By on February 20, 2014

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The photo illustrating Zombie McQuestionbot’s query about what would it take to get you to buy a hybrid was of a Chevy Silverado hybrid pickup truck. I bet some of you seeing that picture didn’t know that Chevy even sold fullsize hybrid pickups and those of you who are familiar with them, may have dismissed the concept. It was called the 2-Mode hybrid system, introduced with great promise and fanfare but in the end it became the Rodney Dangerfield of hybrid drives. That’s too bad. Had the 2-Mode system been embraced by consumers on a wide scale, it might have saved more gasoline than all the Chevy Volts and Toyota Priuses put together.

Actually, the Dangerfield crack isn’t fair to Jacob Cohen, who in real life had a long and illustrious career, once he got his big break on the Ed Sullivan show. In contrast, the 2-Mode hybrid has come and pretty much gone in half a decade. Maybe part of the problem was that instead of first bringing it to the market on pickup trucks, GM introduced it as a package on it’s big body-on-frame SUVs. Perhaps the image of something that consumes combustibles as conspicuously as a Cadillac Escalade does, kitted up with four foot long “HYBRID” decals, evoked too much cognitive dissonance for critics and consumers to swallow but as contradictory as the idea sounds and looks, it made some sense.

There was a time when, unlike Mr. Cohen’s comedic persona, the 2-Mode system actually got some respect. Enough respect that in 2005 both Daimler-Chrysler and BMW joined General Motors in partnering to bring the system to production. There are vehicles from all four of those manufacturers using the 2-Mode system on the road today. Automobile magazine even named it the technology of the year in 2007.

2009-Escalade-Hybrid_r

The 2-Mode hybrid system is based around what is a sophisticated electromechanical automatic transmission. General Motors has long had a core competency in the development of automatic gearboxes. GM developed the first mass produced fully automatic transmission, Oldsmobile’s Hydramatic, and the corporation currently has two divisions devoted just to developing and building transmissions, Hydramatic, which produces gearboxes for cars and light trucks, and Allison, which makes transmissions for big commercial trucks. It was an Allison development for city buses that was the basis of the 2-Mode hybrid.

Two-Mode Full Hybrid GM-DCX Cooperation

GM 2ML70 hybrid transmission

A conventional single mode hybrid system, like Toyota and Ford developed independently, uses a planetary gear arrangement to connect both a combustion engine and one or more electric motors to a single driveshaft. Conventional hybrids can run on pure electric drive, combustion drive, or a combination of the two. That mode is known as “input split mode”. A second hybrid mode called “compound split mode” is more suitable for highway speeds, and always uses the combustion engine to drive the wheels, aided by the electric motors.

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Is “sophisticated” another word for “complicated”?

In the late 1990s, Allison developed a 2-mode hybrid transmission system for transit buses, now called the H 40/50 EP Series, that by now has been installed in over 5,000 buses around the world. Their latest hybrid transmission model is the H3000, for medium and heavy duty trucks.

2modeallison1

Allison H40 EP hybrid transmission. Note “Electric Drives” embossed on the case.

With Toyota’s Prius gaining traction in the market and giving that company some green cred, GM decided to implement a variation on the Allison design that would initially be used in fullsize rear wheel drive body on frame trucks and SUVs and later developed in FWD form suitable for passenger cars. What would become known as the GM 2ML70 transmission (in the BMW ActiveHybrid X6 and the Mercedes-Benz ML450 BlueHybrid it’s called the Allison AHS-2) added four fixed gear ratios to the mix. It has two 82 kW (110 hp peak) three phase permanent magnet AC motors, three planetary gear sets, and four selectively engaging friction clutches. A dampener replaces a conventional automatic’s torque converter.

Two-Mode Input and Compound Split Transmission

The transmission operates as two different continuously variable transmissions in one case. Electronic controls coordinate the electromechanical symphony, switching between the two modes to provide the ideal power, torque and fuel efficiency for the circumstances. One feature of the 2-Mode system making it particularly suitable for pickups and SUVs is that it allows moderate towing capabilities. Another advantage is that by locating the motor/generators where they are in the power chain, it amplifies their torque output the same way a conventional transmission amplifies the torque of an internal combustion engine, allowing the use of more compact motors, making it possible to fit it all inside the dimensions of a conventional automatic transmission. A more complete explanation, courtesy of About.com and Wikipedia is can be downloaded here (Word doc), and one suitable for transmission mechanics can be found here.

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GM and their partners were hoping for a 50% improvement in city gas mileage, with a lesser but significant increase in highway mileage. The system was introduced on 2008 Chevy Tahoes and Cadillac Escalades. Reviews from the time uniformly praise the system as working seamlessly and smoothly, yielding a real world improvement in fuel economy of about 25%.

2modecutaway

Despite the technical success of the system and the significant fuel savings, a lot of observers scratched their heads at GM’s strategy. What was getting headlines at the time were hybrids that were earning EPA ratings with big numbers, not SUVs that got 20 mpg. A hybrid SUV seemed like a rolling oxymoron. The thing, though, is that there was some reason to GM’s strategy if you look at the American fleet. The pickup trucks upon which those hybrid SUVs were based represent the largest segment of America’s fleet of cars and light trucks. Fullsize pickups are the best selling vehicles in America and have been for decades. They’re also the part of the fleet that gets the worst fuel economy. Improving the fuel economy of pickups from 15 mpg overall to 20 mpg saves a lot more fuel than improving the mileage of a compact car by a similar percentage. The small car is already getting better mileage so the same percentage increase is a smaller amount of saved fuel. Over 100 miles, going from 15 to 20 mpg saves 1.66 gallons of gasoline. Over the same distance, going from 30 mpg to 40 mpg saves half that amount, 0.83 gallons.

BMW's version. Note the AWD transfer case.

BMW’s version. Note the AWD transfer case.

Getting American pickups a 25% real world improvement in fuel economy would save huge amounts of fuel. Because it was pretty much a bolt in replacement for a conventional Hydramatic product (the 300 volt battery pack was mounted under the back seat), implementation was relatively simple, also allowing for the use of normal all wheel drive transfer cases.

However, when the latest generation of GM fullsize pickups were introduced in late 2013, they didn’t include a hybrid variant and none is planned. GM also stopped development on a front wheel drive version of the transmission. Chrysler discontinued the few models offering the 2-mode system and in mid 2009, Daimler and BMW  withdrew from the partnership. The 2-Mode today, if it’s known at all, is known as a bit of a technological dead end, not a tour de force. Considering that the thing worked and indeed saved significant amounts of fuel, what went wrong?

Two-Mode Hybrid Transmission Display

In a word, money. Well, mostly it was money, in a variety of ways, but there were other factors. To begin with, the 2ML70/AHS-2 is possibly the most sophisticated transmission ever made for a passenger vehicle. It was expensive to develop (the operational software to coordinate all that activity can’t be very simple) and expensive to build, which is why GM solicited partners in the project. I’ve seen the figure $10,000 cited as the manufacturer’s cost for a single transmission. A hybrid Silverado started at just under $40,000, a substantial increase over a similarly equipped four door Chevy pickup with a conventional drivetrain, just as the United States was about to enter one of the deepest and longest economic recessions in its history. Also, the first 2 Mode vehicles were introduced to the market in late 2007, for the 2008 model year, as General Motors was already on its inexorable path to bankruptcy. During 2008 and then going through the bankruptcy many programs’ development budgets were slashed or, like the Cadillac V8, were eliminated altogether.

Money wasn’t the only issue. The 2-Mode system went into production the same year that GM revealed that they were working on the Chevy Volt, an extended range electric car. A lot of the public and media’s attention that the 2-Mode hybrids could have gotten went instead to the higher profile Volt project. Inside GM, resources were being shifted. As a matter of fact, some of the same engineers who developed the 2-Mode system were granted patents that are at the heart of the Volt.

In addition to the paradox of trying to market a big SUV or pickup as an environmentally conscious consumer choice, GM’s marketers faced the fact that the 2-Mode system worked well at saving fuel in real life, but didn’t show outstanding results on the EPA test cycle. The 2013 Chevy Tahoe hybrid was rated by the EPA at 20 mpg in the city and 23 highway, which doesn’t sound very impressive compared to 16/23 for the conventional Tahoe. Apparently, advertising a 25% increase in real world gas mileage isn’t as appealing as touting big empeegees. New ICE technologies like direct injection and variable valve timing have come onstream, and with 6, 8, 9 and 10- speed transmissions coming on line, V6 and even V8 powered trucks can get very impressive government ratings, without the added cost and complexity of the 2-Mode system.

Since then, hybrids of all sorts, including million dollar supercars like the McLaren P1 and the Porsche 918, have proliferated. The idea of a $40,000+ luxury hybrid SUV doesn’t seem so outlandishly contradictory these days. I was at a Toyota media ride & drive for the new Highlander that Bark M reviewed here at TTAC recently and they told us that the hybrid Highlander starts at $47,900. The idea of an Escalade or Tahoe hybrid seemed to offend some folks just a few years ago, but Toyota only offers the hybrid drivetrain on the Highlander’s most expensive, Limited, trim level. The 2013 Tahoe hybrid, in a bigger, more expensive class of vehicles, started at $53,620, not that much of a stretch from what a Highlander Hybrid costs just a year later. From behind the wheel of a new Highlander hybrid, the big GM hybrids seem less silly than they did just a few years ago. Maybe they were just ahead of their time.

I wouldn’t write the 2-Mode off as some kind of technological dead end. One thing that’s true after over a century of people making cars and trucks is that what is old often becomes new again. Technologies and designs formerly rejected can be improved and implemented as materials science and control devices improve. I won’t be surprised if we see the 2-Mode hybrid or something similar appears at some time again in the future.

Ronnie Schreiber edits Cars In Depth, a realistic perspective on cars & car culture and the original 3D car site. If you found this post worthwhile, you can get a parallax view at Cars In Depth. If the 3D thing freaks you out, don’t worry, all the photo and video players in use at the site have mono options. Thanks for reading – RJS

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70 Comments on “A 2nd Look at the 2-Mode Hybrid – It Could Have Saved More Gas Than The Prius...”


  • avatar
    bumpy ii

    The 2-mode had some problems. It reduced the tow rating by some not-insignificant amount, and it was used in vehicles whose buyers are not focused primarily on fuel economy. Having said that, the biggest problem was marketing (cue Buickman). The 2-mode was an expensive standalone option that GM didn’t promote much at all, much like Quadrasteer before it. Making the 2-mode standard on the Escalades and the Denali would have done a lot to get the production volume up and build some brand awareness.

    IIRC Chrysler built a few hundred hybrid Aspens, then recalled and destroyed them a month later.

  • avatar
    doctor olds

    GM Powertrain chose the larger vehicles precisely because the fuel savings of a Tahoe Hybrid compared to its conventional counterpart are much greater than the similar comparison between a Prius and comparable small, efficient car. If the goal is reduction of domestic fleet fuel use which is, after all, the primary reason for CAFE, the 2-mode Hybrid provides more “benefit to society” than the max economy small hybrids.

    The estimated “internal subsidy” of the price amounted to about $15,000 per vehicle, iirc.

    The 2 modes seem to be a good deal on the used market, with prices comparable to the standard drivetrain trucks. I base this on only one or two data points. It may not be the general rule.

    • 0 avatar
      KixStart

      “If the goal is reduction of domestic fleet fuel use which is, after all, the primary reason for CAFE, the 2-mode Hybrid provides more “benefit to society” than the max economy small hybrids.”

      It provides no benefit at all if it doesn’t sell. And… it didn’t sell.

    • 0 avatar
      Dr. Kenneth Noisewater

      Good until you need a new transmission at any rate. Any indications as to the long-term reliability of these?

      • 0 avatar
        28-Cars-Later

        I thought the same thing. Since the transmission and battery pack were “drop ins” to a conventional model, perhaps you could also replace the transmission with a non-hybrid in the event its $10,000 factory cost transmission goes belly up.

      • 0 avatar
        doctor olds

        @Dr. Noisewater- No idea about long term dependability since I left in ’08. GM is certainly learning about them with the extended warranty, 8 years/80,000 for hybrid components and the standard 5/100 Powertrain warranty. One of the biggest drivers of the 5/100 PT warranty was to better understand long term dependability. GMPT viewed electric motor manufacturing including, this unit, as a core competency they wanted to develop in house along with engines and conventional transmissions. They are not going to abandon the technology, but continue to develop it.

        @kixstart- you can lead a horse to water, but you can’t make him drink. And you are right- no sales = no impact.

        GM was reluctant to pursue hybrid technology because it costs more than it pays. Even after eating $15,000 of the cost, the 2-Modes were still too expensive for consumers, in vehicles which are pretty expensive to start with.

        No doubt, Toyota has done a good job with Prius, but other hybrids don’t sell nearly as well. For the most part, better value can be obtained with lower cost economy alternatives. Hybrids are growing more for CAFE than consumer demand.

        • 0 avatar
          KixStart

          “GM was reluctant to pursue hybrid technology because it costs more than it pays.”

          Then it’s a real mystery why Toyota hasn’t gone under.

          You come at this sort of thing from with the perspective that GM knows what it’s doing. Nothing could be further from the truth.

          Hybrids can sell, they just must be a decent value proposition and have good utility. The Prius classic can be obtained for $22.5K or so (a modest discount from MSRP unless gas prices jump, then it’s a gold mine for Toyota). The Prius C is available for $19.something. They’re decent cars for those prices and they get phenomenal fuel economy and the market (people who want to save fuel) is programmed to look for smallish cars.

          I don’t know why GM chose to build the GMT900 HEVs. Even though we couldn’t know the manufacturing cost, it was obvious that they would not sell unless they were good value propoitions. The result was not even close. And that market is defined by people who don’t give a fig for fuel economy. If they did, they had far less expensive options for fuel savings (like Lambda). Who did GM think would buy these things?

          • 0 avatar
            doctor olds

            @Kixstart- GM knew they would be huge money losers, at least $15,000 per Tahoe/Yukon. Escalade was reportedly barely profitable on a unit basis.

            Neither this program nor the Volt were expected to be money makers. They were primarily technology development exercises.
            When the market collapsed, GM had bigger issues than promoting them.

            As far as Prius, it is certainly not a big contributor to Toyota profit. Its primary purpose is to sustain Toyota’s Green credentials. Nobody makes much on any small cars. They are a tiny slice of the market, and command low prices.

          • 0 avatar
            KixStart

            “Nobody makes much on any small cars. They are a tiny slice of the market, and command low prices.”

            Then it’s doubly mysterious that Toyota hasn’t gone under, as they make lots of small cars and not all that many high-profit trucks.

            In fact, not only have they not gone under (and they were financially challenged in 2008/9, same as anybody else), they didn’t a gift of $tens of billions to help them along and clean up their balance sheet and they’re still making far more money than New GM.

          • 0 avatar
            geeber

            Toyota sells plenty of trucks. Roughly 40-45 percent of Toyota Division sales come from light trucks, which includes crossovers, SUVs and minivans. Lexus sells more light trucks than passenger cars.

  • avatar
    carguy67

    re: “… GM introduced it as a package on it’s big body-on-frame SUVs …”

    It’s “its,” not “it’s.” Sorry–it’s a personal bugaboo.

  • avatar
    mfgreen40

    Ronnie—– another great in depth article, I was wondering what happened to that system. Does GM still own Allison? I was thinking someone like Penske bought them.

    • 0 avatar
      indi500fan

      Allison was sold to private equity (Carlyle Group and Onex Corp) in 2007 as GM was scrambling to find cash and stall off bankruptcy. It has subsequently gone public and is traded on the NYSE: ALSN

      • 0 avatar
        Conslaw

        The sale of Allison Transmission is as probably as big a reason as any technological or market issue for discontinuation of the 2-mode hybrid program in GM pickups. Why subsidize the development of the technology when another company will harvest the fruit?

        • 0 avatar
          doctor olds

          GM kept the Allison Transmission used in the HD Pickups as well as the 2 mode transmission, both of which are built at the Baltimore GM Powertrain Plant.

          https://media.gm.com/media/us/en/gm/company_info/facilities/powertrain/baltimore.html

          The plant’s website home page doesn’t show 2013 production but shows $23M in wages were paid in 2013.

  • avatar
    Dr. Kenneth Noisewater

    BTW, did the 2-mode vehicles have fully electrified accessories (such as AC compressor, electric steering and various pumps)? Seems stupid to me to have a hybrid that needs to run the engine to operate the AC.

    • 0 avatar
      doctor olds

      @Dr. Noisewater -“Seems stupid to me to have a hybrid that needs to run the engine to operate the AC.”

      It is not like you can snap your fingers and suddenly have all of that technology and be confident it will provide long term dependability.

      Electric accessories are among the major innovations of the Volt, and will surely be refined and developed for other applications.

      • 0 avatar
        KixStart

        “Electric accessories are among the major innovations of the Volt…”

        Another “innovation” that is really an attempt to catch up.

        • 0 avatar
          Carlson Fan

          Sorry but the Volt didn’t try to catch up to the Prius. It took a completely different road. If you don’t mind being tied to a gas pump or driving a penalty box, go for the ICE biased Prius. If you want a premium drving experience and the ability to run on electricity almost indefinitely, go for the EV biased Volt.

        • 0 avatar
          doctor olds

          wrt- electrical accessories, the VOLT leapfrogs the Prius. It is also a far nicer driving and performing car.

          Toyota is playing catch up with the Prius plug-in.

          • 0 avatar
            KixStart

            Exactly how, with respect to electrical accessories, does the Volt “leapfrog” the Prius?

            The Prius has had electric A/C, power steering and a water pump for a long time. It does not have an electric heat pump but then it doesn’t need one.

            If GM has all this great and wonderful tech, how is that they can’t match the Prius? Why can’t they make a true 50mpg hybrid that they can sell profitably at $24K MSRP?

            Toyota is not playing catch-up with the PHV. They are not trying to catch up. They are not interested in catching up. The Volt has established that a 38 mile EV range PHEV is a great way to lose money. Toyota is one to learn from other’s mistakes. They built the PHV because they *can*. It’s a Prius with extra batteries and a plug. It was an inevitable development and it probably has more to do with aftermarketers insisting on adding battery packs to stock Priuses (that’s how hard it is to do) than with concern for where the Volt is going. Never mind Toyota, Ford did the same thing, because it was trivial for them.

          • 0 avatar
            mkirk

            My 68 Cougar had an electric water pump as do many automobiles designed to travel 1/4 mile at a time. Nothing new here.

          • 0 avatar
            doctor olds

            @Kixstart Toyota does not have magically better technology than anyone.

            Your logic is circular.
            I explain the hybrid doesn’t make business sense, costing more than it pays, whether that cost is borne by the maker or added to the sale price. Then you ask why GM doesn’t make a knockoff of one.

            GM is along with every other manufacturer in that no one else has chosen to copy the Prius because it does not make business sense. GM is losing their money on Volt.

            Toyota’s growth in volume in NA is not in small cars. Prius is a small share of their sales. Their growth has been in larger and less fuel efficient offerings. Which actually make money.

          • 0 avatar
            KixStart

            Doctor Olds:

            “Toyota is playing catch-up with the Prius plug-in.”

            “I explain the hybrid doesn’t make business sense, costing more than it pays, whether that cost is borne by the maker or added to the sale price. Then you ask why GM doesn’t make a knockoff of one.”

            You make very little sense and you don’t realize it mostly because, as I said, you start from the presumption that GM knows what it’s doing. In fact, you seem to start from the presumption that GM is superior in every way and claim that Toyota is playing catch-up. But the Volt loses money. Why would Toyota play catch-up to a car that loses money when they have a car, the Prius, that makes money?

            And it’s extremely likely that the PHV sells for more than cost… it’s 95% bog-standard Prius with a plug and a different battery. This cost them little to develop and the NiMH battery delete allows more room on the BOM for a more expensive battery. GM alleged that the Volt 16KWH battery was $10K or so. Drawing a line through that, the Prius PHV 4.4KWH battery is perhaps $3K. Drop a $1K part, replace it with a $3K part and you’ve got $2K more in cost. The PHV is a Group 3, otherwise and is priced about $4K above the Group 3. They may be playing catch-up to GM in that they’ve found a way to lose money on the PHV but it’s not obvious how they’d manage it.

            You say hybrids are bad for business but Toyota’s product mix is about 10% hybrids, skews away from highly profitable trucks and towards small cars (they may be attempting to expand into more profitable larger vehicles – smart – but that’s not yet defining the mix) and yet Toyota is highly profitable. If hybrids are non-profitable and they’ve got fewer highly profitable lines to work with, how do they then end up spanking GM on profit with similar unit volumes?

            And you’ve been praising GM’s tech. If it’s so great, why can’t GM match Toyota? What’s the innovation in electric accessories when they’re commonplace elsewhere?

            You referred to the Volt as a technology exercise. That was 2007-2011, ten years after hybrids ceased to be a tehcnology exercise and became something that got sold in an attempt to make money. You say, “GM is along with every other manufacturer in that no one else has chosen to copy the Prius because it does not make business sense,” but that’s true and untrue. I didn’t say GM had to copy the Prius. It’s not necessary to “copy” the Prius to have a hybrid program. It’s true that Ford’s system is (or was until recently, I haven’t checked) very similar. Hyundai, VW and Honda are all doing hybrids without copying Toyota. If GM is a tech leader, why are they still doing technology exercises when they could be selling cars for money and making Toyota look bad?

            And you’ve said that electric accessories are one of the Volt’s innovations. The Prius has had various electric accessories for a decade (steering, A/C, water pump). What’s innovative about doing something that is commonplace?

            Carlson fan:

            If one wants to drive electrically, their Volt is closely tied to an outlet. If one leaves town, the Volt is then tied to a gas pump, but more often than a Prius because Volt’s CS mode fuel economy is poor.

          • 0 avatar
            doctor olds

            I don’t start with the presumption that GM is superior in ALL ways, but they assuredly are not the incompetents your tone and presumptions appear based on.

            You ability to understand what I wrote is due to your paradigms founded on fallacious understanding of the business and its dynamics. Businesses make choice as to technologies to develop and deploy.

            Sorry you can’t understand.

            GM has made the choice to pursue the light hybrid e-assist for mainstream use at this time. They are making a lot of money in NA with their current strategy.

          • 0 avatar
            KixStart

            Doctor Olds:

            “I don’t start with the presumption that GM is superior in ALL ways,…”

            Really? That’s not how you sound. The Prius playing “catch-up” to the Volt?

            “GM has made the choice to pursue the light hybrid e-assist for mainstream use at this time. They are making a lot of money in NA with their current strategy.”

            Are you referring to BAS-1/2 eAssist, as represented in the Malibu “Hybrid,” later in the Malibu “Eco” and the Lacrosse? Did it escape your notice that it was expensive, offered little useful improvement and they have mostly given it up?

            Or are you referring to the newly introduced “Idle Stop” systems (which I’m willing to call BAS-3), which haven’t been on the market long enough to prove out or even attract much notice?

            This is their third (or fourth, depending on how you look at it) “mild hybrid” system. They might be making lots of money on it but I haven’t seen any evidence of that yet. They certainly didn’t make any money on the previous versions. The one person I found with a Malibu mild hybrid who stood still long enough to ask a question said, “I wish I’d bought a Prius.”

            And why are you dodging my question about “electric accessories” and GM “innovation?”

          • 0 avatar
            doctor olds

            Volt is an electric car with all electric accessories. Its architecture enables fuel cell or any other source of electric energy storage. Prius can not operate without its ICE for any practical distance, even the Plug in.

            I may have exaggerated with the word “leapfrog” in connection with accessories.

            As I have said, hybridization doesn’t pay. Stop start is very much cheaper.

          • 0 avatar
            KixStart

            Doctor Olds: “As I have said, hybridization doesn’t pay. Stop start is very much cheaper.”

            Stop start might be cheaper but it’s not free and is it worthwhile? Does it make a difference at the pump?

            As for hybridization not paying, well, that’s GM’s perspective, other automakers may disagree.

            http://articles.latimes.com/2001/dec/19/autos/hy-prius19

          • 0 avatar
            doctor olds

            Based on the market share of hybrids, it appears car buyers don’t think a lot of them either.

            Stop start seems likely to be close to free, in that it simply requires a starter capable of more duty cycles in the vehicle’s life. I don’t know how much that cost is, and have read no technical articles on it. Feel free to provide data if I am off base.

  • avatar
    NN

    didn’t these things have massive reliability issues/CR black dots? I’d check one out 2nd hand if I weren’t scared of the questionable reliability and servicing on an abandoned technology.

    This was mostly a marketing failure, but the “20 mpg” number really just doesn’t impress people, either. The Highlander hybrid does carry more impressive MPG #’s, at a combined 28 mpg. Someone previously pointed out that if we used gallons per mile as an accepted measurement rather than miles per gallon, the benefits of driving one of these would be much more clear to a public that needs to understand the bottom line immediately to see any value in anything.

  • avatar
    Dirk Stigler

    The problem with all hybrids is that those extra ten or so MPGs are very expensive upfront, while being an almost-insignificant percentage of the vehicle’s TCO. That equation only changes at taxi/UPS truck annual mileage levels. That’s why the 2-mode system is successful in buses, but wasn’t in pickups and SUVs.

    Hybrids don’t make financial sense for any consumer. That’s why the Prius and the Toyota models over which it spreads its halo, and to a lesser-but-growing extent the Volt, are the big hybrid sellers. The appeal that actually gets people to buy is image, not savings at the pump. They may be very cool tech, and I’m glad to see bleeding-edge innovation in drivetrains for whatever reason, but it is basically the modern-day Volvo 240 wagon.

    • 0 avatar
      Conslaw

      The Prius does make financial sense. There are a variety of reasons. The first is that the entire car is optimized to make the fuel economy gain higher proportionally. Fifty MPG is readily achievable in a Prius when comparable midsized cars get 25. They kept the cost down, so the hybrid cost penalty is a lower percentage. The hybrid components keep down the wear on the gas engine, transmission and brakes, making the Prius exceptionally reliable. Finally, high resale value limits depreciation. Put all that together, and the Prius costs about $.47 per mile to drive, which is among the lowest of any car, and about 20% lower than the average sedan.

  • avatar
    Detroit-X

    Since GM struggles with getting conventional parts’ long-term reliability as good as Toyota, as evidenced for decades via Consumer Reports, why would anyone risk their money on such an expensive GM gimmick? I wouldn’t buy one even if it was cheaper than a conventional powertrain.

    • 0 avatar
      HerrKaLeun

      +10000
      plus the fact that I never heard of 25% real world mileage improvement. 2-mode also has the disadvantage to not allowing EV-mode or running AC/heating without the ICE on. All reasons why city mileage in real world is so great for Prius.

      How does GM 2-mode compare to Honda IMA (which got similar non-significant mileage improvements).

      in the end the costumer doesn’t care if the system is 2, 3 mode or whatever. Reliability, cost and real world mileage rule… and that is hwere GM sucks. the market decided less about 2-mode, it decided more about GM. A hybrid is a longer term investment, hardly something for sub-prime carmakers like GM.

  • avatar
    grzydj

    I think it was a pretty brilliant piece of engineering on the behalf of GM, but I think the headline is a bit misleading in that it implies that both vehicles are going to be used for the same task.

    Wait, most SUVs serve duty as hauling kids around, so maybe your anecdotal metrics are correct.

  • avatar
    CoreyDL

    Were the Escalades available without the big HYBRID wording? I know I’ve seen a couple, but I can’t recall if they all had the wording in addition to the HUGE hybrid badges or not.

    When these came out, I showed it to a few people, and got a unanimous “ridiculous” response.

  • avatar
    mcarr

    I think when people think of gas mileage they automatically think “highway” not “city”. These things gave 22 mpg highway at a time when you could get a non-hybrid version that got 20-21 mpg. Also, the fact that they used the 6.0 V8 (notoriously less efficient) rather than the 5.3L was a bit of a head scratcher. Shouldn’t the added power of the electric motors been able to handle the extra weight? The lowered tow rating was a nail in the coffin.

    Basically it was more expensive, towed less, and didn’t get “hybrid” mileage. The real question is, why did ANYONE bother with it?

    • 0 avatar
      Carlson Fan

      They used the 6.0 because it allowed the engine to run in 4 cylinder mode more often. So it was actually more efficient than the 5.3.

      • 0 avatar
        mcarr

        I didn’t realize the 6.0 in this instance had AFM. I don’t think any other installation of the 6.0 had AFM, did it?

        Still, the 5.3 is noticeably more efficient in the real world (having owned both). Had they designed it with the 5.3 and used more powerful electric motors, the engine could have engaged the AFM all the time on the highway. Imagine if it hit the market with a 20/25 mpg rating. That would’ve made people sit up and take notice.

  • avatar
    Vulpine

    Perception was a big part of the problem, along with complexity. Yet again engineers made a very simple concept overly complex and difficult; subsequently expensive.

    Please keep in mind that railroads have been using “hybrid drives” for over a century now and achieve huge economy ratings per ton-mile. Yes, they have become complicated too, but not to the extent that we see here. WHY do they have to make it so complex? Electric motors are known to offer their highest torque at their lowest speeds. At a speed of 0 (zero) rpm with full power applied it produces maximum torque, which then falls off as speed increases. Now, what we’re running into here is that most hybrids today are trying to put the un-sprung weight of the electric motors on the wheel hubs themselves. How about we look at this a different way–the way the GM design above attempts, but also fails.

    I fully agree that applying all that torque to a central drive shaft is the simplest and most economical method, even though we do fight the drag of numerous connections between the drive shaft itself and the wheels. What I don’t agree with is that we have to make it a truly “hybrid” system where engine output has to make even a rudimentary mechanical connection to the wheels; that’s just a waste of mechanical energy. You want big output horsepower and torque, just use either a bigger motor or daisy-chain several smaller motors onto the input of a transmission and have an engine strong enough to provide the generator enough power to drive them. The generator input still needs to have decent horsepower to drive it at maximum load but that’s where a battery pack would come in to add that boost when most needed. Four of those 110hp electric motors all chained together on the drive shaft would put 440 hp to the ground and still be smaller, lighter and less complex than this motor-boosted transmission.

    But lets carry this another step. As we can see here, the maximum power is most needed when starting a load moving and maybe when climbing a significant or long grade. Now, let’s put those four motors in place of a torque converter on a 2-, 3-, or even 4-speed transmission. Remember, as speed goes up, electric torque goes down. When taking on that grade, the vehicle will slow down to the point where torque matches load, which without a transmission is now limited by the available battery/engine combined output. On a steep but short grade the drop in speed might be relatively insignificant, but on a longer grade you would experience a second drop when battery power ran out. On the other hand, by using a transmission those motors would apply torque sooner and potentially keep the vehicle at road speed or hold a higher speed longer than running on those motors alone. Interestingly, this basic concept has been demonstrated by a converted Land Rover some years ago capable of raw rock-crawling side by side with diesel-powered models–though it’s battery only gave it a 1- to 2-hour range.

    Ultimately what this means is that a modest engine–let’s say a typical V6 (does not need turbocharging)–could run on three cylinders when at cruise at 100hp or less and still offer over 400hp to start the load and over 300 hp to keep that load moving even on a grade AFTER the battery charge is depleted. Turbocharging could up that hill-climb ability to full output but still manage to stay out of that turbocharger for maintaining steady speed on the flat (unless you’re a lead-foot).

    • 0 avatar
      DC Bruce

      What you describe sounds very similar to the hybrid system implemented in the new Honda Accord. There’s no clutch/transmission per se, just electric motors driven off a battery charged by the engine. At roadway speeds, the engine does directly engage the roadwheels. It’s also worth mention that the Honda system generates some pretty amazing numbers, considering that its less of a “penalty box” vehicle than, say, a Prius.

  • avatar
    Vulpine

    I wrote the above comment before reading any of the prior commentary. Most of those earlier comments proved my very first statement: “Perception was a big part of the problem, along with complexity.”

    Now, I’ll admit I don’t live in Texas, but I have lived in nearly every region of the country except the far northern tier and… Texas. I understand the far-away aspects of living in the plains. I understand the remoteness of living in the desert. And I certainly understand living in the crowded confines of living in cities and relatively densely-populated rural settings that exemplify Pennsylvania and the north-east corridor. The MPG perception is a killer when ALL you look at is the highway mileage. Quite honestly, one of the biggest causes of poor highway mileage of these big trucks and SUVs isn’t their size and weight, but rather their aerodynamics. But that’s a different argument. What these people should have been looking at is their City/Combined mileage which is where the electric boost properly shines. A 30%-50% mileage boost here means going from 10 or 12mpg to 14 or even 18 mpg where EVERY vehicle’s gas mileage is at its worst. Most of these trucks spend 80% of their lives at 50mph or less, not at 65 and higher.

    The mistake made by GM and the others is that they didn’t emphasize this point–the real strength of the system. Because it wasn’t marketed properly, the system itself failed to sell because nobody understood it and they were blinded by its weakest aspect.

    • 0 avatar
      KixStart

      Ironically enough, GM also changed other aspects of the hybrids, which probably did far more to improve their highway fuel economy, at a fraction of the cost, than the hybrid system itself.

      The V8 was a variable cylinder V8. Cruising down the highway under light load, it could shut down half the engine. Their aerodynamics were also improved.

      I have always wondered why they didn’t apply these changes to the rest of the lineup and go for noticeably better fuel economy across the board.

      • 0 avatar
        doctor olds

        My ’08 GMC Sierra has AFM. Has it not been a standard feature of GM Pickups and Big SUVs for the last 6 years?

        The challenge with AFM is to maintain pleasability.

        Pleasability was the biggest issue with the Cadillac V8-6-4 as I recall from the Olds-Cadillac Dealers in my District. It was easily defeated as well, iirc.

        • 0 avatar
          KixStart

          “My ’08 GMC Sierra has AFM”

          Then I was mistaken but I looked it up at the time on Edmunds and perhaps some other sources and there was no mention of AFM or VCM in any engine other than the hybrid.

          • 0 avatar
            KixStart

            In fact, the Wiki article today makes no mention of it in a pickup:

            http://en.wikipedia.org/wiki/Active_Fuel_Management

          • 0 avatar
            doctor olds

            Well, that shows you may want to consider how much of what you read about this stuff is really true!

            I assure you the Pickups from at least ’08 on, have AFM.

            One of my observations from 40+ years with an automaker is that if a journalist gets the story right, it is purely coincidental. The disinformation is amazing, and a big reason I comment here.

            I get a kick out of the guys who tell me not to believe my lying eyes in favor of what they read on their favorite blog.

          • 0 avatar
            KixStart

            We can fault GM for not getting the word out. Current advertising also implies that this is new (it’s now being used to counte EcoBoost’s mindshare).

      • 0 avatar
        indi500fan

        Cylinder deactivation (“displacement on demand”) has been a feature of GM engines at least since 2004.
        Of course this doesn’t include the Caddy V8-6-4 of the early 80s.

        • 0 avatar
          Carlson Fan

          Prettty sure your wrong about that. AFM, Active Fuel Management, was introduced in 2007 when the GMT-900 models were released.

          I own an ’07 Tahoe with AFM. The transition between 4 and 8 cylinders is absolutely seemless. You cannot tell or feel when the motor is switching between 4 & 8 cylinders.

          The problem with AFM is that it just doesn’t run in 4 cylinder mode long enough to make much of a difference. Even at 55 MPH on a level two lane road with the CC set it is constantly switching back to V8 mode. That little 5.3 just doesn’t have the torque to keep it in 4 cylinder mode. That is exactly why they used the 6.0 in the hybrid models.

          • 0 avatar
            Brian P

            I believe one of the things changed with the new (K2XX) direct-injection 5.3 is that it is now capable of running in 4-cylinder mode up to higher speeds and loads. At 55 mph, the power demand to push the truck down the road ought to be well within the capability of a 2.7 litre 4 cylinder.

  • avatar
    RS

    Along with the issues mentioned above, the Big ‘H Y B R I D’ decal on most wasn’t a good move by GM design.

  • avatar
    JimC2

    GM doesn’t get much love when they try to get good bang-for-buck with new technology by trying to do something sensible- and incremental improvements to full size pickup truck and SUV fuel economy is a sensible thing.

    @28Cars- my math off the top of my head figured about $5,000 over 100,000 miles (15mpg vs 20mpg, $3/gal), which is essentially similar to your estimate. (Anybody can stretch the numbers in either direction, but…)

    Anyone remember when GM developed ABS VI about 25 years ago? GM figured it would be a good safety investment to bring affordable antilock brakes across its product lines (back when ABS was still relatively special). Instead, the market seemed to prefer airbags, airbags, and more airbags- probably because airbags are tangible to a car shopper who is shopping for “appliance transportation” and not interested in reading a brochure about how ABS actually works. (Of course, ~15 years later, ABS had become practically universal in the U.S. market.) Not exactly a good parallel example, but there are similarities there in that they tried to do a good, sensible thing but the market went a different direction.

  • avatar
    schmitt trigger

    I’m an engineer, and consider myself fairly technical savvy, and still have a hard time understanding its operation.

    I suspect that when one of this requires repair, I suspect it would have to be shipped to a GM servicing facility. Can’t see nobody else capable of repairing it. Lots of time and plenty of $$$

  • avatar
    doctor olds

    @Schmitt trigger- Just out of curiosity, would you tackle the overhaul of a 6, 8, or 9 speed automatic? This is not all that much different to repair. It just incorporates a couple of 80HP electric motors. Like those other transmissions, the process for the this trans will likely include remanufactured units for service. The control is sophisticated, the parts are just electro mechanical. The cost will depend on what the long term failure modes and wear out parts cost to service. It is fair to expect little aftermarket interest with the small volume sold.

  • avatar
    allenped

    there was to be a Saturn Vue 2 mode but was never created. it would have been the first car to offer two different hybrid drivetrains (2 mode and mild). shame it did not work out. or was used onto the equinox. it was a good idea but too expensive and offered as a premium option. shame the technology is just going to disappear


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