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Losing gas rapidly after first bar

Discussion in 'Gen 2 Prius Fuel Economy' started by fishys1, Jun 26, 2015.

  1. fishys1

    fishys1 Junior Member

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    i've noticed on my 2008 prius that once i lose the first bar of gas i begin to rapidly lose the rest. For example the first bar might take three days to vanish but once its gone i might lpse the second bar on the same day i lost the first. Is that normal? What can i do to prevent this?
     
  2. mmmodem

    mmmodem Senior Taste Tester

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    The fuel gauge on all cars do not display "actual" full and "actual" empty. It displays near full and and near empty. Imagine the fuel tank is 12 gallons. The fuel gauge will only display a range of 2 to 11 gallons. So 1 or 2 gallons displays 1 bar. 11 or 12 gallons display 10 full bars. The first bar is 2 gallons worth, all remaining bars is 1.

    Why it displays near empty instead of actual empty is obvious. You have a larger cushion so fewer idiots run out of fuel. Why near full instead of actual full. I don't know. I speculate so that fewer customers complain how that 10th bar lights up and thinks something is wrong with the car. But in actuality it's because the fuel pump keeps cutting out early. Also get a false sense of greater fuel economy. Look at that I've driven 100 miles and my tank is still full! After that first bar goes away I forget when the last time I filled up.
     
  3. Munpot42

    Munpot42 Senior Member

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    +1
     
  4. bisco

    bisco cookie crumbler

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    you have a bladder. in your tank. it makes the gauge do funny things some times. the only fix is trade up to gen III. welcome to priuschat!(y) are you new to the '08?
     
  5. Beachbummm

    Beachbummm Senior Member

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    mine goes about 140 miles before the first bar than 60 miles to the half way mark..i just fill up every 300 miles to be save
     
  6. RRxing

    RRxing Senior Member

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    Although the attached is for the Gen III, it helps to explain mmmodem's comment...
    PIPs_1024.jpg
     
  7. wjtracy

    wjtracy Senior Member

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    Gen2 the first pip can last over 150-miles normalized to 50 MPG.
    After that the next pips drop fairly fast each 20-30 miles, again adjusting to 50 MPG.
    I've uploaded my data peviously and will do so here when I get home.
    No way to stop it, that's just the way it works.
     
  8. fishys1

    fishys1 Junior Member

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    Yes I've only owned it for about a month now. Thank you :3
     
  9. bisco

    bisco cookie crumbler

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    you will get used to it, but you can't trust the 'guess o meter'. learn to use your average mpg divided into miles driven, or just fill up when there are at least 2 pips left.

    that's nothing though, wait until you try to pump gas, and it won't take any, you'll be back.:p
     
  10. Melchior

    Melchior Junior Member

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    Is the Prius your first car? I ask because I've seen the same behaviour on all cars I've ever owned so wonder if you've never seen this before.
     
  11. mmmodem

    mmmodem Senior Taste Tester

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    This type of questioning is common on PC. I attribute this to the wealth of digital information the Prius offers the driver. Previous vehicles did not display this information or showed it in analog.

    While arguably more precise, an analog fuel gauge does not indicate information as succinctly as a 10 bar digital gauge. You'll also see questions about the hybrid battery level being low. Or conversely, the battery level never gets full. Why does it have to be a problem either way? Why is fuel economy low after driving less than half a tank brand new off the dealer lot? Because you didn't calculate actual consumption by filling up the tank and you're reading the trip meters that have never been reset. And then there is the omnipresent speedometer shows faster speed than actual. Again, every single car, I have owned is like this. Even before GPS was ubiquitous, those LED signs displaying your speed always showed a slower speed than my car indicates.

    These are the same questions that will we asked on this forum over and over again as new drivers enter this digital driving world. It's a good thing.