By on April 7, 2014

2014-GM-Eight-Speed-Automatic-Transmission

GM’s upcoming 8-speed automatic, dubbed the 8L90, will be a cornerstone of their new rear-wheel drive cars – and the 2015 Corvette lineup will be among the first to get it.

Back in December, our own Ronnie Schreiber gave us a preview of the new 8-speed gearbox via a leaked SAE paper. Although it carries the same footprint as the outgoing 6L80, the 8L90 is full of improvements. First gear is shorter, for better acceleration, while fuel economy is said to be improved by 5 percent across the board. With 6-speed automatic C7 able to hit 28 mpg on the highway, a 5 percent gain translates to 29.4 mpg – but it wouldn’t be shocking if Chevy pulled out all the stops to hit the magical thirty em pee gee number, if only for marketing bragging rights.

Along with the Corvette, the 8L90 is expected to appear on other rear-drive cars, as well as trucks. The addition of the 8-speed auto will certainly be a nice boost for GM’s full-size SUVs and pickup trucks, not to mention rear-drive Cadillacs and the upcoming Camaro.

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92 Comments on “Could The 2015 Corvette Stingray Crack 30 MPG With New 8-Speed Automatic?...”


  • avatar

    Take a look at the “TUNE TIME” Stingray I posted and the C7 on dyno.

    I didn’t like the C7 till this weekend.

  • avatar
    PrincipalDan

    Hmmmmmmm this could make the Camro/Mustang rivalry a little more interesting. The data I’m seeing is still saying 6 speed auto/6 speed stick for the ‘Stang. Will a 8 speed auto V6 Camaro beat the fuel economy of an eco bost 4cyl Mustang with 6 speed auto? How will Ford respond?

    • 0 avatar
      bball40dtw

      Ford will have another transmission, eventually. Per Ford’s product launches of past, including the last Mustang, new engines or transmissions will arrive after the first model year or so. Ford has a 10-speed coming out in 2015-16, but it may only be for trucks.

      • 0 avatar
        PrincipalDan

        On a slightly odd note, we are now entering a time period when the average new car automatic will have MORE gears than the available manual transmission (if one is available). That will be a little strange to me in and of itself. Ex: Current Covette will have a 7-speed manual and an 8 speed automatic. Fiat/Chrysler is adopting a 9-speed auto while their manuals stay 6-speed.

        • 0 avatar
          TR4

          History repeating itself. GM’s Hydramatic of the ’50s had four speeds at a time when most American manuals had only three.

        • 0 avatar
          pragmatist

          Basically it gets to the point where too many manual gears becomes downright inefficient (as well as tiring and potentially confusing).

          With some of these cars, the auto would be out of (very short ratio) first before the driver would even have time to work the clutch.

    • 0 avatar
      redav

      I was wondering the same thing. Will Ford go the DCT route? (Does it already have a DCT?)

      • 0 avatar
        bball40dtw

        They don’t have a DCT that can handle the power loads of the Mustang. Right now they only have a dry clutch for FWD applications. In the US, its only in the Fiesta and Focus.

        • 0 avatar
          pragmatist

          Ford doesn’t need to have one. Transmissions are rapidly becoming cross-brand systems produced by specialist companies. Not a bad thing, really.

          • 0 avatar
            bball40dtw

            Ford is going in jointly developing transmissions with GM. Although they seem to be licensing wet DCT units from Getrag in the future, the bulk of their US product will continue to feature Gm/Ford developed boxes. Manual transmissions are another story. The current Focus dry DCT will probably be around into the next generation Focus.

    • 0 avatar
      That guy

      GM has a much larger RWD car portfolio than Ford does, they’ll always be able to better amortize parts due to this fact. Ford probably won’t have an answer until the joint 10spd is out.

  • avatar
    That guy

    My next vehicle purchase will likely be in the summer of ’16, hopefully this is in the ATS 3.6L and SS by then. It would fix the biggest flaws with both those cars.

    • 0 avatar
      redav

      Just curious, what’s wrong with the current transmission?

    • 0 avatar
      bball40dtw

      I’ve only driven the 2.0T ATS with the manual. Is the automatic in the ATS really that bad?

    • 0 avatar
      That guy

      The transmission itself isn’t bad, but the ATS doesn’t get off the line like some of its competitors do and the SS gets pretty lousy highway FE. With a lower first gear and a higher top gear, this would help with both issues.

      • 0 avatar
        APaGttH

        The SS issue is the 6.2L LS3 under the hood when it comes to FE.

        More gears will only help incrementally.

        • 0 avatar
          That guy

          If GM could bump it up to 23 or 24mpg, it would be a worthwhile improvement. As it sits right now, a 6.2L Sierra has better EPA ratings than the SS sedan.

          • 0 avatar
            Hummer

            The SS uses an LS style vs the trucks LT.
            While the SS would see a massive fuel improvement from the LT, it wouldn’t be quite as reliable (IMO).
            I prefer the LS, but there’s nothing wrong with the LT.

        • 0 avatar
          3Deuce27

          The ‘SS’ uses the ‘L99′ engine to elevate fuel mileage efficiency with the automatic.

          The L99 is derived from the LS3 with reduced output but adds Active Fuel Management (formerly called Displacement on Demand) and variable valve timing, which allows it to run on only four cylinders during light load conditions.. wiki

          Applications: 2010–present Chevrolet Camaro SS (Automatic Transmission)

  • avatar
    fredtal

    Yes it could hit 30mpg at 60mph in 8th gear which I’m sure is great for cafe standards? The reality is no one in their right mind buys a Vette because it gets great gas mileage.

    • 0 avatar
      redav

      Current Vettes already can do that, but that’s not the same thing as EPA numbers. Just because the car is built for performance doesn’t mean owners like wasting money. A 30 mph label would be a huge selling point.

      • 0 avatar
        stuki

        Gearing strategy for headline grabbing mpg, tend to be very much at odds with gearing for “performance.” So much at odds, that driving the mpg geared cars for performance, end up yielding not only worse performance, but worse economy as well. All from ending up with the silliest shift points and shifting strategies, in order to drive around the limitations of the tranny. Probably less of an issue with 8 speeds and small block powerbands, but still a nuisance. Resulting almost exclusively from idiotic methods for measuring fuel economy; forced into existence by the usual culprits; Massa Gommiment and her army of at best half litterate sycophants.

    • 0 avatar
      That guy

      I think a lot of the Corvette’s popularity comes from the fact that a relatively normal person can afford to buy one and keep it running. Fuel economy is part of that equation.

      • 0 avatar
        NormSV650

        My 2000 C5 with manual trans could see 34-36 mpg at 60 mph highway cruise. I srove 450+ miles and plenty left in the tank. Sixty miles per hour is like 1,250 rpms. The C5 had msaller 17/18″ wheel and rubber setup.

        • 0 avatar
          golden2husky

          When my C7 is delivered and broken it, I’ll post the cruising mileage. Manual trans, of course. Mileage was not a factor in the purchase, as my commuter is a hybrid. But if I can save a few bucks on a road trip that is some nice icing on the cake.

        • 0 avatar
          Hoosier Red

          That might be a little high. My 2003 C5 M6 will certainly break 30 mpg at 60 mph and I agree with the rpms, but I’ve never seen 36 mpg unless I was going downhill.

          • 0 avatar
            NormSV650

            My C5 was purchasd at 9,500 miles, sold at 90K miles. Including allot of track miles, intake/exhaust restrictions reduced, ecu tune that worked over fuel enrichment and some weight reduction with 18 lbs Sparco seats/non-runflat tires. A good alignment always helps along Royal Purple fluids.

          • 0 avatar
            Hoosier Red

            Interesting……

      • 0 avatar
        pragmatist

        Compared to payments, insurance etc, the difference in fuel cost between 25 and 30mpg is not all that much. If you want a Corvette, and are already willing to pay for it, $25 a month will not change things.

    • 0 avatar
      danio3834

      Considering the low volume of Corvettes sold to the rest of the GM fleet, the increase in fuel economy wouldn’t impact CAFE averages much. This is being done to market extra feautres and competitiveness. Because 30>26 and 8>6.

      • 0 avatar
        JimC2

        Welllllll, yes and no. Anybody remember when they introduced the 1-4 shift gate on the manual transmission Corvettes? Under light acceleration (as in during the EPA test) a little thingie would deflect the 1-2 shift and make you shift into 4th… and this improved the test results. Under moderate and/or heavy acceleration, the thingie would be disabled and the car would have a normal shift pattern. I think this was in the early 1990s. The EPA test results are always important- at least a little important.

        • 0 avatar
          CJinSD

          The new Corvette and the Viper still have it.

        • 0 avatar
          raph

          Current Mustang with the MT82 has skip shift as well.

        • 0 avatar
          danio3834

          Yes, fuel economy numbers matter to some degree. On a low volume, purpose built sports car, they matter less than with other vehicles. In this case, it’s basically a bonus.

          The cost of the addition of the skip shift feature on the T56 is insignificant compared to the development of a new transmission.

          Like the 8L90 to the 2010s and 8+ ratio transmissions, the T56 was added to the F-bodies and Corvettes of the 90′s because sports cars of the 90′s had 6 speeds. Not 4 or 5 speeds, or 4 speeds with an overdrive unit tacked on that could come on in the 3 latter gears. The 4L60E equipped cars could acheive about the same fuel economy as the T56 cars when they were introduced, but at a time of relative cheap fuel, few manufacturers were really pushing development of automatics with more than 4 forward ratios, so they were stuck with that.

          • 0 avatar
            PonchoIndian

            ” The 4L60E equipped cars could achieve about the same fuel economy ”

            Have to disagree slightly with this. First hand knowledge, the and F-body with a manual will easily pull down 29-31mpg on the highway, the 4l60 with 2.73′s will do 26-27 and 4l60 with 3.23′s will do 23 to 24.

            I do agree that fuel was cheap and with these engines, other than for fuel economy more than 4 speeds really isn’t needed.

    • 0 avatar
      Slare

      You’re right, but it’s awfully nice to mushroom slap someone in the face with the 30mpg figure when they criticize you for driving such a “wasteful” vehicle. It makes them so mad, like some sort of beautiful reverse Prius smugness.

  • avatar
    DenverMike

    No surprise. It’s relatively small and lightweight, so when combined with ground hugging aerodynamics and double overdrive, Corolla mpg is a given. If driven conservatively. Not what it was designed for, or its target demo, but a result or byproduct of all said things.

  • avatar
    dal20402

    The fixation on the highway mpg number by itself just plays into the hands of marketers. Who drives their Vette nowhere but on the highway? Who buys a Vette to drive along at a steady 60 mph? If you want to do that, you’d buy a LaCrosse.

    The real-world city number will still be the same 16 mpg as always.

    • 0 avatar

      People cruise in their ‘Vettes on open road all the time…so…yeah.

    • 0 avatar
      stuki

      If anyone cared about obtaining realistic, real world, mpgs; the test wold include a weighted measure of at least the following:

      1)sitting gridlocked in stoplight to stoplight in rush hour, 1 car per green.
      2)highway driving @75 cruise control
      3)suburban stoplight to stoplight, with open roads @ 1/2 the car’s max acceleration and braking
      4)All out attack on some reasonably varied track.
      5)drag racing
      6)an autocross.

      For any vehicle rated to tow more than it’s own weight, repeat tests both empty and at 2/3ds max tow load.

      Noone buys a ‘vette to drive it like a Prius. And even Prius drivers don’t drive their cars the way the EPA does.

      My algorithm is probably off by a bit, but infinitely more realistic than what the EPA uses, which is just plain silly.

      • 0 avatar
        golden2husky

        Which is why in the early days of EPA mileage estimates, the ads were required by law to emphasize the city number. That rule went out the window when Reagan went on a mission to reduce silly regulations, IIRC.

      • 0 avatar
        danio3834

        And after they implement these ridiculous test methods, there will still be people complaining they don’t get the advertised mileage. *your mileage will vary*

        The best thing to do is test the vehicle yourself to see what kind of economy to expect under your conditions, or consult a reliable rag and see how they tested it and verify the mileage they got.

        The EPA numbers are only necessarily good for comparing two vehicles directly to one another, they aren’t reliable to determine what you will see if you drive it. They’ve made efforts to update the testing to try and make it more representative of the real world, but the the real world can mean different things to millions of people.

    • 0 avatar
      Slare

      16mpg? Maybe in New York or LA. I drive with a very heavy foot and my C6 gets ~23 combined. 16mpg would be ridiculous traffic jam driving or quickly arrest me driving.

      • 0 avatar
        dal20402

        I have a G8 GXP — same engine and transmission as the C6, but with a good deal more weight.

        16-17 mpg is my regular average in mixed driving.

        With an entire tank in block-by-block city driving (Seattle) my mileage will be 13 mpg if I drive very gently or 10 mpg if I drive it like I stole it.

        Highway cruising at a constant 60 mph will get me 25 mpg.

        I’ve never had a car with such a wide range or such sensitivity to driving style before this one.

        • 0 avatar
          PonchoIndian

          I’ve often wondered how much mpg would improve if Pontiac put lower gears in the rear. When the GTO came out they put 3.42′s in both the 6 speed and the auto. The auto got something like 21mpg and the 6 speed got 25 I think. I bet though could have made 2:73′s standard in the auto and got a lot of that mpg back.

          Love your G8 GXP.

          • 0 avatar
            danio3834

            They probably could have, but the market for the GTO was so focused on performance buyer, and the overall amount sold so small that they didn’t bother to make a fuel economy package an option.

          • 0 avatar
            dal20402

            Lower gears would help with the highway MPG, but they wouldn’t have much effect in the city since I’d just wait longer to shift.

            The 3.45s in the GXP already give me fairly low RPM in sixth at cruise speeds.

        • 0 avatar
          Slare

          Your G8 GXP is ~800lbs heavier with much higher drag. Thus your 16-17 mixed to low 20′s in a vette, and 25mpg highway to ~30mpg in a vette. Not a stretch or fiction at all.

    • 0 avatar
      3Deuce27

      ” Who buys a Vette to drive along at a steady 60 mph? ” Obviously, no one, but no matter what I’m driving, on a trip, I’m going for the best MPG I can get, not the fastest trip. Its a game with several positive results… MPG, pollution reduction, longer drive component life, and lowered stress levels, too name just a few.

  • avatar
    87 Morgan

    I know a couple of guys with vettes, typical target market. Middle aged, kids in or close to college etc. These guys drive their vette regularly to work and that involves the typical mundane commute where using the car as a performance machine is not an option. So mpg is an issue, or rather a nice to have.

  • avatar
    Lorenzo

    Last April, it was announced that Ford and GM were jointly developing 9- and 10-speed automatics for both FWD and RWD applications, including SUVs and trucks (Autoweek, 4-15-2013). I believe Ford builds a version of the ZF 8-speed automatic under license. Does that make this GM 8-speed a stopgap rather than a major step forward?

    • 0 avatar
      bball40dtw

      Originally it looked like they were going to use a ZF 8 speed and then jointly develop a 9 speed FWD transmission with GM. I don’t know if they are using that 8 speed anymore since they annouced that the 10 speed is in development. I haven’t heard anything about the ZF 8-speed and Ford since that annoucment.

    • 0 avatar
      LeadHead

      Ford builds a licensed ZF6 6-speed for the truck sand SUVs. Chrysler builds a licensed ZF8 speed. However, this GM 8L90′s specifications match up perfectly with the ZF8 speed, so I’m almost positive it’s also a licensed ZF8.

      • 0 avatar
        danio3834

        “It’s engineered by GM, internally, and many of the parameters were focused on this car,” said Corvette chief engineer Tadge Juechter, at a pre-show event. “So it’s almost a custom transmission.”

        http://www.motorauthority.com/news/1089778_gm-8-speed-in-corvette-z06-shifts-faster-than-porsche-pdk-heres-how

        Whether they licensed any specific features from ZF prior to engineering it specifically for the Corvette remains to be seen. But the guy responsible seems to indicate it’s one of theirs as it’s mentioned later in the article that it was designed by GM “from scratch”.

  • avatar
    NMGOM

    Who cares?

    Maybe I’m one of those rare post middle-aged guys who burns rubber and pulls 1 g’s around corners.
    See avatar above.
    I don’t give a good rat’s posterior about em pee gee’s.
    I give an elephant’s balls about em pee owwwwers.

    The manual is just fine, thank you.

    ——————-

    • 0 avatar
      redav

      That’s nice.

      But if you had the same performance but with a choice between the better “em pee gee’s” or worse, which would you rather have?

      • 0 avatar
        NMGOM

        redav – - –

        Times, they are a changing.
        There used to be 4 major advantages to having a Manual Transmission (MT):
        1) Acceleration;
        2) Fuel Mileage;
        3) Car control:
        4) Driving involvement.

        Nowadays, a good 7-9 -speed AT can match or surpass #1 and #2.
        But #3 is still an issue with torque-converter systems.
        And #4 can be only slightly approached with manumatic PDK-type systems at much higher cost, higher maIntenance, and lower reliability.

        Manual Transmissions are NOT about performance or fuel mileage.
        They continue to be about simplicity, vehicle control, and driving involvement.

        So, which would I rather have?
        Well, let’s put it this way: I have 5 vehicles, – - – two pickup’s; a Jeep; a BMW sedan; and a BMW Z4.
        All have RWD and MT’s. Get the picture?

        ————————

  • avatar
    Master Baiter

    If you can afford a Corvette, you can afford gas. The car’s hood sits a foot and a half off the ground (thanks to its 1950s OHV engine technology) and it has the frontal area of a nat. So it can lumber along on four cylinders at 1200 RPMs on the highway. Who cares?

    • 0 avatar
      redav

      The whole “if you can afford a Corvette, you can afford gas” argument is lame & pointless. Do you really think Warren Buffet doesn’t negotiate prices just because he’s rich enough that he doesn’t have to? Do you really think that people who are wealthy don’t like saving money?

      It’s not like they’re neutering the car to make it cheaper to own.

      • 0 avatar
        golden2husky

        …..thanks to its 1950s OHV engine technology…..

        We have a winner in the ignorant comment of the day contest. Considering the similarity to a 1950′s engine, heck you might as well say that “all those cars with the 1800′s piston technology”….

        • 0 avatar
          raph

          Well his handle is “Master Baiter”…

          Anyways you bring up a good point. Todays OHV engines while comparatively simple to a multi-cam and multi-valve engine is still packed with some impressive technology when it comes to the air flow department.

          By way of example GM’s LS7 cylinder head outflows Ford’s coyote 4 valve at every lift point on their respective engines although the comparison comes with some caveats as the coyote motor has a 3.629″ bore and the LS7 has a 4.125″ bore and one is as cast and the other CNC’d

          • 0 avatar
            3Deuce27

            Req; “example GM’s LS7 cylinder head outflows Ford’s Coyote 4 valve at every lift point_ though, The Coyote has a 3.629″ bore and the LS7 has a 4.125″

            This only applies in a particular dynamic environment, not a static head flow measurement and involves a lot more elements then the static flow at measured lift not involving a cams design profile. Involving swept area, cam design and upstream and down stream factors, effect actual net/realized flow.

            Actual power produced, involves even more design elements.

            I would curious as to the source of that info, Raph, that gives dynamic flow numbers.

        • 0 avatar
          PonchoIndian

          Nothing like those early 1900′s cars with OHC technology too.

          Makes me laugh when people say that OHC’s are more modern than OHV engines…

          • 0 avatar
            danio3834

            Many flatheads were developped well after the advent of OHC and OHV engines. Perhaps because they are of a newer design, we should go back to that…or not.

          • 0 avatar
            PonchoIndian

            Danio
            Your point?

          • 0 avatar
            danio3834

            …that just because a particular design characteristic post dates another, doesn’t mean by definition it is better.

  • avatar
    johnny ringo

    Eight speed, nine speed–ten speed automatic transmissions? This is starting to get weird–seriously why not simply go to a CVT and be done with it. At least to my way of thinking that would be a superior solution.

  • avatar
    3Deuce27

    In the real world, carefully driven Corvettes have been getting 30+ mpg since the introduction of the LS series engine. This is just a possible EPA rating.

  • avatar
    Jellodyne

    Even if some of you don’t care about the actual MPGs, it actually affects GM’s ability to actually sell these things without selling 10 1.0L econoboxes to greenwash their CAFE balance. Which is to say the less a burden it is on their corporate fuel economy numbers, the less it ‘costs’ them to sell it.

    Plus did you ‘who cares’ guys see that it also gets off the line quicker?

  • avatar
    DC Bruce

    A bit of perspective. This would be better fuel economy than achieved by a classic air-cooled VW Beetle.

    I managed to get 30 mpg on the highway out of a Karmann Ghia, a more aerodynamic VW with less frontal area. But this required jetting the carburetor really lean, so lean that the engine ran hot and “driveability” was not too good.

    People bought these cars in the day because they “didn’t use much gas.”

    Admittedly, the ‘vette will have to be driven gingerly to beat the VW in town, but still — when you think about it — this is a huge accomplishment.

    And the Beetle’s observed top speed was between 65 and 70 mph.

    • 0 avatar
      Maymar

      Peter Egan even wrote an editorial to that effect about ten years back. He was marvelling that the beater Park Avenue with its 3800 would easily see 30 mpg highway, just like his old Beetles.

      Of course, as mentioned, the Corvette has been cracking the 30mpg without effort since ’97, but it’s still impressive given the level of performance they continue to wring out of it.

  • avatar
    sportyaccordy

    Man people sure love to posture over the internet. Newsflash, nobody is impressed by dismissals of fuel economy. If GM can get the C7 to deliver the performance required while using as little fuel as possible, how is this a bad thing?

    Not to mention, the 8AT can broaden the car’s usage… if it’s programmed right, which I am almost certain it will be, it will be a track monster when you want it and a torquey fuel sipper when you need it.

    If I break 25 MPG on the highway in my Z with nearly 200 less HP it’s a miracle. There is literally no upside to crappy fuel economy… aside from, I guess, bragging about how much you spend on gas, or posturing to show how little gas costs affect you.

    • 0 avatar
      stuki

      What concerns many “performance oriented” drivers, is that more and more “performance” cars, are being designed to meat a very limited number of headline specs; 0-60 and EPA mpg being the two biggest of them. And everything is being oriented towards those goals only.

      Which can often come at the expense of both driveability, real world performance, and even actual observed mpg. 2nd gear gear reaching exactly 60.1 mph, and 6th giving 1100rpm @60 or whatever, may not be the ideal gearing for a given powertrain if the goal was all around performance. Neither may maximum slipperiness at the expense of downforce. Nor molasses grade throttle response. for the first 90% of gas pedal travel, to be followed by an on off switch as you floor it.

      Cars should be designed with input from their makers and their drivers. Not a bunch of busybodies who cannot stay out of the lives of others.

      • 0 avatar
        golden2husky

        Sometimes designing for economy means the trans is always jumping to the highest gear as fast as possible which can be annoying to say the least.

        ….Cars should be designed with input from their makers and their drivers. Not a bunch of busybodies who cannot stay out of the lives of others….

        Which will result in cars that swill fuel and leave our country vulnerable, just like in the past. Then the “busybodies who cannot stay out of peoples lives” instead will send young lives to their deaths fighting people that hate us so we can keep the supplies of crude moving. There is no free lunch.

        • 0 avatar
          stuki

          Yes there is free lunch. Starve the busybodies by preventing them from taking other people’s money for food (or anything else). To the point where they have no choice but to either do something productive with their pathetic little lives, or just starve. Either way works fine.

          So, in your warped world, the only thing standing between everyone driving around in cars that swill fuel, is a bunch of nonproductive busybodies?

          If it was not for some apparatchik messing up your transmission, you’d just wantonly sit there and burn fuel by the thousands of gallons. Just because …. because of what exactly?

          And, in a world without busybodies being in a position to meddle in the lives of others, exactly how are they going to “send” anyone anywhere?

          I know you’ve probably suffered through the same publicly funded indoctrination machinery as the rest of dronedom, but please, please; at least try..

          • 0 avatar
            golden2husky

            There once was a time where things worked the way you would like. The industrial revolution period, the Gilded age. That’s when there’d were no “busybodies” at all. You really want to go back to that world? No thanks. Life sucked for all but the very top.

          • 0 avatar
            rpn453

            “Life sucked for all but the very top.”

            Obviously not, as those people did plenty of reproducing. Surely people who are unhappy wouldn’t reproduce and burden their children with such misery. Humans are far too intelligent for that, so they must have enjoyed life; at least enough to be optimistic about the future.

      • 0 avatar
        sportyaccordy

        You think the Corvette isn’t designed with input from owners?

        Corvette’s 7 speed tops out at 50 and 71 in 1st and 2nd respectively. Other cars like the WRX need 3 shifts to 60. Most performance cars have no problems with throttle response or calibration. The stuff you speak of is more for mainstreamers, which suck anyway. Do yourself a favor and educate yourself before mashing your keyboard

      • 0 avatar
        ajla

        I have no sympathy for the person that buys a “performance oriented” vehicle AND opts for the automatic AND then complains about its behavior.

  • avatar
    Crosley

    If they can get better fuel economy from 8 speeds, fantastic. But my concern is A) is the transmission more “delicate” with the added complexity and B) is this done mainly just to satisfy ridiculous and arbitrary CAFE standards at incredible expense to the consumer.

    I honestly don’t think the average Corvette customer cars about 28 vs 29.4 mpg on the highway. You probably talking about 50 cents a month in gas, and it will likely never break “even” on the added cost it adds to the new car price.

    But you will get their attention if this new fangled 8 speed requires replacement much sooner, it’s impossible to rebuild, and a GM dealer wants $8,000 for it.

    • 0 avatar
      sportyaccordy

      Did the 6 speed prove to be “delicate”? Have the 8 speeds in other cars proved to be “delicate”? Do you know how much the new transmission will cost? How much it will add to the price of the 6AT C7? Where are you getting any of this information?

      And 28 vs 30 MPG is about $100-150 a year depending on gas prices. Not make or break but definitely more than “50 cents a month”

      I thought this was suppsed to be the Best n Brightest

    • 0 avatar
      Maymar

      I wouldn’t be shocked if they’re also doing it just to be able to one-up Porsche’s 7-speed PDK before the internet decides 6 speeds is archaic and further proof of GM’s overwhelming incompetency, and unwillingness to adapt technology developed after Sonny and Cher broke up.

      That said, as mentioned, this is destined for every RWD GM, where it can serve a bigger and more relevant benefit. But, it makes sense for GM to put that transmission to use in as many applications as is effective. And, I’d imagine the Corvette would be a decent place to roll out something like that. Between the group of owners that will in short time crank up the power, grenading it and giving GM real-world data on weak spots without having to pay out warranty claim, and in something that’s far more likely to be a second or third car, making any potential issues less likely to inspire ire and rage at being stranded.

  • avatar
    LeadHead

    I’ve heard this transmission might be based on the Aisin/Toyota/Lexus 8-speed. Anyone have any insight?

    Edit: Actually, after reading the the SAE paper, I’m almost positive this is a licensed ZF8 design. The 7.0-1 gear spread, the 5 clutches and off-axis oil pump are exactly the same as the ZF8.

    • 0 avatar
      PonchoIndian

      Typically if you license the rights to build something like this you have to say that it is a ZF unit, just like ever manufacturer who uses the ZF says.

      In this case, I’m pretty sure GM Powertrain took ideas from the ZF8 and made their own transmission. The similarity in design probably isn’t a mistake, it is probably the best way to do it. Kind of like its best to put headlights on the front of the car and tail lights on the back.

  • avatar
    Hemi

    I think a lot are missing the picture. It’s not that the Vette owner cares about MPG, it’s about having a 460hp car that gets easy 30mpg on the highway! Also not having to stop so often to get gas on long trips!

    I can’t wait to see how the new Charger RT will do with the 8 speed. Currently I can get 30mpg on the highway by keeping it around 50-58mph. Problem is I’m at almost 2k RPMs at 60mph, so my MPG drops to 25 when doing 70ish.

  • avatar
    Vulpine

    To answer the headline question, Yes–if one or two of those gears is an extra tall overdrive.

    Quite honestly, with the aerodynamics of the Corvette, it should have already exceeded the 30mpg mark years ago. That big engine doesn’t need to turn more than 1,000 rpm to idle down the freeways at 70mph+. As such, if a ’96 Camaro V6 could exceed 32mpg with a 4-speed automatic transmission, the V8 Corvette shouldn’t have any trouble doing the same.


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