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About Mpg and pips

Discussion in 'Gen 2 Prius Fuel Economy' started by tf4624, Feb 20, 2010.

  1. tf4624

    tf4624 Active Member

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    Ok I might ahve an issue or not

    How many miles should i have by the first pip dissapearing?

    Normly all pips to blinking i get 420-500 and that is a tank..10 gallons

    So mathamaticly 10 pips

    42-50 PER PIP..

    some one I have gotton 156 Mils from 1 pip so far from a full thank.. Not modded except Wheel skirts...

    I went from ATL to Tuscollusca ..220 miles total

    1 way there I used about 1/2 tank cOMP SAYS 47MPG avg

    The way back I used 2 pips cause I got 156 from the first PIP (comp also says 47mpg avg)

    I have not filled up yet to do the math on mpg but it should be Way above 50

    I'm lost or not? any comment might help
     
  2. Bob64

    Bob64 Sapphire of the Blue Sky

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    your gas tank is non-linear. You have less near the bottom and more gas near the top.
     
  3. CharleneN

    CharleneN Junior Member

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    Sounds like it got stuck for some reason :(
     
  4. BAllanJ

    BAllanJ Active Member

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    I've been thinking of doing some data collection on this.... writing down the "km since fillup" each time I notice another pip disappear... so 9 data points per tank, then average each over several sets. Eventually I could get a nice calibration curve. YMMV, so it wouldn't directly translate across different drivers or even the same driver at different temperatures, but may be interesting anyway... maybe when I'm doing a bunch of vacation driving this summer...
     
  5. tf4624

    tf4624 Active Member

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    Near top? i do all highway to work to and only get about 60-75 off first pip and not some crazy number like i stated
     
  6. JimN

    JimN Let the games begin!

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    Don't pay much attention to the "Guess Gauge". Start believing it at 2 pips.
     
  7. JimboK

    JimboK One owner, low mileage

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    I agree that it's normal non-linear behavior. (Most fuel gauges are non-linear.) The fuel bladder's behavior in various temperatures and how full you really get the tank on fillup are factors. I've gone anywhere from 50 (in winter) to 300 (in summer when I've squeezed in more fuel than usual) miles on the first pip, with the subsequent ones always taking less time to go.

    Charlene, it is not stuck.

    BAllanJ, I've thought of doing the same thing. It would make for an interesting study. Maybe on next fillup ....
     
  8. namasteflc

    namasteflc New Member

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    How many miles to go after the last pip starts blinking? I put on 24 miles after the blink, and still only needed 9.8 gallons to fill in my 2010.
     
  9. tf4624

    tf4624 Active Member

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    Ive gone consistant 50+ on blinking pip..so i account that as a gallon LOL but at that point its not PULSE AND glide.. If i did that be a lot more
     
  10. JimboK

    JimboK One owner, low mileage

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    Don't count on going 50 every time. You may only get five the next time. The bladder makes it quite unpredictable. Best is to add fuel ASAP when the last pip starts flashing, if not before.
     
  11. richard schumacher

    richard schumacher shortbus driver

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    Bladder or not, driving conditions affect MPGs (duh) so how far you can go on the last pip will be different each time. Assume a fixed figure and you may run out. Oopsie.
     
  12. sakai

    sakai New Member

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    I'll add my two cents worth of confirmation. I drive an 05 and it's 95% highway commuting. After a fill-up, I'll usually see 90-110 miles before the first pip goes away, and then it rapidly changes down to what seems like 40-50 miles per pip. One question that I have would be this - when people are filling up at a flashing pip, how many gallons are they able to add to the bladder? I've only once broken nine gallons (and 9.021 at that), which was probably only because I drove for 10 miles on the flashing pip because I really, REALLY wanted my first 500 mile tank. Mostly, I average low to mid 8's.
     
  13. Bob64

    Bob64 Sapphire of the Blue Sky

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    Around 8 gallons is what I normally put in.
     
  14. ksstathead

    ksstathead Active Member

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    On your gen3, you do NOT have a bladder tank, so you should have 'normal' cushion (have read up to 2 gals). Should be good for 50 miles or so after the last pip flashes, likely more. I fill up pretty quick when my last pip flashes, because I have no reason not to.

    Gen2 drivers: fill up earlier because your guess gauge is less predictable. Many threads on this issue.
     
  15. Bill1

    Bill1 New Member

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    Being an engineer (nerd alert) I did this for 5 tanks not long after I got my 09. There was plenty of variation in the values, but here are the averages I calculated for each pip:
    pip mi
    1 105
    2 38
    3 33
    4 39
    5 37
    6 44
    7 47
    8 49
    9 51

    I did not do the 10th pip, since I typically fill up soon after I get to it.
     
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