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Has anyone tried this......

Discussion in 'Gen 3 Prius Fuel Economy' started by alfon, Jul 22, 2010.

  1. alfon

    alfon Senior Member

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    We all know that the computer readout for MPG is usually off by 2-4 MPG fairly consistently.

    Has anyone tried a tank of fuel just in ECO mode, than in reg mode, and lastly in Power Mode.

    Than calculate the MPG differences in each. I wonder if one mode the MPG computer is more accurate than the other.

    I would try it but the Prius is my wifes car and she probably wouldn't let me have it long enough.

    alfon
     
    #1 alfon, Jul 22, 2010
  2. GBC_Texas_Prius

    GBC_Texas_Prius Member

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    The problem with such an experiment is that it's impossible to fill the tank to the exact same level.

    On fuelly, I always record the computer readout in the notes section. When I look over the notes and compare to actual, I assume the readout error variation is due to not filling to the same level.

    Having said that and putting my engineer and software hat on, I can't imagine why the error would change with mode, but I've make assumptions before and been wrong.
     
    #2 GBC_Texas_Prius, Jul 22, 2010
  3. adamace1

    adamace1 Senior Member

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    I know the MFD is off by 3-5% every tank i have had, all 53 of them. Has nothing to do with filling up, I'm always 3-5% lower than the MFD, if it had to do with the fill up amount my mpg would be lower then higher. I'm alwasy lower than the MFD.
     
    #3 adamace1, Jul 22, 2010
  4. Tideland Prius

    Tideland Prius Moderator of the North
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    Makes no difference. I have plenty of tanks that are entirely in ECO or normal mode and they were all over the place in terms of mpg difference. My worst and best difference were in ECO mode lol.
     
    #4 Tideland Prius, Jul 22, 2010
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