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MPG better than what the computer calculated

Discussion in 'Gen 3 Prius Fuel Economy' started by PSD Prius, Apr 9, 2011.

  1. PSD Prius

    PSD Prius Junior Member

    Joined:
    Feb 20, 2011
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    Location:
    Yuba city
    Vehicle:
    2011 Prius
    Model:
    Three
    Hi everyone. Today I filled up and calculated my MPG to be 51.9 for the whole tank. My computer calculated by MPG to be 51.7. This is a first for me. That is all for now.

    Thanks
     
    #1 PSD Prius, Apr 9, 2011
  2. krelborne

    krelborne New Member

    Joined:
    Feb 2, 2011
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    Location:
    Alabama
    Vehicle:
    2010 Prius
    Model:
    II
    How many gallons did you put in? I had a similar experience, but I think the pump cut off too soon. If your next calculated tank seems lower than normal, that may be what happened.
     
    #2 krelborne, Apr 9, 2011
  3. PSD Prius

    PSD Prius Junior Member

    Joined:
    Feb 20, 2011
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    Location:
    Yuba city
    Vehicle:
    2011 Prius
    Model:
    Three
    I put in 9.62 gals. And that was after filling up slow, and filling up to the 2nd shut off click. If I had stopped fueling after the first shut off click, my MPG's would be higher.
     
    #3 PSD Prius, Apr 9, 2011
  4. pakitt

    pakitt Senior Member

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    Location:
    Colorado
    Vehicle:
    2021 Prius Prime
    Model:
    Limited
    It happened to me only once (-1%).
    The average error I have is 6% and very few times I have had less than 3% error. It also depends on how much fuel I get in, before the first stop (and that depends on the speed at which the fuel gets hosed in the tank) and how much is the error at the pump itself.
    But "negative" error, just once in almost 2 years of ownership.
     
    #4 pakitt, Apr 10, 2011
  5. alfon

    alfon Senior Member

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    Location:
    seaside, oregon
    Vehicle:
    2010 Prius
    Model:
    III
    The only way to really get a 100% true calculated mpg is to..

    Fill up your tank to the top, so you can not put one more drop of
    gas in or it will spill on the ground.

    Next drive 400-550 miles or so. Than fill up at the same station,use the same gas pump, and fill up again to the top so you can not put another drop of gas in or it would spill on the ground.

    This is the only true way, no guess work, just your true mpg.
    Now, compare your true mpg to your computer generated mpg.


    al
     
    #5 alfon, Apr 10, 2011
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