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First tank stats and question

Discussion in 'Gen 2 Prius Fuel Economy' started by brian albert, Mar 27, 2005.

  1. brian albert

    brian albert New Member

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    When I picked up the Prius it had a full tank of gas and 8 miles on the odometer. I filled it up for the first time last week. Odometer read 325 miles, 2 bars left on gas meter, put in 5.73 gallons. The math says 56 miles per gallon, yet the on board computer gives me an average of about 42 to 43 mpg. Anyone else experience this or have any explanations ?

    Thanks,
    Brian
     
  2. jh90206

    jh90206 New Member

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    Congrats on the car and the great mpg no matter which is correct. I filled up the first time and put just under 7 gallons with the gage on 2 bars. The computer said mpg was low 40s and the math was 45. Sorry I don't remember the exact figures. When you filled yourself did you stop at the click or add as much as you could squeeze. If you let it quit at the click, I would guess the dealer gave you a full, full tank. I just filled up a second time and my calculation was again higher than the computer but only by approx 3 mpg. I think it will become more accurate when you do the next tank.

    Happy Driving,

    jh90206
     
  3. BobA

    BobA New Member

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    Brian.. I think the first tank of gas is like the first baby... it can come any time after the wedding.. after that it's nine months...

    All kidding aside..

    First, you don't know how or when the dealership filled your tank..

    When you fill it you will make the decision when to shut the pump off and probably will carry a book that you will make notes as to gallons, miles, date.. and what ever you think needs to be noted about your driving habits and go from there..

    You will know what you've done and how you've driven and what you real MPG is.

    Bob Andersen
     
  4. brian albert

    brian albert New Member

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    When I filled it I let it quit at the click and did not add more gas. What is the prefered method with the Prius. Are folks topping off ? If so, how much additional volume are they able to add ?

    Thanks,
    Brian
     
  5. jkash

    jkash Member

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  6. Ray Moore

    Ray Moore Active Member

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    In counterpoint to the three links, I always top off with at least an extra gallon. I figure I should be able to get in at least as much as the computer says I have used. Be careful though. As the links suggest, it is possible to overdo it and spill some. I get 600 to 700 miles from nearly every tank. My highest was 763 miles from 12.74 gallons. Not bad for an 11.9 gallon tank. Enjoy the ride.
     
  7. brian albert

    brian albert New Member

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    This second tank is weird. I have a 150 miles on the tank and only 4 bars left on the gas gauge. MFD says I am averaging 44.3 miles on this tank. Comments ?

    Thanks,
    Brian
     
  8. Tideland Prius

    Tideland Prius Moderator of the North
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    That is possible. Looking back at my chart, I did get a tank very similar to yours. It was December, my MFD read 5.2L/100kms (~45mpg) and pumped 18 litres (~4.76 gal). I had 313kms (196mi) on that tank. My guess is that I pumped at 4 or 5 bars.

    How's the weather there? could it be the colder temperatures?
     
  9. brian albert

    brian albert New Member

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    Typical Chicago spring weather. Three or four days of mid 30s to mid 40s then a couple of days in the 50s and 60s. Tempature oscillates quite a bit in March. Could it be that when it's cold that the fuel bladder does not expand as much and you cannot put as much fuel in the car. Maybe when it's cold instead if a 11.9 gallon tank you have a 9.9 gallon tank and the fuel guage adjusts to say that is a full tank. Just speculating here. Any ideas ?

    Thanks,
    Brian
     
  10. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    Brian welcome to the forum. i strongly suggest you keeping a chart of your mileage with data from both the computer and the pump.

    i think you will find that in the long run, all things will pretty much even out. the bladder makes it tough to get uniformity in the tank fillups.

    as far as topping off. i dont do it. i dont have the need to do it. i still get 500+ miles on a tank. i guess its possible that stuffing the tank might expand the bladder a bit, but i have no issues with the cars range. so its up to you. i will say that this is the only car i never topped off and i have spilled at least a little gas on every car i have owned except this one.
     
  11. QuickS2ilver

    QuickS2ilver New Member

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    I just filled my first tank! and here is my stats:
    -400 miles with the bar blinking for about 15 miles
    -computer 45.2 mpg
    -actual 42.2 mpg

    I hope to see some increases!!! I was a little disappointed but I keep hearing that the mpg's increase after break in.
     
  12. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    QuickS2ilver:

    in your case, use the computer numbers. your dealer filled your first tank and probably did not top off. (that is their policy) so you most likely are "fuller" than when you started resulting in the lower actual mileage reading. and yes as you get used to the car and how it drives, you will improve. also your anticipation will get better with practice