Effect of temperature on fuel bladder.

Discussion in 'Gen 2 Prius Technical Discussion' started by JayGoldstein, May 15, 2008.

  1. JayGoldstein

    JayGoldstein Member

    Joined:
    Aug 3, 2006
    120
    3
    0
    Location:
    Winnipeg, Manitoba, Canada
    Vehicle:
    Other Hybrid
    Model:
    N/A
    Is anyone seen any data quantifying the effect of ambient temperature on the capacity of the Prius' fuel bladder?

    E.g., what is the maximum capacity at -20C as compared with, say, 0C or +20C?
     
  2. qbee42

    qbee42 My other car is a boat

    Joined:
    Mar 2, 2006
    18,058
    3,032
    7
    Location:
    Northern Michigan
    Vehicle:
    2006 Prius
    Only empirical. It seems to vary by car. Obviously the bladder is more flexible in warm weather.

    Tom
     
  3. tkil

    tkil New Member

    Joined:
    Jan 26, 2006
    158
    2
    0
    Vehicle:
    Other Non-Hybrid
    While I don't have an equation for max fill at different temperatures, my experience with my 2005 shows that every degree Fahrenheit allows about 0.03 more US gallons per fill. (Not that there's any real reason to suspect that the effect is linear...) In your case, every 20°F increase should allow you to pump in an extra 0.6 USgal.
     

    Attached Files:

  4. donee

    donee New Member

    Joined:
    Aug 15, 2005
    2,956
    194
    0
    Location:
    Chicagoland
    Vehicle:
    2010 Prius
    Model:
    III
    Hi Jay,

    The change is most dramatic around freezing. My experience is that between 25 F and 50 F was a gallon. I filled up at 25 F just after the tank went from 3 to 2 pips, and then again at 50 F again just after the the change from 3 to 2. The car filled up exactly one gallon more, at the same pump.
     
  5. pt95148

    pt95148 New Member

    Joined:
    Dec 28, 2007
    39
    1
    0
    Location:
    SJ
    Vehicle:
    2008 Prius
    I just filled up at noon today when temp is 90+F in Northern California.
    I always filled up at 2 pips. The total gallon is 6.48.
    No difference to when temp was 70F.
    I wonder here?
     
  6. donee

    donee New Member

    Joined:
    Aug 15, 2005
    2,956
    194
    0
    Location:
    Chicagoland
    Vehicle:
    2010 Prius
    Model:
    III
    Hi PT...,

    Hmm. That seems an awful low amount. I would guestimate my car would fill up about 9 1/2 gallons at 90 F, just when the third pip goes off.

    You might have had a pump with a low trip pressure.
     
  7. JimboK

    JimboK One owner, low mileage

    Joined:
    May 1, 2006
    2,817
    179
    49
    Location:
    Chesterfield, VA
    Vehicle:
    2005 Prius
    It's not exactly scientific, but click either of the banners in my sig to see my fill-ups with their seasonal variations. I almost always wait until the last pip starts flashing, so that should provide a reasonably consistent reference point. For this purpose, ignore the tanks in mid-July last year; they were in the midst of a 2000 mile round-trip drive where I refilled at one or two non-flashing pips.
     
  8. dogfriend

    dogfriend Human - Animal Hybrid

    Joined:
    Feb 26, 2007
    7,512
    1,156
    0
    Location:
    Carmichael, CA
    Vehicle:
    2007 Prius
    In the tech training literature available here, they make this statement:

     
  9. ph43drus

    ph43drus Junior Member

    Joined:
    Jan 9, 2008
    44
    7
    0
    Location:
    Left of Center
    Vehicle:
    2012 Prius
    Model:
    Three
    This is a great plot, but I'm scratching my head about some of the points. Some of the higher temperature points seem a bit extreme - several are above the boiling point of water, waaaay above the initial boiling point of gasoline.
     
  10. tkil

    tkil New Member

    Joined:
    Jan 26, 2006
    158
    2
    0
    Vehicle:
    Other Non-Hybrid
    That's because I'm stupid. I thought I used Celsius, but of course those are in Fahrenheit. Ooops.

    I wasn't exactly at 100% the last two days, lots of travel and not much sleep. Thanks for double-checking! :)
     
Loading...