), and affordable price and impressive mpg.
       
      why on earth does the Volt get such bad economy in gas only mode?
       
      how was the 65-85 mileage ratings measured?

    • 0 avatar
      psarhjinian

      why on earth does the Volt get such bad economy in gas only mode?

      Two reasons:

      One, probably because direct-drive is seldom used.  It sounds like it’s only an option under certain conditions (eg, steady-state, light-load cruise) and otherwise it’s operating in genset mode.

      Two, because it’s a heavy car with a small motor that’s being run hard.

  • avatar
    gslippy

    There was a certain elegance to decoupling the mechanical propulsion from the electricity generation.  Now it’s even more complicated than anyone imagined.
     
    I am Volt weary from all the hype, but GM’s steady misinformation campaign about this feature is troubling.  More importantly, couldn’t this affect the Volt’s EPA classification as an EV?

    • 0 avatar
      SVX pearlie

      Actually, the way it’s described, it’s pretty elegant, because it sounds like the gas motor does a 1:1 direct drive without any mechanical transmission step-up/step-down gears.

  • avatar
    twotone

    reVOLTing!

  • avatar
    KixStart

    So GM lied about unimportant technicalities on an extremely low-volume car that everybody expects to lose money for years anyway (including Maximum Bob).  A truly pointless lie.

    So… one wonders… will they tell the truth when the chips are down on something important?

  • avatar
    obbop

    I will refrain from any A/C D/C jokes.
    I will refrain from any A/C D/C jokes.
    I will refrain from any A/C D/C jokes.
    Slinks back to the shanty before a bevy of tossed boulders bounce off my delicate old coot body.

  • avatar
    Rod Panhard

    Now that we know what we suspected all along, one has to wonder…Did GM choose to release the car on the eco-weenies of California, New Jersey, New York first because they’re so gullible they’ll believe anything told to them when they wear their green-tinted glasses?

    • 0 avatar
      Zackman

      Not at all – that’s just where all the ancient hippies live and still believe in their shallow, save-the-planet mis-guided lifestyle!

    • 0 avatar
      Dr Lemming

      Desperate corporate management with their backs against the wall will tend to try every trick in the book.  Will it work with us enviros?  Probably not so well, particularly if trend setters such as Consumer Reports get grumpy.
       
      BTW, some of us “green weenies” read TTAC. Might do so more often if the level of civility were higher.
       
       

    • 0 avatar
      jkross22

      Zackman,
       
      The ancient hippies I’ve met are full of piss and vinegar and some of the most angry, vulgar people you’d have the displeasure of meeting.  They are mean as snakes.  Proof source:  People that live in Topanga Canyon.

    • 0 avatar
      zbnutcase

      jkross22, are you just NOW figuring out the “party of tolerance” is anything but?? Eco-weenies have done nothing but destroy jobs and industry, and its their way or the highway. THEY CAN ALL GO TO HE@@! And take their phuktard hybrids with them.

    • 0 avatar
      psarhjinian

      This car was built for the same reasons that GM built any number of concepts prior to the Volt, “green” or not:
       
      One, to make it look like the good stuff was just beyond the horizon.  It gives the fanbase hope and the media some wankery while distracting from the mediocre production cars being ground out.
       
      Two, to keep people from committing to the competition.  GM knows that, as soon as a customer signs for a Prius, they’ll never darken a GM showroom again
       
      The problem with the Volt is that, while they didn’t really intend to build it any more than they intended to built the Sequel, Hywire, Banshee, or any number of concepts, they were caught in the limelight with a product that was exactly right for the time and market.  They were more or less forced to build it, and bankruptcy and the bailout only made it worse.
       
      This wasn’t the “eco-weenies’” fault: it was GM’s own standard operating procedure backfiring on them.

    • 0 avatar
      musiccitymafia

      +1

    • 0 avatar
      Mike999

      - It was Wall Street Fraud in the mortgage market that destroyed this economy
      - Wall Street that started the, for no good reason, outsourcing of American Jobs
      - The Oil and Coal industry that will not allow Americans to get off oil
      - The Koch brothers and crackpot Murdoch that started a Propaganda industry in this country
      - And the “US” chamber of commerce taking Foreign Money to back the Minority Party: Republican, and the even smaller Nutcase core: Tea Party.
      - It’s the Flag Waving “Right”, that kisses Wall Street rear, that’s destroying this country.

      - Republicans don’t have the B***’s to go against Big Business Ripping US off.

      Why am I replying to someone with “nutcase” in his id?

  • avatar
    Daanii2

    Reading the Edmonds InsideLine article carefully, I think they are making a mountain out of a molehill. As is TTAC. This is a minor issue, in my opinion.

  • avatar

    I was told by someone at one of the Federal laboratories that works on this sort of stuff that the Volt is more of a hybrid than GM is letting on, so this doesn’t surprise me a bit.

  • avatar
    nonce

    I hear the ball bearing inside the car are painted white, not black like someone suggested.  FRAUD!

    • 0 avatar
      rpn453

      Hearing that ball bearings are painted would certainly be cause for concern.  If you’re metaphorically saying they’re doing it wrong either way, I’ll agree!

  • avatar

    Might as well wait for a pure EV, then.
    Fiat 500 EV, here I come… unless Ford offers their Focus EV in the 5-door hatch body…

  • avatar
    Toyondai92

    Yawn, GM lied, and their products don’t/won’t meet expectations. That’s what keeps my generation geared to other makes, and what will always keep them there.
     
    Nothing to see here, move along…

  • avatar
    John Horner

    Now I’m really stumped. Why doesn’t the Volt get decent fuel economy in gas powered mode?

    • 0 avatar
      majo8

      Weight.

    • 0 avatar
      L'avventura

      …because it weighs over 3,700 lbs. ~700 lbs more then a Prius.
      But considering it weighs as much as a CUV, such as the Chevy’s own Equinox, the Volt’s 30mpg+ in mix-real-world conditions I would say is fairly impressive for a car of that weight.

    • 0 avatar
      gslippy

      Too much car to pull with too little engine.  The Volt is on the bad side of the efficiency curve when in ICE mode.  The engine is probably optimized for electricity generation, not direct propulsion.  That’s what you buy a Sonata or Cruze for.
       
      @ L’avventura: A mid-sized Buick can hit low 30s on the road.  For the Volt to do this is no great accomplishment.
       
      GM will have a rough time selling the Volt in the same showroom as the Cruze, at least to anyone who can do math.

    • 0 avatar
      niky

      It’s not merely weight. It’s because at low speeds, the generator still has to drive the electric engines. Engine lock-up to the planetary transmission occurs at a much higher speed than in the Prius… if the engine were set to engage at a much lower speed at a lower ratio (the Prius runs on gasoline at high speeds, but because it’s set to run the gas engine at lower speeds, top speed is mediocre), it would be more efficient.

  • avatar
    dougw

    I just have to ask of those of you who are saying that this is nothing more than a Prius, or the Leaf is 8K less, and such:

    Which of those will allow me to drive all month around and about my locale, including to work and back every day….without buying gas-not a Prius, not a TDI (I own one), maybe the Leaf, but  then…..

    Drive to the big city a hundred miles away and back with the same car, still getting siginificantly good mileage.  Not the Leaf…range limit.

    It just seems that few people are acknowledging the entire package of possibilites presented in this one car is not matched by any competitors.   I suppose you would buy a Leaf and a TDI and say it is better that way.

    Put another way….Ya’ll are craziern Hell!

    • 0 avatar
      nonce

      $8,000 or $9,000 is a big premium to pay for a gas tank.
       
      I prefer the Leaf over the Volt, although I think they will both find their niche and sell out in the first year.
       
      I also wish the Leaf had a small gas engine, for heat and emergencies. But I can probably add one myself for much cheaper than $8,000.

  • avatar
    oboylepr

    GM Lied, did they?
    I’m shocked, stunned, gobsmacked and betrayed! Makes you wonder about the IPO.
    The new GM = The old GM.
    This VOLT debacle is going viral!

  • avatar
    Ion

    I kinda suspected something was up when they let it slip the Volt would have an 8 gallon gas tank instead of the initially planned 1 gallon.

  • avatar
    Jerome10

    Are you guys serious?  This is a big deal?  The mountain from a molehill comment is exactly right.
    At the end of the day, the Volt drives in all-electric mode for approx 40 miles, then it uses a gasoline engine for any distances greater than this.  It sill allows most people to never use fuel, as promised.  It still doesn’t leave you stranded, needing a charge, as promised.
    I just cannot see why everyone is getting their panties all bunched up over this.  And especially if this setup improves overall efficiency.  They’d be dumb not to have done it.
     
    I don’t get this at all….

  • avatar
    Doc

    The main issue here is that this technology is not ready for prime time. It is very expensive and does not work real well yet. It may never work. Electric cars are not the product of market demand as much as they are a product of government demand. Driven by subsidies and mandates.
    In fact other methods of increasing fuel efficiency and decreasing emissions that might work better are being crowded out by the governments heavy handed pushing of electric cars.

  • avatar
    panzerfaust

    Its a big deal because GM hyped the Volt to the Nth degree. If all the Volt was going to be was a Cruze Hybrid, no one would be squalking right now. Range and performance figures are turning out to be less than expected, and these are expectations that GM fostered.  It will be interesting (and possibly embarrasing) to compare the Volt and the Cruze’s range, mileage and price-or for that matter compare the Volt with any of the other economy cars that GM is selling.  They have a bad habit of packaging their models but not paying attention to the prices, and so a loaded Malibu costs as much or more as an equally equipped Impala, a Cobalt SS is priced near the same as a base Camero. And finally, after all this PR sturm und drang, the GM hasn’t brought anything to the table that we couldn’t get from the local Toyota dealer for the past 10 years.  Perhaps people will buy it for the image factor, but how many units is that?

    Maybe they should just call it the Vega II and move on to something else.

    • 0 avatar
      Steven02

      It is amazing that you manage to get the Impala, Malibu, Cobalt and “Camero” into this debate.  But is obvious you don’t understand how car pricing works.  Did you know that a loaded Corolla costs more than a base Camry?
       
      GM made the right move here.  The vehicle is more efficient this way.

  • avatar
    ktm

    I suggest that people such as psarhjinian actually read the links from the article and then re-read what Ed is stating.  I will spell it out for you:  he is not “complaining” that the ICE drives the wheels in extended range mode.  I will say it again - he is not “complaining” that the ICE drives the wheels in extended range mode.
     
    GM, stated from the very link most recent press release (note – you have to click it from the article) that “Power is inverted from a technically advanced, 1.4L 63-kW (84-hp) gasoline-powered onboard engine to the electric drive unit to provide up to 310 additional miles of range.”
    Ed’s point is that GM has been hyping this car as being driven by electricity alone (regardless of the source of the electricity), when, in fact, the ICE drives the car in certain modes.  Is this in itself a bad thing?  No one is saying as much and I challenge you to point out where he says so in the article.
     

    • 0 avatar
      Daanii2

      Edward Niedermeyer’s headline says “GM Lied.” That’s pretty strong. It appears from what people have discovered that the gasoline engine contributes to propulsion at higher speeds. Why? That gives greater efficiency.
       
      Where’s the big lie? It’s not like GM is trying to pass off the Volt as just a gasoline car disguised as an electric car. And the Volt’s quite different from the Prius. Performance might not be that different, but architecture is.
       
      Sure, criticize GM for hyping the Volt too much when it may not be warranted. That’s fair. Even that, though, may not be warranted. In this case, I think TTAC’s hype is worse than GM’s hype. Doesn’t GM have the right to change its mind? Without being accused of lying for making what seems to be an engineering change worth making.

  • avatar
    musiccitymafia

    Not saying it matters …. but did GM develop this little trick themselves?

  • avatar
    MadHungarian

    The limitations of the Volt and the Leaf only go to show how good the Gen2 EV1 (with NiMH batteries) was.  I’m trying hard not to get all Michael Moore about this, but I have to think that if GM had spent the past 16 years developing and refining the EV1 instead of walking away from the project, they would have a pure EV with better range than the Leaf, and could have developed a larger vehicle, a crossover maybe, with a Volt type range extender, off the same platform.

    • 0 avatar
      Daanii2

      What might the EV-1 have become? That is an indeed interesting thing to think about.
       
      I blame the California Air Resources Board for GM abandoning the EV-1. And for all the other carmakers abandoning electric cars. GM (rather unusually) led the way to electrics by developing the Impact (later EV-1).
       
      The Board saw what GM was doing, liked it, and mandated that a certain percentage of the cars sold in California be electric. The carmakers went to court to kill that mandate. After that, they would not be caught dead promoting an electric car.
       
      The California Air Resources Board killed the goose that laid the golden egg, well before it could lay all but that first one. Too bad.

  • avatar

    This is why it’s a big deal that Government Motors lied about the Volt. Recommended reading… posted by a GM fan:
     
    http://www.gminsidenews.com/forums/f13/edmunds-gm-lied-chevy-volt-not-true-ev-96429/index4.html#post2172166
     
    Highlights:
     
    -GM has lied about the Volt before. Timeline, styling, mileage, now propulsion.
     
    -GM has utterly failed to market the Volt properly (Volt Dancers, anyone?)
     
    -GM has zero credibility with the majority of the US carbuying public, thanks to 30+ years of shitty cars and promises of something better ‘someday’.
     
    -While this all has (perhaps correctly) been blown out of proportion, it’s still GM’s fault for what amounts to an incompetent and/or misleading string of misinformation about the Volt.

  • avatar
    Mike Kelley

    Here’s a good article about the “green jobs” myth in California:  http://spectator.org/archives/2010/10/11/californias-green-nightmare

  • avatar
    FleetofWheel

    A big corporation lies to hide the fact that it’s key green technology is not so green and GM gets cover from the left?
    Seems strange until you realize how much the market meddlers have riding on this grand experiment in industrial planning that we know as Government Motors, Mark of Fairness.

  • avatar
    rudiger

    The more details that come out about the Volt, the more it seems like it’s definitely not an EV but a hybrid that simply depends on its batteries more than any hybrid that’s been built to date. I never really bought into the line that the electric motor always powers the wheels and the ICE simply powered the generator to either charge the batteries or power the electric motor directly.

    In certain high-demand circumstances, whether it be at high speed or traveling over a long distance, I can sure see the electric motor running out of steam (even with the 1.4L charging for all its worth) and the ECM switching over to the 1.4L ICE for direct propulsion. It just makes sense as a back-up and, frankly, I wouldn’t want it any other way.

    Or, looked at from another perspective, the Prius’ ICE kicks in at about 15 mph. In the Volt, it doesn’t do it until 70 mph.

  • avatar
    Daanii2

    I’m confused. Did GM “launch” the Chevrolet Volt yet? I saw a Detroit News article that suggested that it did that yesterday, on 10/10/10.

  • avatar
    Greg Locock

    One other area of some interest is the Cd of the production vehicle. Initially there was a bold claim of better than 0.26, but later Lutz said 0.27-0.28 in production. I guess the EPA certification is where we’ll find out.

    The car’s weight also seems a bit on the portly side, about 1.7 tons. Admittedly the battery is a direct contributor to that, even so, the poor old Daewoo bodyshell must be creaking a bit.

    So between the weight, and the aero, early reports of a combined mileage of say 36 mpg  on Premium don’t look too surprising.  

  • avatar

    At the heart of the Volt is the “Voltec” propulsion system and the heart of Voltec is the “4ET50″ electric drive unit that contains a pair of electric motors and a “multi-mode transaxle with continuously variable capacity.”
     
    It sounds to me like GM kick started the development of the Volt by using technology from their quasi-stillborn two-mode hybrid system, basically an advanced THM with a couple of electric motors built into it that allow a large range of gear ratios and torque loads. Since those motors can operate in genset mode when recovering energy from braking, my guess is that GM decided to adapt the two-mode hybrid to use one of the motors for driving the car and the other for generating electricity.

  • avatar
    Daanii2

    The “GM Lied” headline piqued my interest. So I looked into this a little more. Yesterday’s Motor Trend article on the Volt system is pretty good. It is at:
    http://www.motortrend.com/roadtests/alternative/1010_2011_chevrolet_volt_test/index.html
     
    Electric motors do have problems at high speeds, when torque tails off. Gearing is important, as Tesla Motors found out with its Roadster. The two-gear transmission Magna designed for them did not work, and Tesla had to get creative with their gearing to get the higher speeds it had promised its drivers.
     
    GM has, in much the same way, used creative gearing to get around the problem of high-speed torque tail-off. Did GM thereby spoil the purity of their architecture? Can they no longer claim that the Volt is a virgin electric vehicle? Or has the Volt been spoiled by a mating between the transmission and (shudder) the gasoline engine?
     
    In my opinion, the Volt is still virgin. But I can see how other people might disagree. After all, I’ve always thought that oral sex was still sex. But the President of the United States disagreed, quite publicly, with that. From what I heard, many teenage “virgins” also thought the same way.
     
    I still think TTAC is being puritan about something that matters little. Still, many seem to agree with you. To each his own.


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  • Authors

  • Brendan McAleer, Canada
  • Marcelo De Vasconcellos, Brazil
  • Matthias Gasnier, Australia
  • W. Christian 'Mental' Ward, Abu Dhabi
  • Mark Stevenson, Canada
  • Faisal Ali Khan, India