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How to calculate MPG over 99.9 using the Eco Savings screen

Discussion in 'Prius c Fuel Economy' started by ufourya, Sep 26, 2014.

  1. ufourya

    ufourya We the People

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    115 MPG.jpg

    Fuel cost entered as $3.20. To arrive at an internally consistent MPG figure, divide $3.20 by $.37 and multiply the result, 8.648, by 13.3 miles and arrive at 115 MPG. This is, of course, a small sample size and will be somewhat inaccurate. The larger the sample, the more accurate the figure becomes.

    We all know that the computer figures are somewhat optimistic, but this is internally consistent and may be used for all the contests and challenges that measure MPGs here on Prius Chat.

    This little run began and ended at the same spot. The car is capable of some amazing stuff.
     
    minkus and SageBrush like this.
  2. ztanos

    ztanos All-around Geek!

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    Why 8.648? Brain isn't working
     
  3. bisco

    bisco cookie crumbler

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    it's the result of the division of cost per gallon by fuel cost.
     
  4. SageBrush

    SageBrush Senior Member

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    MPG = miles per gallon = miles DIVIDED BY gallons = miles TIMES (1/gallons)

    miles = 13.3
    gallons = 37/320 = 0.115625
    1/gallons = 320/37 = 8.6486

    MPG = 13.3/0.115625 = 13.3*8.6486
    ---
    Briefly,
    x/y = x * (1/y)
     
    #4 SageBrush, Sep 26, 2014
    Last edited: Sep 26, 2014
  5. ztanos

    ztanos All-around Geek!

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    Okay, so his gallons refueled were 8.6486? Got it. I figured that's what it was, but it wasn't clear.
     
  6. SageBrush

    SageBrush Senior Member

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    (1/gallons) refueled was 8.6486
     
  7. ztanos

    ztanos All-around Geek!

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    Yep.... I got it now... like I said... I was impressed he used 8.6486 gallons after only a few miles according to his picture.
     
  8. ufourya

    ufourya We the People

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    Is it possible this has become too complicated? Let us say that fuel at the pump was $3.20 and entered as such into the computer, either at fuel up if you are fast enough or on the settings screen.

    Let us say that you choose to keep track of a run on trip meter 'B', so you zero it out.

    Let us say that you drive until the Eco Savings screen indicates you have used $.32 listed as 'fuel cost B'. You have now used 1/10 gallon of fuel. 3.20/.32 = 10

    You look at the number of miles driven and multiply that by 10 to arrive at MPG. Same thing for any other furl cost number. OK?

    IMG_3812.JPG

    3.20/20.81 = .1538. .1538 x 408.8 = 62.87 or 62.9

    Oh, WAIT ! I like Sage Brush's explanation better.
     
    #8 ufourya, Sep 30, 2014
    Last edited: Sep 30, 2014
  9. ztanos

    ztanos All-around Geek!

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    It wasn't complicated. I made it complicated because your picture showed 13.3 miles and I couldn't for the life of me figure out how you used 8+ gallons of fuel after only driving 13 miles.
     
  10. SageBrush

    SageBrush Senior Member

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    :)

    Not everybody drives like a snail, you know.
     
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  11. ufourya

    ufourya We the People

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    I don't drive like a snail all the time, just for the fun of it to explore the car's capabilities. If you think that I used over 8 gallons to drive 13.3 miles, you still misunderstand the concept. :)
     
  12. SageBrush

    SageBrush Senior Member

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    A joke, my friends :)
    From someone who routinely *does* drive like a snail
     
  13. ufourya

    ufourya We the People

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    For the *very* few persons who will be interested, I have posted a series of You Tube videos showing how the car managed 119 MPG. over a short loop.

    Just search ufourya22.

    Here is the last one:

     
  14. SageBrush

    SageBrush Senior Member

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    ^^ Your car has good acoustics too ;)