Page 1 of 2 12 LastLast
Results 1 to 10 of 15
Discuss Transmissions speeds 4? 5? 6? in the alt.autos.gm forum at Car Dealer Forums; For a number or years, automatic transmissions have been mostly four speed. Now I'm seeing ...
  1. #1
    Edwin Pawlowski
    Guest

    Default Transmissions speeds 4? 5? 6?

    For a number or years, automatic transmissions have been mostly four speed.
    Now I'm seeing five and six speed, plus Nissan Maxima has a constant
    velocity on the '07 models (shades of Turboglide?)

    In theory, the more speeds the smoother acceleration and ease of staying in
    a power range of the engine. In practice though, does it really make
    difference? Any thoughts on what is "best"?
    --
    Ed
    http://pages.cthome.net/edhome/





    › See More: Transmissions speeds 4? 5? 6?

  2. #2
    William H. Bowen
    Guest

    Default Re: Transmissions speeds 4? 5? 6?

    Edwin,

    In theory, the best would be an electronically controlled CVT,
    where you have infinite ratios available and, by sensing engine load,
    throttle position, road speed, etc. get a "perfect" match of engine
    power to need, also taking into account fuel economy and emissions.

    Needless to say, such a system would be complex and expensive. I'm
    glad to see Nissan bite the bullet and try that sort of system in the
    Maxima (though I'd not want to be one of the "test subjects" to try it
    out in the real world unless they'd guarantee that transmission for
    say 150K miles).

    As far as conventional multiple speed transmissions, you have a
    trade off of added cost, complexity, the added weight of the
    additional gearsets and servos required to operate it as you increase
    the number of speeds VS the improvement in mileage and emissions the
    additional transmission gears provide. Modern electronics makes it
    easier: a silicon computer works much quicker and with less complexity
    that a hydraulic one can (electrons can move much faster than
    hydraulic oil, valves and springs).

    One real-world example I could use is to compare the operation of a
    GM 4T60 with a 4T60E (drive a 1992 Buick Regal, then try a 1993: about
    the only mechanical difference between those 2 cars is the 1992 has a
    4T60, which has no electronic control except converter clutch lockup,
    the 1993 has a 4T60E which has electronic controlled shifting) -
    gearsets and such are the same, but the 4T60E operates sooooooo much
    better. The later 4T65E better yet - even more of the hydraulic
    controls where replaced by software in the PCM.

    . Also, the "hype factor" has to be taken into consideration as well
    - all the auto makers, both foreign and domestic, are in a game of
    "keeping up with the Jonses". Those marketing folks always want new
    and better things to tout and hate the idea that they don't have what
    the other guy is offering (or maybe something even better).

    The old Chevrolet TurboGlide was a great idea conceptionally, but
    suffered in the execution due to the state of the art available in
    1958. It was highly complex internally and a real bitch to work on.
    I've always wondered if the concept might fare better given modern
    computer-aided design technology, but I still believe that CVTs are
    the wave of the future.

    Regards,
    Bill Bowen
    Sacramento, CA


    "Edwin Pawlowski" <esp@snet.net> wrote:

    >For a number or years, automatic transmissions have been mostly four speed.
    >Now I'm seeing five and six speed, plus Nissan Maxima has a constant
    >velocity on the '07 models (shades of Turboglide?)
    >
    >In theory, the more speeds the smoother acceleration and ease of staying in
    >a power range of the engine. In practice though, does it really make
    >difference? Any thoughts on what is "best"?


  3. #3
    Guest

    Default Re: Transmissions speeds 4? 5? 6?


    "William H. Bowen" <wh_bowen@sbcglobal.net> wrote in message
    news:u6tlc2lpscgks4mioadjqhu7179l5d95l1@4ax.com...
    > Edwin,
    >
    > In theory, the best would be an electronically controlled CVT,
    > where you have infinite ratios available and, by sensing engine load,
    > throttle position, road speed, etc. get a "perfect" match of engine
    > power to need, also taking into account fuel economy and emissions.


    I pretty much agree with you, Bill. Making a durable CVT is a bit of
    a challenge, but I think of it in the same light as making a durable
    4-wheel drive system. In the old days, 4-wd systems existed and were
    desirable but they wore out quickly, they used extra fuel, and needed
    a good bit of service. Now, they have largely been tamed.

    Autotrannies can get better in just the same way, and they are much
    better today than they used to be , except for the occasionally runs of
    units which have not been well developed by the manufacturers in their
    haste to market.

    My next car is going to be a manual transmission Volvo, and that
    doesnt disappoint me either. ( A new development, for me. I am coming
    out of retirement for a few years of foreign service, and this car is
    already
    leased and ready to go.) I will continue, I hope, to be able to keep in
    contact via these groups, and will let you know how it does.



  4. #4
    Mike Marlow
    Guest

    Default Re: Transmissions speeds 4? 5? 6?


    "Edwin Pawlowski" <esp@snet.net> wrote in message
    news:4pCyg.137493$dW3.36616@newssvr21.news.prodigy .com...
    > For a number or years, automatic transmissions have been mostly four

    speed.
    > Now I'm seeing five and six speed, plus Nissan Maxima has a constant
    > velocity on the '07 models (shades of Turboglide?)
    >
    > In theory, the more speeds the smoother acceleration and ease of staying

    in
    > a power range of the engine. In practice though, does it really make
    > difference? Any thoughts on what is "best"?


    The very same question ran through my mind lately Ed. The Nissan commercial
    brought it forward in my mind. CV transmissions are certainly nothing new
    and they are a pretty proven technology. I'm not sure if the technology has
    proven itself to scale up to car size applications but I suppose the Nissan
    will show whether it does or not. If I'm not mistaken, isn't there a Honda
    that uses CVT also? Seems to me that Ford tried this not so long ago also.
    It's certainly a much more simple transmission design.

    --

    -Mike-
    mmarlowREMOVE@alltel.net



  5. #5
    Mike Marlow
    Guest

    Default Re: Transmissions speeds 4? 5? 6?


    "William H. Bowen" <wh_bowen@sbcglobal.net> wrote in message
    news:u6tlc2lpscgks4mioadjqhu7179l5d95l1@4ax.com...
    > Edwin,
    >
    > In theory, the best would be an electronically controlled CVT,
    > where you have infinite ratios available and, by sensing engine load,
    > throttle position, road speed, etc. get a "perfect" match of engine
    > power to need, also taking into account fuel economy and emissions.
    >


    Let's talk about that some Bill. Since CVT is all about centrifugal force
    it is easier to keep the proper "gear ratio" simply based on the load placed
    on the engine. I'm not sure we would need as many of the electronic
    monitoring and control functions since the tranny is more self regulating
    than a multiple speed gearbox.

    I'm wondering what the thing actually looks like inside. In my imagination,
    I'm seeing this large-ish snowmobile belt humming away...

    --

    -Mike-
    mmarlowREMOVE@alltel.net



  6. #6
    Mike Hunter
    Guest

    Default Re: Transmissions speeds 4? 5? 6?

    AWD Ford 500s and Freestyles currently have a CVT tranny.

    mike hunt


    "Mike Marlow" <mmarlow@alltel.net> wrote in message
    news:c5647$44cb4887$471fb97a$25586@ALLTEL.NET...
    >

    Seems to me that Ford tried this not so long ago also.
    > It's certainly a much more simple transmission design.
    >
    > --
    >
    > -Mike-
    > mmarlowREMOVE@alltel.net
    >
    >




  7. #7
    Mike Hunter
    Guest

    Default Re: Transmissions speeds 4? 5? 6?

    High winding engines are more fuel efficient and develops more HP. The Japs
    like to advertise the HP their engine produce. The problem with that
    however is the torque band and the HP band are too far apart. It works fine
    when one has a manual tranny and uses the gears to stay on the proper torque
    band but in the US most buyer prefer automatic trannys. If one does not
    keep their foot in the throttle, the vehicle dies on the grades. That is
    why the 4 cy Camry is a dog on the grades. To improve the situation the
    answer is more gears or a CVT. Many say the 500 is under power with the
    CVT. It is not, IF driven properly. When starting out with a CVT, or
    climbing a grade, one must floor the throttle to take advantage of the
    tranny ability to stay in the torque curve. If one simply uses part
    throttle, it is like starting out in a higher gear with a manual tranny.
    The Nissan commercial is deceptive. It shows the RPMs climbing, when it
    actually would be at it peak the way the driver is driving.


    mike hunt




    "Edwin Pawlowski" <esp@snet.net> wrote in message
    news:4pCyg.137493$dW3.36616@newssvr21.news.prodigy .com...
    > For a number or years, automatic transmissions have been mostly four
    > speed. Now I'm seeing five and six speed, plus Nissan Maxima has a
    > constant velocity on the '07 models (shades of Turboglide?)
    >
    > In theory, the more speeds the smoother acceleration and ease of staying
    > in a power range of the engine. In practice though, does it really make
    > difference? Any thoughts on what is "best"?
    > --
    > Ed
    > http://pages.cthome.net/edhome/
    >




  8. #8
    Mike Hunter
    Guest

    Default Re: Transmissions speeds 4? 5? 6?

    CVTs have been around in cars for many years. The DAF used a CVT in the
    sixties. They have been around at least since the thirties, on stationary
    engines, that drive machinery. It is only recently that technology as made
    it possible to use a CVT on engines that operate at higher RPMs


    mike hunt


    "William H. Bowen" <wh_bowen@sbcglobal.net> wrote in message
    news:u6tlc2lpscgks4mioadjqhu7179l5d95l1@4ax.com...
    > Edwin,
    >
    > In theory, the best would be an electronically controlled CVT,
    > where you have infinite ratios available and, by sensing engine load,
    > throttle position, road speed, etc. get a "perfect" match of engine
    > power to need, also taking into account fuel economy and emissions.
    >
    > Needless to say, such a system would be complex and expensive. I'm
    > glad to see Nissan bite the bullet and try that sort of system in the
    > Maxima (though I'd not want to be one of the "test subjects" to try it
    > out in the real world unless they'd guarantee that transmission for
    > say 150K miles).


    > Bill Bowen
    > Sacramento, CA
    >
    >




  9. #9
    Guest

    Default Re: Transmissions speeds 4? 5? 6?


    "Mike Marlow" <mmarlow@alltel.net> wrote in message
    news:c5647$44cb4887$471fb97a$25586@ALLTEL.NET...
    >


    > The very same question ran through my mind lately Ed. The Nissan

    commercial
    > brought it forward in my mind. CV transmissions are certainly nothing new
    > and they are a pretty proven technology. I'm not sure if the technology

    has
    > proven itself to scale up to car size applications but I suppose the

    Nissan
    > will show whether it does or not. If I'm not mistaken, isn't there a

    Honda
    > that uses CVT also? Seems to me that Ford tried this not so long ago

    also.
    > It's certainly a much more simple transmission design.
    >
    > --
    >
    > -Mike-
    > mmarlowREMOVE@alltel.net


    There have been a number of CVT applications around, and Honda is one of
    them, I believe.

    One of the first designs I saw commercialized was the Dutch DAF unit, years
    ago. DAF was
    never popular over here, and the application was, IIRC, a rather low powered
    one, so I can't
    speak with any real experience to their durability.

    I am not convinced yet that they are as durable as we, as consumers, will
    want, especially
    in the higher horsepower versions. And to say that they are simple might be
    misleading as well.
    But I do think that new designs and materials will eventually evolve that
    will make them
    attractive and less of a gamble.



  10. #10
    Edwin Pawlowski
    Guest

    Default Re: Transmissions speeds 4? 5? 6?


    Thanks for the interesting replies

    > Ed
    > http://pages.cthome.net/edhome/
    >




Page 1 of 2 12 LastLast

Similar Threads

  1. ATF+4 in older transmissions
    By kmath50@gmail.com in forum rec.autos.makers.chrysler
    Replies: 4
    Last Post: 04-24-2008, 02:30 AM
  2. automatic transmissions
    By daddy in forum rec.autos.makers.chrysler
    Replies: 3
    Last Post: 05-18-2007, 07:10 PM
  3. strength of motors and transmissions?
    By houndman@phonom.net in forum alt.autos.subaru
    Replies: 9
    Last Post: 04-03-2007, 02:25 PM
  4. 07 camry transmissions?
    By Marty in forum alt.autos.toyota
    Replies: 3
    Last Post: 12-10-2006, 09:36 AM
  5. interchangeability of transmissions
    By canoe56@knology.net in forum rec.autos.makers.chrysler
    Replies: 2
    Last Post: 09-30-2006, 03:17 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •