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Lifetime MPG

Discussion in 'Gen 2 Prius Main Forum' started by speedy, May 5, 2005.

  1. speedy

    speedy New Member

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    I have had my Prius for 10 days now, and of course I love it. It's hands down the best car I've ever had.

    And I downloaded the user's guide that's suggested in the "taking delivery of a prius" guide. It mentions that you can find both your lifetime MPG and MPG for your current trip or tank of gas. I can't find the button for lifetime MPG. Any hints on where to look for that?

    Thanks.
     
    #1 speedy, May 5, 2005
  2. randalla

    randalla Member

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    Hi Speedy,

    Welcome to the world of Prius! I hope your car is meeting your expectations.

    There are a number of inaccuracies in the owner's manual with regards to features. One of them unfortunately happens to be the lifetime MPG. Hopefully, there will be a software upgrade available in the future to include that feature.
     
    #2 randalla, May 5, 2005
  3. john1701a

    john1701a Prius Guru

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    <div class='quotetop'>QUOTE(randalla\";p=\"87218)</div>
    I don't.

    Sorry to be blunt, but when you reach the mileage I'm at, you'll discover the curse that wish would bring... The margin-of-error (1.4 MPG) is greater than the annual variance, making a display lifetime value pretty much worthless and definitely misleading.

    Looking at these year #2 graphs for both my Prius, it becomes obvious. Notice what doesn't happen to the green line.

    http://john1701a.com/prius/prius-data04.htm

    http://john1701a.com/prius/prius-data13.htm

    Then note how it gets even worse as the year's progress.
     
    #3 john1701a, May 5, 2005
  4. exhuman

    exhuman Member

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    I'm not sure I follow what you're saying about the 1.4 mpg margin of error and the annual variance. I know I wasn't a good statistics student, tho'.

    Do you mean that after a year or 2 the Lifetime MPG becomes close to a straight line but that it's y-coordinate is deceptive in that the margin of error is 1.4 mpg?

    I know for me the lifetime average would be a source of frustration. Like the poor person who tries to make up in one semester what 3 years of partying did to his GPA. (just anecdotal, not personal experience :roll: ) After a few years, you could drive like that guy who went over 1000 miles at 35 mph and still not get your Lifetime average to budge.

    I hope I haven't added more confusion to the confusion.
     
    #4 exhuman, May 5, 2005
  5. john1701a

    john1701a Prius Guru

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    Margin-of-Error is the difference between DISPLAYED and CALCULATED values. The Multi-Display rounds optimistically. So we know for a fact that it will read higher than actual.

    And yes, it becomes a flat line after awhile... which varies less than 1 MPG.

    So rarely ever seeing a change and realizing that it isn't entirely accurate anyway would be very frustrating.
     
    #5 john1701a, May 5, 2005
  6. Spidey126

    Spidey126 New Member

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    does this apply to the 2010 model as it has changed?
     
    #6 Spidey126, May 11, 2009
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