CVT gearboxes, how are they different from normal automatic gearboxes

With CVT gearboxes becoming a common feature on most cars that are being imported into Sri Lanka, specially after Toyota Japan has made it standard for all the common models (Axio, Allion, Premio, RAV4, etc).  However a lot seem unclear what is different from the CVT, specially since Toyota went to great lengths making many changes to the implementation of the CVT in Toyota’s to make it look and feel like a normal auto, hiding some of the characteristics that easily enabled a driver to know if the car had a CVT or not.

This tweaking has made many feel that CVT gearboxes are just like auto boxes, when in reality they are engineered very differently. A simple and quick guide that i would like to point out to people is http://cars.about.com/od/thingsyouneedtoknow/a/CVT.htm.  Hits the key points straight on such as the characteristics of a true CVT gearbox, and how manufacturers tweak it to hide the characteristics since most automatic users feel not comfortable with the normal jerky revy nature of the CVT gear ratio changes.

Important to note in CVT’s are,

1. There is no physical gear ratios, which in some ways makes it feel like a manual

2. The tiptronic buttons that say 5-speed, 7-speed simply are programing (software) implementation of ratios that gets applied as you change them, unlike in a true auto where it shifts into a different gear ratio

3. Though ATF oil was used in the past, issues faced by Honda with their CVT gearboxes and by Nissan in recent times have made auto makers develop a different gearbox / transmission fluid for CVT implementation.  However the gearbox itself has gone through changes, such as torque converters which were not used in early CVT gearboxes to reduce the loss in efficiency (some say 10%) were reintroduced, and the findings that the CVT gearboxes generated more heat has seen coolers being installed to maintain temperatures.  Hence the continued need for a higher cost CVT fluid maybe more marketing than fact, but with gearbox prices being high nobody wants to skimp to prove this 🙂

4. Implementations of the CVT gearboxes differ from manufacturer to manufacture, both in the physical as well as software.  Honda implementations seem to favor retaining the revvy nature of the CVT, as Honda owners feel they are driving something sporty.  However Toyota findings that their buyers preferred the automatics more smoother controlled changes has seen Toyota invest greatly to make the CVT gearbox mimic an auto.  Nissan one of the pioneer CVT implementers and a company that actually started using it in larger cars has never got much of the spotlight though they have many different variations of CVT.

However with the emergence of the dual clutch automatic gearboxes, which has shown that cars equipped with it could shift faster than a manual gearbox has made the CVT the second best auto implementation compared to the manual.  Dual clutch implementations are featured in many European cars, with VW group even having it on their cheap small cars such as the Polo. Sadly not seen much on this from the usual Japanese cars and companies.

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6 thoughts on “CVT gearboxes, how are they different from normal automatic gearboxes”

  1. Hi,
    I am using Honda Fit GD1 2007. I changed CVTF accordingly but suddenly after 100 km after new CVTF change, after a long trip in a day about 300 km (I had to drive my vehicle in flooded ares at kaduwela few months ago), there was a kind of a jerk. It happens occasionally especially when I try to pickup pressing the accelerator heavier. If I push the accelerator softly, things look normal. What is the issue? CVT issue or a sensor issue due to driving in flooded areas?
    What is the solution?
    If it is a CVT issue, how to use that oil extreme?

  2. i have problem with my honda airwave 2007 model cvt gearbox.the driv show when the gear is in parking mode and the car does not advance in drive mode. now i need to purchase one cvt gearbox for the car.please inform me where i can buy it and how cost have to pai
    thanking you
    shahadat hoaasin
    shahadat10@gmail.com

    1. Hi, assume you are living in Sri Lanka. In which case the used spare shops delkanda (past nugegoda) are your best bet. The next is the spare part shops in Kurunegala. Finding spares for the Airwave can be harder, as it was discontinued in 2008, mainly because the GD1 range had long gone. Sadly the new Fit Shuttle look horrible compared to the Airwave. I am not quite sure, but the last generation GD series Fit Gearbox or the Fit Aria gearbox might be the same as the Airwave.

      Have you tried the Honda Upul guy? He has some experience sorting out the CVT gearbox and unlike the agent is willing to open the gearbox.

  3. Hi,

    Im having a CIVIC ES1, recently I observed that there is some vibration when the vehicle moves forward after stopping in a traffic queue or similar.. also… there is some vibration when I drive up alone mountains putting the gear wheel into “L”.. Please advice me on required action.

    Thanks…

  4. Dear sir or Madam,

    Sir m name is zeeshan from pakistan i want cvtf gearoil
    transmission fluid honda please tell me price of cvtf & which buyer provide me cvtf.

    Best Regards,
    Zeeshan

  5. Dear Sir,
    I m pranav patil, student of second year mechanical engineering.
    I m with my group participating in SAE BAJA event.
    in that we are thinking to use cvt gear box for transmission for our vehicle (buggie).
    so, i request you if you can please can you tell me disadvantages of cvt gearbox for off road buggies. and also tell me about the dealers of cvt gearbox in India.
    Thank you.
    yours faithfully
    Pranav Patil

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