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Outside temp affects already calculate MPG avg?

Discussion in 'Gen 2 Prius Fuel Economy' started by valand_krisban, Jan 12, 2006.

  1. valand_krisban

    valand_krisban New Member

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    Here's a scenario that I ran into this morning. Has anyone experienced something similar?

    Scenario:
    Filled up with gas
    The Avg MPG reset
    Drove home 26 miles at ~39 degrees F
    Avg MPG was 47.9
    Car sat for the night
    Next morning, poered on the car at ~28 degrees F
    The avg MPG immediately showed 42.3

    The car did not move all night, so how could the average just change?

    Does the outside temp directly affect pre-calculated avg MPG? If so, it really isn't an Avg over a tank of gas, it's a dynamic "snapshot in time" (now) avg.
     
    #1 valand_krisban, Jan 12, 2006
  2. efusco

    efusco Moderator Emeritus
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    No, if your car ran even for a moment before you shut it off after looking at the mileage or for a moment before you looked the next morning it'll affect the mileage with that few miles on the tank. It's very sensitive to changes that early on. I'll level out over the tank.
     
    #2 efusco, Jan 12, 2006
  3. valand_krisban

    valand_krisban New Member

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    Got it.

    Thanks!
     
    #3 valand_krisban, Jan 12, 2006
  4. hdrygas

    hdrygas New Member

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    Too further bum you out look at the number of bars on your battery before and after you shut it off. Not only is gas leaking out, but electricity is as well! If they combine your car and house is going up in flames!!! I have talked to Belle and she has promised not to do #1 and #2 at the same time!
     
    #4 hdrygas, Jan 12, 2006
  5. windstrings

    windstrings Certified Prius Breeder

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    I'm not sure about that... before you shut it off, the batt has been charged by the ICE, once you shut it off the voltage falls to its static volts and starts getting cold.

    Even on a normal car while viewing a volt meter, the regular 12V battery would "appear" more charged immediately after running, verses sitting all night.

    I'm not sure how the pruis batt monitor works, but if its all about voltage, its very misleading... its tough to tell true "capacity" of a battery without doing an amp load test on it.... I would guess that guage is not too accurate.

    It is normal for NiMH batteries to loose 2 - 4% a day from poor shelf life.... in other words... yes it leaks... but its negligable. I bet if it sat for a month, you would really notice a difference. But Until we get large capacity LiIon we are stuck.

    The main advantage of the battery in the prius is not how much it can store..... its more about juggleing the energy minute by minute as it negotiates wasted energy from kinetic motion, ie: coasting, speeding, stopping, starting etc.....
     
    #5 windstrings, Jan 13, 2006
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