Why don't car manufacturers make seven speed manual transmissions?

the only ones I know that made them have been in the Corvette, porsche 911 or 718 and some aston martin. Wouldn't it be better for acceleration and fuel economy if manual transmissions were to have a seven speed rather than a five or six speed.

15 Answers

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  • Will
    Lv 7
    5 months ago

    Since many have already said what needed to be explained, I'm just gonna save my time and say that it's just not practical. If it were, it would be the norm.

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  • Neil
    Lv 7
    5 months ago

    There are a few reasons.

    The purpose of a wide spread of gears is efficiency over a wide range of speeds. The type of customer that regularly achieves very high speeds - those that regularly cruise the German Autobahnen - tends to choose an automated transmission over a manual. Those that choose manuals tend also to choose slower cars, so there is simply less need for a wide spread of gears, so a smaller number of gears can cover the required spread.

    The purpose of more speeds is increased efficiency, but only if the shift times can be kept short. Each delay in shifting is an efficiency loss. With certain automated transmission, either a double-clutch or a more traditional epicyclic torque-converter auto, shift times are short, so shifting losses are low. With a manual, the shift time is down to the driver, and is often relatively slow, so the shifting losses start to outweigh the efficiency gains of more speeds, whether you are measuring fuel consumption or acceleration times.

    The choice of manual over automatic is often down to cost. Each extra speed adds cost, reducing the reason for choosing a manual.

    There is limited space in the gear selector mechanism for adding extra gears. Putting more gears in the limited movement of the lever makes correct gear selection more difficult, which both reduces efficiency, and reduces driver satisfaction.

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  • JetDoc
    Lv 7
    5 months ago

    My truck has an EIGHT speed transmission. Does that mean it's better than a Corvette or Porsche?

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  • 5 months ago

    Five is plenty. (Six shift positions, including reverse. Nice and handy.)

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  • don r
    Lv 7
    5 months ago

    The narrower the engine power band, the more speed transmission you need for the vehicle to be efficient.

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  • bo
    Lv 7
    5 months ago

    over the last several years the standards haven't been selling like the use to and automatics might be getting better mileage . ford now has a ten speed out most of the other manufacturers will be thre soon. even UPS has gotten out of standards and use automatics in the vans that they use to do the local deliveries. even some of the big rigs you see on the road might be an automatic

    Source(s): transmission man
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  • Ron
    Lv 7
    5 months ago

    There was a time I had to shift far more than that to get to top gear and that because of my job. Only a moron wants to do that in a car on a regular basis.

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  • Murzy
    Lv 7
    5 months ago

    You are right but manual cars don't sell very well.

  • 5 months ago

    Manufacturers make what they think will sell at an acceptable price. With seven speeds you will be shifting every minute.

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  • 5 months ago

    Doesn't Mercedes have a 10 speed transmission? The reason is that the transmissions become more expensive and harder to manufacture and repair, the more gears they have.

    • don r
      Lv 7
      5 months agoReport

      If you can make it complicated, why make it simple?

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