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Strange fillup

Discussion in 'Gen 2 Prius Fuel Economy' started by Walker1, Feb 17, 2006.

  1. Walker1

    Walker1 Empire

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    I went to fill my "Gumdrop" last night. I always fill on the lowest automatic setting and then round up to the next dollar.

    However, this time the pump shut. When I went to round up to the next $ I could only put 20 cents more in. The tank was full.

    My manual milege equated to 43 MPG, computer said 52 MPG. I figure for whatever reason the pump filled the tank almost to the top. I have read that a Prius tank holds between 1 & 2 gallons after the first click shutoff.

    Has anyone else experienced this? All other factors were the same. Thanks. :(
     
  2. Betelgeuse

    Betelgeuse Active Member

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    The statement that the "Prius tank holds between 1 & 2 gallons after the first click shutoff" is incorrect. The amount of additional gas that you can "squeeze" into the tank varies widely, based on the pump, the air temperature, the speed at which you fill, the mood of Bill Merchant, etc.

    I've had times where I knew the tank could take more gas, but I couldn't make the pump put any more in. I've had times where I put in ~3 gallons after the click. Then, there was the time where I had the pump going on the "first pump" (i.e BEFORE the click-off) and, after I pulled the nozzle out, gas starting coming back OUT of the tank (I'd clearly overfilled it, but without any effort to top-off). It must have spit a cup or two of gas back onto the pavement. As someone else posted here, the Toyota web site points out that ONE CUP of spilled gas releases the same number of hydrocarbons into the atmosphere as you do in driving the Prius 8000 MILES.

    The short version of this story is that TOPPING OFF ISN'T WORTH IT. I understand the draw of doing it (i.e. trying to get a "great tank"), but we all live close enough to gas stations that we really don't need to worry about getting every last milliliter of gas into the tank.
     
  3. richard schumacher

    richard schumacher shortbus driver

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    Why?
     
  4. Walker1

    Walker1 Empire

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    For consistency & accurate milege. If I do the same fillup the same way each time I most always get an accurate MPG. I never try to overfill the tank.
     
  5. maggieddd

    maggieddd Senior Member

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    how does rounding up to the next dollar give you consistency & accurate milage?
     
  6. Walker1

    Walker1 Empire

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    It was something someone on this forum suggested to me. He is a senior member.
     
  7. maggieddd

    maggieddd Senior Member

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    is this a joke?
     
  8. ScottY

    ScottY New Member

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    If you always round up to the next dollar, ur calculation will always be incorrect. Let's say one time the pump stopped at $10.10. You keep filling up till $11. Next time the pump stopped at $10.99, you filled it up to $11. How do you keep an consistant measurement? This might explain why ur calculated MPG (43) is so different than the MFG read out (52).

    Just stop whenever the pump clicks.
     
  9. maggieddd

    maggieddd Senior Member

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    that's exactly what I asked.
    So I assumed this must be a joke
     
  10. Walker1

    Walker1 Empire

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    I guess I'll try that next time. Is that how you check your MPG?
     
  11. tomdeimos

    tomdeimos New Member

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    I never stop at clicks. I virtually always get 3 more gallons in after the click offs start.
    Crazy to stop for gas and only fill half the tank.
     
  12. gschoen

    gschoen Member

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    Using the same pump each time and filling slow might give more consistent results, the idea being the shut-off on the same pump would about the same and slow fill minimizes shut off due to pressure.
     
  13. Rancid13

    Rancid13 Cool Chick with a Black Prius

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    I've never topped off after the pump auto clicks off, with my previous car and with the Prius. I'd rather leave it be instead of trying to squeeze that last gallon or 2 or 3 in and risk spilling out gasoline on my car, the ground, and myself.
     
  14. ScottY

    ScottY New Member

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    I check my MPG by looking at the MFD. Many ppl reported that the calculated MPG is very close to the MFD read out.

    But some ppl like to keep track of their life time MPG. You can do whatever you like, but I'm just too lazy to do that kinda stuff. I am happy to know I get high 50's to low 60's in the summer, and mid 40's to low 50's in the winter. I don't need to know my life time MPG is 50.1958322.
     
  15. galaxee

    galaxee mostly benevolent

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    rounding up to the next dollar won't be consistent because the price per gallon always varies.

    i always have the urge to try to top it off but i resist unless it's like a 6 gallon fill. your manual numbers will even out long term, but will be off individually because of the bladder fluctuations.

    you can mess up your evap system by overfilling regularly, and like someone else pointed out the HC emissions are horrible when you spill gas.
     
  16. Catskillguy

    Catskillguy New Member

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    :lol:
     
  17. Walker1

    Walker1 Empire

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    You should have been around here last fall after Wilma came through. I have 15 5 gal. plastic jugs in the garage for the emergency generator. I most always fillup before any approaching storm. Well, I'm not trying to stuff the tank-just trying to see if computers are always accurate. One time I geo a manual reading of 30 MPG while the computer said 52.6 Can you explain why that happens?
     
  18. PASNGAS

    PASNGAS New Member

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    Hi~ I'm on my second tank of gas, now at half point. I traveled almost 900 miles. I'm averaging 40mpg but I do in live in the mountains of western maryland, 2000 ft above sea level. I'm assuming I won't get anything better!?!?

    Thanks for the info about 1 cup/8000 miles= hydrocarbons!!!!!!!!!! I will never fill more than the click of the finish sound!!!! WOW!!!!!!

    Would love any feedback! Thanks!
     
  19. earnyermoney

    earnyermoney New Member

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    I have been having problems with my 2005 Prius the past several months. I have seen the gas gauge indicate a tank three quarters empty. When my wife or my self try to refill the tank the pump cuts off way before it should. This past week, the tank indicated half empty, meaning I should be able to put 6 gallons in the tank. I could only put 3. Screen said we averaged 49 mpg. but manual indicated 70 mpg.

    At the next half tank empty I was able to put in 6 gallons with 180 miles. manual came out to 30 MPG while the screen was reading 50.1 MPG.


    I can understand a small discrepancy but the above is just piss poor. I'm tired of the dealership giving me the run around over this issue. I have a 91 Toyota Camry with 205,000 miles. Still going strong. If they keep giving me the run around I'll be calling the State Attorney General's office.
     
  20. paprius4030

    paprius4030 My first Prius

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    Rounding to the dollar although it may be a personal preference, doesn't have anything to do with mpg's. Since to compute it you use miles and gallons used, not dollars put into the tank.