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Fuel Gauge

Discussion in 'Gen 2 Prius Fuel Economy' started by NJDave, Jan 26, 2006.

  1. NJDave

    NJDave New Member

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    OK, another question from a new owner.

    The fuel gauge seems inconsistent. I notice that sometimes I lose a bar after 30 miles, other times after 47 miles. I am averaging 42 MPG right now, so I am not sure what each bar represents, mileage-wise.

    Bueller?

    :huh:
     
  2. galaxee

    galaxee mostly benevolent

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    yep, it starts out slowly at first and then drops more and more quickly.

    in the summertime when i can get more gas in the bladder, i can go 130+ miles on the first bar alone. just a quirk of the car. rule #1 is: when the car says gas, get gas! :)
     
  3. aaf709

    aaf709 Ravenpaw of ThunderClan

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    Some call it a "guess" gauge. :)

    I don't think you can say a bar is X number of miles. Generally I've found that the first goes at about 125 miles and I've gone about 200 miles at the 1/2 point. After the 1/2 point it seems to drop quickly.
     
  4. tumbleweed

    tumbleweed Senior Member

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    I use the fuel gage to give me a rough idea of how much I have. I tried to compute gallons per bar when I first got my car and soon gave up on the idea. In defense of the designers I think that it must be very difficult to design an affordable fuel gage that will work accurately with the bladder.

    When I get down to one or two bars left I head for a gas station because I hate to run out of gas. I do not wait for the last bar to start blinking.
     
  5. pgorbas

    pgorbas New Member

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    ACtually I have had several diffrent Toyotas, and they all have the 'fule gague flaw' (where 1/2 the tank gets reports as the top 1/4) - it seams that toyota egineres don't bother to use proper math to figure the quanitiy of gas in the tank or bladder. There are several solutions theoreticly availble to give an constant exact fule gale readout ( weight come to mind or with the bladder they could use a pressure sensor ) but that would raise the cost of the car production another 40 or 50 cents a car.... ;)
     
  6. Jack 06

    Jack 06 New Member

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    Driving home 245 mi. from the dealer yesterday, my first bar blipped off at 140, my second 100 mi. later. Two bars-240 mi. Averaging 50 MPG. It should drop like a rock soon.

    Welcome to the guess gauge.
     
  7. Vincent

    Vincent Don't Wait Until Tomorrow

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    Here's Your Fuel Gauge Answer

    The Prius Guess Gauge is very consistent. Here are the results of my calculations and observations after driving an 05 and 06 Prius for a combined total of 5 months:

    10 Dashes - Full, or almost full
    9 Dashes - Somewhere between 6 to 10 gallons remaining
    8 Dashes - Somewhere between 6 to 10 gallons remaining
    7 Dashes - Somewhere between 6 to 10 gallons remaining
    6 Dashes - Somewhere between 6 to 10 gallons remaining
    5 Dashes - Somewhere between 5 to 1 gallons remaining
    4 Dashes - Somewhere between 5 to 1 gallons remaining
    3 Dashes - Somewhere between 5 to 1 gallons remaining
    2 Dashes - Somewhere between 5 to 1 gallons remaining
    1 Dashes - Somewhere between 5 to 1 gallons remaining
    1 Dash Flashing - Time to get ot a gas station FAST

    Of course, if you want to display the real answer all the time, just reset your trip odometers at every fill-up.
     
  8. nbarnes81

    nbarnes81 New Member

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    :lol:

    I guess that would explain why the prius doesn't try to guess how many miles to go before next fill up.
     
  9. NJDave

    NJDave New Member

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    The car is down to 6 bars, and I have only gone 130 miles on this tank. yet, I am averaging 42 mpg.
     
  10. bluejay

    bluejay New Member

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    Hey NJDave,

    I'm in philadelphia--have the same dilemma. I can't figure how much gas I have by fill-ups either. I'm averaging 46mpg on 170 miles, this last tank, with 5 bars left. My first bar went at 57mpg, second 44mpg, then 32 mpg, then I stopped checking. Someone advised me not to use the fuel gauge for mpg calculations so I'm just waiting to see how far this tank will take me.
     
  11. Bassphil

    Bassphil Junior Member

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    Actually, about the flashing fuel gage. I just got my Prius last week, so I thought I push the limits of the fuel tank to see how far I could go.

    When the last bar started flashing, I drove another 10 miles then hit gas station, where I only pumped 2 gallons. (I wanted to make it the rest of the way home to where gas is cheaper).

    Anyway, after pumping two gallons, the last bar was still flashing. I drove another 13 miles or so to my neighborhood and filled up. I was planning on pumping 9 gallons or so in the tank, but 7 gallons topped me off.

    Soo, when the light started to flash, I'm assuming that I still had almost three gallons in the tank. At 47mpg, I was in no need of rushing to a gas station.

    Is there another light that pops on the dash after the last bar of the gas gage blinks for a little while? I wish the manual was a little more descriptive with their fuel warning lights...

    -P
     
  12. KTPhil

    KTPhil Active Member

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    I read here something along these lines: To avoid a jumpy gauge as you bounce the car. corner, or brake, the gauge will not change until you have added a minimum amount of gas. I think the amount is about 3 gallons, so your 2-gallon sip didn't reset the gauge.