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Lifetime MPG?

Discussion in 'Gen 2 Prius Main Forum' started by majordude, May 25, 2005.

  1. majordude

    majordude Member

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    Other than a pad of paper and a calulator, how are you guys figuring your lifetime MPG?

    :?:

    Is there a running total somewhere twenty menus below the main screen?

    I only see the one that starts and stops with each tank of fuel (it can be reset at any time as well).

    THANKS!
     
  2. Frank Hudon

    Frank Hudon Senior Member

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    on the 2k4-5 pen and paper (computer spread sheet) is the only way. Classic Prius just don't reset it.
     
  3. john1701a

    john1701a Prius Guru

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    On paper is the only method... even if there was one showing on a screen, since the computer only provides an approximation.

    The difference between paper & computer averages to about 1.4 MPG.

    In other words, once you surpass about 15,000 miles of data, the margin-of-error makes a displayed lifetime value too inaccurate to be considered a valid representation of actual performance.

    Note that mine has been within that 1.4 MPG difference for an entire year now (over 21,000 miles).
     
  4. john1701a

    john1701a Prius Guru

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    Actually, the Classic reset too... every 10,000 miles rather than after every fill up.
     
  5. Frank Hudon

    Frank Hudon Senior Member

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    after every 10,000 KM's as well. I've never reset mine and after 16000+km's it's just dropped from 5.3 to 5.2Liter per hundred km's on my way home from Lacey Washington 2 weekends ago. It's averaging about 1.8 miles per gallon Hi for me as well and it tracts pretty close to the calculated to be what I consider fairly accurate.
     
  6. vincent1449p

    vincent1449p Active Member

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    I don't think the Lifetime is reset. The distance travelled may be rolling over 9999 due to the display can only show 4 digits but the Lifetime remains.

    On my Classic, I 've never reset after 40,000 km. If the Lifetime were to reset every 10,000 km, then I should see acute changes every 10,000 km on the MFD. This is because my tank-to-tank may be less than 4.0 l/100km, but the MFD does not seem to change much.

    According to my spreadsheet, I 'm seeing about 0.3 l/100km or about 4 MPG difference. Maybe I'm in a warmer climate?

    Vincent
     
  7. Frank Hudon

    Frank Hudon Senior Member

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    Vincent your probably right on the cumulative data but the readout resets every 10,000 km/6000 mile (approx) but it's interesting that the car's with readouts in miles go roughly 12,000 Kms before resetting. Computer programming glitch?
     
  8. MB in Brooklyn

    MB in Brooklyn New Member

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    Toyota should make the software so that the touchscreen system calculates mpg with all three odometer numbers (trip a, trip b, and total). In other words, allow Prius owners to toggle between MPG for car lifetime (non-resetable odometer) plus the two resetable trip odometers (such as one to be used per tank, and the other perhaps per a particular trip). All of this could easily be integrated into the programming.
     
  9. Frank Hudon

    Frank Hudon Senior Member

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    <div class='quotetop'>QUOTE(MB in Brooklyn\";p=\"92807)</div>
    this would be ideal. now to convince them. maybe a software patch. The car knows all three readings so why then couldn't it calculate from any base input, A,B, total. About time for someone to reverse engineer the software and get on making money giving people what they want.
     
  10. Tideland Prius

    Tideland Prius Moderator of the North
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    That's a good idea!
     
  11. john1701a

    john1701a Prius Guru

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    <div class='quotetop'>QUOTE(MB in Brooklyn\";p=\"92807)</div>
    The decision was made to keep things simple intially. And despite that, Prius still has a minor stigma anyway for being a dream-come-true for techies.

    There's a whole bunch of stuff they could have made the Multi-Display display. Lots of data flows through the system. (It's pretty sweet if you ever get to see a scanner in action.)

    As for the Lifetime MPG value, the "flat line" effect still holds true no matter where you see it. You can go for months without even a 0.1 change.