Page 1 of 8 123 ... LastLast
Results 1 to 10 of 80

Thread: Is the CVT really more efficient than the manual transmission?

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. #1
    Junior Member
    Join Date
    Dec 2016
    Location
    Canada
    Country
    Canada
    Posts
    17
    Garage empty: add car
    Thanks
    1
    Thanked 4 Times in 4 Posts

    Is the CVT really more efficient than the manual transmission?

    The EPA ratings say the CVT gets better mileage than the manual, but some users here have tested both and achieved better MPG with the manual. But, those tests were performed by skilled eco drivers using the most fuel efficient driving possible.

    In terms of regular daily driving which may occasionally require going fast, which one wins? Will the manual only win if the driver really focuses on driving efficiently? Which one gets better highway mileage at 100km/h?

  2. The Following User Says Thank You to ecoboxer For This Useful Post:

    18slcmirage (11-20-2020)

  3. #2
    Senior Member IchabodCrane's Avatar
    Join Date
    Apr 2014
    Location
    Thunder Bay, ON. CA
    Country
    Canada
    Posts
    726
    Thanks
    57
    Thanked 317 Times in 191 Posts
    In normal "every man" driving the CVT is likely more efficient.
    With skilled eco driving in mixed conditions mostly non highway the manual likely wins..
    Mixed conditions mostly highway probably pretty close.
    Will weld for beer.

        __________________________________________

        click to view fuel log View my fuel log 2014 Mirage SE 1.2 automatic: 45.3 mpg (US) ... 19.3 km/L ... 5.2 L/100 km ... 54.5 mpg (Imp)


  4. #3
    Administrator Daox's Avatar
    Join Date
    Jan 2013
    Location
    Germantown, WI
    Country
    United States
    Posts
    4,999
    Thanks
    2,892
    Thanked 1,804 Times in 1,017 Posts
    My bet goes to the 5 speed manual in both conditions. Here is why:

    Speed vs. mpg/mileage/fuel economy chart - Mirage 1.2L 5-spd and CVT

    and

    Gas mileage/MPG test: 2014 Mirage CVT vs. 5-speed (sub/urban Ottawa route)

    That being said, the difference isn't gigantic. If you like the convenience of the CVT, you're going to take a hit, but its not the end of the world.
    Custom Mirage products: Cruise control kit, Glove box light, MAF sensor housing, Rear sway bar, Upper grill block

    Current project: DIY Nitrous oxide setup for ~$100

        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage DE 1.2 manual: 47.2 mpg (US) ... 20.1 km/L ... 5.0 L/100 km ... 56.7 mpg (Imp)


  5. #4
    Senior Member IchabodCrane's Avatar
    Join Date
    Apr 2014
    Location
    Thunder Bay, ON. CA
    Country
    Canada
    Posts
    726
    Thanks
    57
    Thanked 317 Times in 191 Posts
    Quote Originally Posted by Daox View Post
    My bet goes to the 5 speed manual in both conditions. Here is why:

    Speed vs. mpg/mileage/fuel economy chart - Mirage 1.2L 5-spd and CVT

    and

    Gas mileage/MPG test: 2014 Mirage CVT vs. 5-speed (sub/urban Ottawa route)

    That being said, the difference isn't gigantic. If you like the convenience of the CVT, you're going to take a hit, but its not the end of the world.
    in the third chart there are no data points for speeds below 50mph shown with cvt and at the top of the chart (highest speeds) there would have to be an error or the Philippines spec manual has different gears than US spec as it's a proven fact that US spec cvt runs almost 1000rpm lower than US spec manual at or above 60mph.
    I have personally achieved 3.3L/100km at speeds varying from 45mph to 60mph with my '14 cvt. my '17 cvt is proving to be even more aggressive, holding as low as 1200rpm at 30mph, 1500 @45mph and 2100 @ 60mph..
    I haven't tried to achieve 3.3L/100km again in the '17 yet as I bought it in late fall and could not match conditions. Will try in spring on dry roads @ 10 to 20°C and see what happens.
    I got these numbers by maintaining 2000rpm regardless of speed/location/condition. With more agressive techniques the cvt should hold it's own vs manual trans US spec vs US spec.
    Last edited by IchabodCrane; 01-21-2017 at 01:56 AM.
    Will weld for beer.

        __________________________________________

        click to view fuel log View my fuel log 2014 Mirage SE 1.2 automatic: 45.3 mpg (US) ... 19.3 km/L ... 5.2 L/100 km ... 54.5 mpg (Imp)


  6. #5
    Junior Member
    Join Date
    Dec 2016
    Location
    Canada
    Country
    Canada
    Posts
    17
    Garage empty: add car
    Thanks
    1
    Thanked 4 Times in 4 Posts
    Quote Originally Posted by Daox View Post
    My bet goes to the 5 speed manual in both conditions. Here is why:

    Speed vs. mpg/mileage/fuel economy chart - Mirage 1.2L 5-spd and CVT

    and

    Gas mileage/MPG test: 2014 Mirage CVT vs. 5-speed (sub/urban Ottawa route)

    That being said, the difference isn't gigantic. If you like the convenience of the CVT, you're going to take a hit, but its not the end of the world.
    What's confusing me here is that, in theory, the CVT can do any gear ratio the manual can, and more. How is it then that the manual is getting better MPG at 120km/h?

  7. #6
    Moderator Eggman's Avatar
    Join Date
    Sep 2015
    Location
    Cleveland, Ohio
    Country
    United States
    Posts
    10,156
    Thanks
    4,039
    Thanked 2,788 Times in 2,107 Posts
    Quote Originally Posted by ecoboxer View Post
    What's confusing me here is that, in theory, the CVT can do any gear ratio the manual can, and more. How is it then that the manual is getting better MPG at 120km/h?
    That's a good question.
    1. The CVT still has a torque converter (aka slushbox)?
    2. The operator of a manual transmission controls the shift points, either for better or worse fuel economy.
    3. The data do not take into account speed.

    Just tossing out some ideas. I think MetroMPG, Daox, and others more versed in hypermiling can give better answers.

        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage ES 1.2 manual: 49.6 mpg (US) ... 21.1 km/L ... 4.7 L/100 km ... 59.5 mpg (Imp)


  8. #7
    Senior Member IchabodCrane's Avatar
    Join Date
    Apr 2014
    Location
    Thunder Bay, ON. CA
    Country
    Canada
    Posts
    726
    Thanks
    57
    Thanked 317 Times in 191 Posts
    Quote Originally Posted by Eggman View Post
    That's a good question.
    1. The CVT still has a torque converter (aka slushbox)?
    the torque coverter plays virtually no role in mileage numbers as it only comes into play starting from a dead stop and locks up almost immediately upon moving. This small slippage cycle would roughly equal the slippage/engagement cycle of starting from stop of the manual transmission.
    After this the torque converter stays locked throughout all gear ratios on the spectrum except possibly during the reduced power moment of shift from low to high aux gearbox.
    The manual gearbox has to absorb 4 shift points through it's range so theoretically should waste more energy between 1st and 5th gears going up and coming down.
    It seems theoretical and real world are not that tightly linked when it comes to driving..
    Will weld for beer.

        __________________________________________

        click to view fuel log View my fuel log 2014 Mirage SE 1.2 automatic: 45.3 mpg (US) ... 19.3 km/L ... 5.2 L/100 km ... 54.5 mpg (Imp)


  9. #8
    Senior Member IchabodCrane's Avatar
    Join Date
    Apr 2014
    Location
    Thunder Bay, ON. CA
    Country
    Canada
    Posts
    726
    Thanks
    57
    Thanked 317 Times in 191 Posts
    Quote Originally Posted by ecoboxer View Post
    What's confusing me here is that, in theory, the CVT can do any gear ratio the manual can, and more. How is it then that the manual is getting better MPG at 120km/h?
    the answer to this question is in the car specs. The graph is showing a Philippines spec. gearbox vs a US spec CVT.
    The difference being the Phillippine spec manual has higher gearing than the US spec allowing it to run lower RPM at high speed than a US spec manual.
    I don't know if all CVT's are the same or are ratios different in different markets?
    Will weld for beer.

        __________________________________________

        click to view fuel log View my fuel log 2014 Mirage SE 1.2 automatic: 45.3 mpg (US) ... 19.3 km/L ... 5.2 L/100 km ... 54.5 mpg (Imp)


  10. #9
    Junior Member
    Join Date
    Dec 2016
    Location
    Canada
    Country
    Canada
    Posts
    17
    Garage empty: add car
    Thanks
    1
    Thanked 4 Times in 4 Posts
    Quote Originally Posted by Eggman View Post
    That's a good question.
    1. The CVT still has a torque converter (aka slushbox)?
    2. The operator of a manual transmission controls the shift points, either for better or worse fuel economy.
    I don't think these would come into play when driving a constant speed on the highway. Torque converters do lock up at high speeds, they really only unlock to prevent the engine from stalling when stopped.

    Quote Originally Posted by IchabodCrane View Post
    the answer to this question is in the car specs. The graph is showing a Philippines spec. gearbox vs a US spec CVT.
    The difference being the Phillippine spec manual has higher gearing than the US spec allowing it to run lower RPM at high speed than a US spec manual.
    I don't know if all CVT's are the same or are ratios different in different markets?
    Interesting, I see now that there are two seperate manual gearboxes for different regions of the world.

    Can anyone with the US 5 speed manual confirm what MPG they are able to achieve at highway speeds in 5th gear?

    It still doesn't make sense to me that the 5 speed would get better mileage when it revs at such a higher RPM on the highway. I always assumed that lower RPM = lower fuel consumption because of reduced friction.

  11. #10
    Senior Member MightyMirageMpg's Avatar
    Join Date
    Apr 2016
    Location
    wi
    Country
    United States
    Posts
    760
    Thanks
    457
    Thanked 318 Times in 203 Posts
    Quote Originally Posted by ecoboxer View Post

    Can anyone with the US 5 speed manual confirm what MPG they are able to achieve at highway speeds in 5th gear?

    It still doesn't make sense to me that the 5 speed would get better mileage when it revs at such a higher RPM on the highway. I always assumed that lower RPM = lower fuel consumption because of reduced friction.
    MPG's fluctuate so heavily based on conditions and driver its almost insignificant to put a number out.

    The automatic achieves lower RPMs but also consumes lots of power itself to operate. Making it drastically less efficient than any manual offered in a mirage. The effects would be shown in city driving, with The auto loosing to the stick.

    But because the auto transmission allows such a low final drive (.54 ideal as stated by INUVIK) it allows the engine to spin drastically slower speed then the manual and therefore the engine itself consumes less fuel, (but it's still being robbed of the cvt draw)

    At some point, the amount of fuel lost by excess RPM exceeds the fuel lost by the draw of the CVT. For your "average" driver that doesn't employ tricks or techniques to save fuel, the speed is probably about 65mph, where the cvt begins to get better MPG

    There's a little more to be discussed but simply put I've not seen any data that referenced engine load at speed manual vs automatic, and unless you have a lot of patience and the fuel map for the car... The data is useless anyways.

    Hopefully i explained that well enough its hard to explain in text
    Last edited by MightyMirageMpg; 01-22-2017 at 09:41 PM.

  12. The Following User Says Thank You to MightyMirageMpg For This Useful Post:

    MetroMPG (02-16-2017)

Posting Permissions

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