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very wierd in regards to gas tank fullage

Discussion in 'Gen 2 Prius Fuel Economy' started by newlifein5, Apr 30, 2007.

  1. newlifein5

    newlifein5 New Member

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    I just came back from a trip (kentucky to chicago to kentucky)

    i remember i my gas meter was blipping at me at 389 miles of driving for that fill up. when i went to put gas i remember the reciept said 9.286 gallons full.

    so just the other day, i had to fill up my gas tank again. this time, i still had about 2 bars left. and it filled up at 9.175 gallons.

    THAT IS VERY WIERD. 9.286 - 9.175 = 0.111 gallons. TWO BARS on the gas meter does not equal .111 of a gallon.

    either gas meter reading wrong or gas station lieing to me. not sure but any1 notice something like this?

    u figure the gas meter on the prius has 10 bars right? if it holds about 9.2 - 9.5 imp gallons so that comes out to about .92 - .95 of a gallon per bar.

    not .1111 for two bars!!!!

    just something is not adding up. i have a 2007 base prius.
     
  2. Syclone

    Syclone Member

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    <div class='quotetop'>QUOTE(newlifein5 @ Apr 30 2007, 10:40 PM) [snapback]432984[/snapback]</div>
    Any idea of what the air temperature was during both fill-ups?
     
  3. newlifein5

    newlifein5 New Member

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    air temp was the same. i know when filling up in hot weather expands gas molecules and etc...,

    but even if air was different, it should not have made that much of a difference, 2 BARS?

    something just don't add up.
     
  4. bestmapman

    bestmapman 04, 07 ,08, 09, 10, 16, 21 Prime

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    <div class='quotetop'>QUOTE(newlifein5 @ Apr 30 2007, 10:40 PM) [snapback]432984[/snapback]</div>
    Where in Kentucky is Chi town?
     
  5. Highly ImPriused

    Highly ImPriused Impressive Member

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    What I think is happening is the gas gauge calibrates itself based on your fillups. So it should become more accurate over time. Mine was way off on the first tank (estimated less gas than was really there - which is better than the other way aroun), but has been more accurate since. Of course the differences could also have to do with the bladder contracting more or less under different conditions, but that doesn't sound like the case for you if temps were the same.
     
  6. HOGG0514

    HOGG0514 New Member

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    <div class='quotetop'>QUOTE(Highly ImPriused @ May 1 2007, 10:27 AM) [snapback]433237[/snapback]</div>

    actually all car makers are the same the fuel gauge at half is really down 2/3 this is done to give the impression that you are getting better fuel economy. The last half is real only 1/3 of the tank thats why you get approx 150 miles before it comes off full.
     
  7. acdii

    acdii Active Member

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    I wait until it beeps to add fuel, and I usually get about 10 gallons in.
     
  8. Charles Suitt

    Charles Suitt Senior Member

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    :rolleyes: It is an error to think the GUESS GAUGE is linear - as in assigning an amount of fuel to each blip. Such a concept could result in being out of fuel at an inconvenient time and place.

    I usually add fuel when I see the last UNBLINKING blip regardless of the miles traveled since the last fill. This way, I never run out of fuel.

    IT WORKS FOR ME.. :D
     
  9. avdavsim

    avdavsim New Member

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    <div class='quotetop'>QUOTE(Charles Suitt @ May 26 2007, 12:14 PM) [snapback]450447[/snapback]</div>
    Your telling me!

    I stay on 10 pips until well over 100 miles (about 125 maybe) but a few miles after I get down to 9, I go down to 8. I drove about 30 miles on the last pip blinking and still only got 10 gallons in (temp somewhere in the 80's). I'm finding I can trust the trip distance and cumulative MPG to calculate my fuel need much more accurately.
     
  10. pyccku

    pyccku Happy Prius Driver

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    I just filled up for the first time.

    We got a good 180 miles before the first pip went away. The next pip was only good for 30 miles.

    I noticed when it changed from 3 to 2 blips and kept track of the miles - I was at 62 miles and still had 2 blips left when I filled the tank, so I'm not exactly sure when it would have gone away.

    It took 10.047 gallons to fill, average of 48.07 mpg. Not bad for a first tank with 5 people in the car and the a/c running 80% of the time, I think. Certainly better than the 23 mpg we were getting in the Sienna.

    The best part was driving up to the pump as the SUV in front of me drove off. He had paid $74.70 to fill his tank. I paid $29.43 to fill mine, and will probably get more than double the miles he'll get out of that tank!
     
  11. diamondlarry

    diamondlarry EPA MPG #'s killer

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    <div class='quotetop'>QUOTE(pyccku @ May 26 2007, 03:30 PM) [snapback]450524[/snapback]</div>
    I had 248 miles and still had all of my pips on my first tank. I thought something may have been wrong so I went to top off. I was only able to squeeze 3.3 gallons in resulting in 75.1 mpg. I had previously topped the tank to the point of fuel being visible in the filler since I figured the dealer didn't really get it full.