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Less miles per tank but MPG same

Discussion in 'Gen 2 Prius Fuel Economy' started by Joe Brown, Nov 19, 2015.

  1. Joe Brown

    Joe Brown Junior Member

    Joined:
    Oct 18, 2012
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    2007 Prius
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    II
    In the last month, I've been getting less miles per fill up. Previously the gas light would hit 1 bar around 400 miles. Now its hitting 1 bar around 350-360 miles. But when I fill up, I only fill up about 8 gallons so I haven't lost any gas mileage. It feels as if the tank shrunk on me. Anyone else experience this?
     
    #1 Joe Brown, Nov 19, 2015
  2. jtegf

    jtegf Junior Member

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    Yes! Exactly what you stated. The internal bladder in the fuel tank shrinks a bit or stiffens when the temperatures drop this time of year. Therefore, your system holds a bit less fuel. I've not heard of any experiments to try and precisely correlate volume lost to ambient temps but over the last 8 winters, my sense of the thing in my Gen 2 is that I'm losing about a gallon storage volume at a 40-50 degree F. drop from our normal summertime highs of 95-100 here in Texas to wintertime lows of 30-45.
     
    #2 jtegf, Nov 19, 2015
  3. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    Yes all the gen2 (2004-2009) in North America have flexible bladder which gets less flexible in cold weather, try afternoon fill ups.
     
    #3 JimboPalmer, Nov 19, 2015
  4. fuzzy1

    fuzzy1 Senior Member

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    But his profile shows a Gen 1, not a Gen 2. It should not have that bladder.
     
    #4 fuzzy1, Nov 19, 2015
  5. Joe Brown

    Joe Brown Junior Member

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    Thanks, I just updated my profile. I do have a gen 2. sorry for the confusion and thanks for the explanation.
     
    #5 Joe Brown, Nov 19, 2015
  6. wjtracy

    wjtracy Senior Member

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    Def we are now on one pip at 47 MPG and 350 miles...
    seems to violate basic math
     
    #6 wjtracy, Nov 19, 2015
  7. trungdok

    trungdok Junior Member

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    #7 trungdok, Dec 2, 2015
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