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Full tank = 400 miles @ 50MPG Why?? :(

Discussion in 'Gen 2 Prius Fuel Economy' started by Gilbert, Mar 11, 2009.

  1. Gilbert

    Gilbert Member

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    Filled it up Saturday night, now today i had to refuel again after just 400 miles.. which has never happend before. I usually get atleast 450 miles on my tanks. I was surprised how quick the bars went down.. I had 2 left today, 10 miles to my home went down to 1, and 3 miles to my next destination it started flashing.. Ive never seen the first bubble go to blinking so fast before. Since its kinda cold here still, my mpg has gone down from the usuall 54-57 to 50.. My last tank as 49MPG(i was careless) and i refueled blinking bar with like 470 miles on it. So how come this one is 50MPG but less millage? :(

    Btw, also when im refueling, it typically clicks off at only 8-9 gallons with flashing bub.

    I have a 2008 pkg5. Everything stock, tire pressure should be stock as well, since i was at dealer about 3 weeks ago.
     
  2. Neicy

    Neicy Member

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    Simple answer is the fuel bladder. It is stiffer in winter, and in new cars. Plus gas pumps don't always click off at the same point every time. This has been one of the issues that lots of people have a complaint about. Also why people run out of gas. They expect the tank to hold 11.9 gallons. It NEVER will. I have never gotten more than 9 gallons into my car - even in the summer. When I fill at 2 PIPS it usually takes between 7.5 and 8 gallons. The good news is the Gen III does NOT have a bladder. They finally heard the message loud and clear.
     
  3. a priori

    a priori Canonus Curiosus

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    Just as Neicy says!

    Do not have the expectation that every fill-up results in 11+ gallons or gas in your tank. The one thing to rely on is the flashing pip. When you see it, then FLY to the next gas station.
     
  4. KK6PD

    KK6PD _ . _ . / _ _ . _

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    Instead of stock tire pressure, I would bump it up to 42 front 40 rear. A little stiffer ride, better MPG! Also don't forget temp, etc affect the filling process.
    Your results are typical for me. I get 400 for 8, but then I have a hill to drive up "2" everynight here in L.A. Without that hill, I would be doing better, but I am not complaining. Think what my 4Runner was getting on the same drive. I am definatly coming out ahead!!!
     
  5. EZW1

    EZW1 Active Member

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    Tip: If every fillup from the flashing pip result in 8 gallons or less then you might need to recalibrate the gauge. The readout on the dash is 'biased' by input from the az and el sensors. I'll provide the procedure upon request.
     
  6. Celtic Blue

    Celtic Blue New Member

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    Getting 9 gallons into the tank on a flashing pip is near cause for celebration in our '08 (managed it once so far.) It's not like the other cars I've owned where I could still see fuel level displayed and moving well below E (actually, the bottom 1/8th is usually below E, and the top 1/8th above F.) In them I could run to within 0.1-0.2 gallons of rated capacity, and have never run out of gas in them.

    The combination of bladder/vent system and a fuel gauge that will not display the lower 1/8th of the tank or so really handicap the useful range of this car.
     
  7. jenny_adams

    jenny_adams New Member

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    This has been useful for me as well, thanks!
     
  8. zenMachine

    zenMachine Just another Onionhead

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    Yes, please. Thank you!
     
  9. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
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    Gilbert,
    If you can find your last receipt, please let us know how many gallons you pumped in. This will give us an indication of bladder stetchiness. It will also most likely provide the math to show that (gallons * mileage) = distance.
     
  10. jtmhog

    jtmhog Member

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    I love my bladder!!! No problem with the variable capacity gas tank. Toyota has to deal with the gas vapors inside the tank--they have to minimize gas vapors to the world. The gen 3 will have some other system that may be troublesome. Long live the bladder!!
     
  11. EZW1

    EZW1 Active Member

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    Here 'ya go, jtmhog. Make sure the car is level before you start. This will reset the sensors and hopefully give you more accuracy on the fuel gauge:

    A. Start car in Ready Mode
    B. Go to "Trip A"
    C. Power down
    D. Make sure your foot is off of the
    brake pedal.
    E. Push in and hold the
    “ODO/TRIP” button.
    F. Turn the power switch ON
    (push the “POWER” button twice).
    G. Turn the “ODO/TRIP” button OFF,
    then ON 3 times within 5 seconds.
    H. Continue to hold the “ODO/TRIP”
    button until the “ODO” indicator in
    the display turns off and a 6–digit
    code (######) is displayed.
    I. Release the“ODO/TRIP” button.
    J. Push and hold the “ODO/TRIP”
    button for 5 seconds or more
    again. The 6–digit code (######)
    will then change to a 5–digit
    code (#####).
    K. After “1” is displayed at the 3rd
    digit of the 5–digit code, release
    the “ODO/TRIP” button.
    L. Approximately 5 seconds after “1”
    is displayed at the 3rd digit, the
    “TRIP A” indicators are displayed,
    and the odometer returns to the
    normal operation.[/i]

    NOTE:
    �� The “TRIP A” mileage will revert to
    0.0 miles in this procedure.
    �� Do not drive the vehicle before the
    reset procedure has been completed.
    HINT:
    If a write error occurs, start the
    procedure again from the beginning.

    the 5 digits you see will be

    X = first two digits
    Y = middle digit
    Z = last

    X: Values Written Into Meter
    (Longitudinal Direction)
    Y: Write Status and Result
    Z: Values Written Into Meter
    (Lateral Direction)
    Write Status and Result:
    0: Writing
    1: Write Completetd
    2: Write Error
    3: Write Canceled

     
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  12. zenMachine

    zenMachine Just another Onionhead

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    Not sure I understand step G and how it transitions to H.

    What do you mean by "Turn the ODO/TRIP button OFF"? I thought if you press that button it cycles to Trip A then Trip B the back to ODO again.

    Secondly, before step H, are you supposed to hold down the ODO button after the third time you "turn the ODO button ON"?
     
  13. richard schumacher

    richard schumacher shortbus driver

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    You are pressing ODO/TRIP as you enter step G. Step G can be re-written as:
    release-press release-press release-press, all within 5 seconds
    so that you are again pressing the ODO/TRIP button as you enter step H.

    I just did this. I'll report whether it makes any difference to my hitherto-8-gal-max fillups.
     
  14. PhillyChile

    PhillyChile New Member

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    I have always been disappointed with my range... Even after 100K
     
  15. xsmatt81

    xsmatt81 non-AARP Member

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    thank god they are getting rid of the bladder. The mileage and numbers people will get with 2010 are going to rock.

    I have driven it dry, to the point where warning lights lit up the dash like an xmas tree. Oddly I was stil able to drive with the ICE for a few miles till I found a service station, I was able to get a hair over 10 gal in..this was the only time ever.. Not pushing my luck again. I usually fill up at the last pip now
     
  16. ETP

    ETP 2021 Prime(Limit),24 Venza Limit,B52-D,G,F,H

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    Nice thread, I just did my first fill up which was 3.8 gal at the half tank mark and 274 miles driven (74MPG). My MPG gauge says 49MPG.

    So is the MPG gauge the most accurate check of MPG? I will continue to fill up at the half tank mark and see what happens. The dealer may have topped off the first tank which I never do.
    yep, need to put 2 psi extra in the front. Boy those 16" low profile ride rough at those pressures.
     
  17. JimboK

    JimboK One owner, low mileage

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    It is accurate enough for most folks. More accurate is to track cumulative MPG over many tanks based on actual mileage driven and fuel consumed, but that is obviously more cumbersome. The anal retentive among us (;)) have tracked the differences over an extended period and find the display to be about 2-3% on the high side.
     
  18. qbee42

    qbee42 My other car is a boat

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    Also remember that manual calculations are still vulnerable to the same odometer errors, plus any error from gas station filling pumps. You are never going to get MPG right on the money unless you install laboratory grade instrumentation.

    As JimboK points out, long term manual calculation has shown the MFD to be pretty accurate, and almost always slightly optimistic. For the short haul, the MFD is going to be your best bet.

    Tom
     
  19. ETP

    ETP 2021 Prime(Limit),24 Venza Limit,B52-D,G,F,H

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    Checked it twice since my post and it looks like 52 to 53 is pretty close for my commute to work and back. Adjusted the air pressure to 42PSI in the front to see how that does. I am reluctant to go to 44 or 46PSI as the low profile tires are stiff.
    I also bought my 5w30 synthetic for my first oil change at 3K.
     
  20. KK6PD

    KK6PD _ . _ . / _ _ . _

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    Hey, just wanted to say thanks for the tip.

    Where ever did you find this little info gem????

    When I put my 8 gal in it's right after pip 3 goes away...