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Prius C partial gas fill-up procedure

Discussion in 'Prius c Fuel Economy' started by Phil 29 Palms CA, Oct 17, 2013.

  1. Phil 29 Palms CA

    Phil 29 Palms CA Member

    Joined:
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    Location:
    Twentynine Palms, CA.
    Vehicle:
    2012 Prius c
    Model:
    Two
    For recorded keeping of my gas input I use fuelly.com. I link my fuelly.com membership to PriusChat so others can see how I perform MPG. I believe your MPG indicates your ability to drive the Prius C for maximum performance. Just an option... Here is how I manage a trip to the gas station. The Prius C gas gage has 10 lights (blue bars). When all ten bars are ON the fuel tank is full or almost full (9.6 gal.) I link my Trip A meter reading to control my gas input into the car. When I purchased my 2012 Prius C in August 2012 I decided to never change Trip B reading. Therefore, Trip B always indicates the total mileage of the car and average MPG for the total driving record. For every trip taken in the car, its performance during that trip is recorded on the ODM screen. I use the Trip A screen to control my fuel input into the car. This is how I do it. After fill-up all 10 bars of the full gage are ON. I drive my Prius C until I see the top 6 bars lights OFF and the 4 remaining lower bars are ON. At the exact time 6 bars are OFF and 4 bars ON, I read the Trip A screen and record the total miles indicated. This is the total miles driven since my last partial fill-up. After recording this mileage and saving it for entry into the fuelly.com fill-up data base, I press TWICE and HOLD the Trip A button on the steering wheel to reset Trip A to zero. It is important to do this as soon as the 4 and 6 bar configuration exists in the car. By doing this you will have the exact mileage and MPG data base reset in the car for the next fill-up time. You now have establish your total miles driven between fill-ups and MPG. At the gas station I read the exact price per gal. at the pump. I use my pocket calculator stored in the arm rest compartment to calculate the exact cost to pay the owner of the station for EXACTLY 5 gallons of gas. Example, 3.699 x 5 gal. = $18.495. I pay the station $18.50. By doing this I know the TANK WILL NOT OVER FLOW AND THE PUMP WILL AUTOMATICALLY SHUT OFF AT 5 GAL. I exactly put into the Prius C 5 Gal. of gas between fill-ups. When I leave the station all 10 lights on the fuel gage will be ON. I know when the ODM meter approaches 300 miles to monitor the Trip A meter for reset at the next 4 ON 6 Off light ratio. For me the 4 to 6 light ratio works. I am retired, drive little and only buy 5 gallons of gas about every TWO months. If you commute and drive a lot you can change the light ratio to 3 to 7 or 2 to 8. I would not try a 1 to 9 ratio unless you like running out of gas!!!
     
    #1 Phil 29 Palms CA, Oct 17, 2013
  2. Phil 29 Palms CA

    Phil 29 Palms CA Member

    Joined:
    Oct 19, 2012
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    Location:
    Twentynine Palms, CA.
    Vehicle:
    2012 Prius c
    Model:
    Two
    The sentence: "I know when the ODM meter approaches 300 miles to monitor the Trip A meter for reset at the next 4 ON 6 Off light ratio." is incorrect. It should read: "When the Trip A screen approaches 300 miles to monitor the fuel gage for the 4 light ON and 6 light OFF indication."
     
    #2 Phil 29 Palms CA, Oct 17, 2013
  3. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
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    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    What I do to calculated mpg:

    1. Use the Odometer readings, ie: the total kilometers driven since the car rolled out of the factory. This never gets reset, and when the reading is recorded at a gas fill up, and the previous fill up recording subtracted, you have the fillup to fillup distance travelled. I do reset Trip A at each fillup, but that's just as a check, for feedback as I drive. I don't count on it. It's too easy to accidentaly reset.

    2. I fill up whenever it's convenient/sensible, ie: anytime the tank is getting lowish, and I'm going by my favourite brand. I put in gas 'till the auto-shutoff kicks in, and stop. Anytime it's below half full is fair game.

    3. If there were to be a partial fill, say due to someone borrowing the car, putting in gas, no panic: as long as I know how many liters went in. I'll retain that value, and combine it with the next (full) fillup, do the calculation spanning both fillups.
     
    #3 Mendel Leisk, Oct 17, 2013
  4. Mr Incredible

    Mr Incredible Chance favors the prepared mind.

    Joined:
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    Location:
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    Vehicle:
    2012 Prius c
    Model:
    Four
    I use Trip A as my tank meter. Reset Trip A, fill up. Drive until you need to get gas again. Divide the miles on Trip A by the gallons of the fill up. Reset Trip A.

    Repeat as required.
     
    #4 Mr Incredible, Oct 23, 2013
    Stevie and ztanos like this.
  5. ztanos

    ztanos All-around Geek!

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    Location:
    Cumming, Georgia
    Vehicle:
    2012 Prius c
    Model:
    Four
    Use fuelly or other app as required... no maths necessary. :)
     
    #5 ztanos, Oct 23, 2013
  6. Mr Incredible

    Mr Incredible Chance favors the prepared mind.

    Joined:
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    Four
    Maths can be had, like, instantly.

    Fuelly requires getting back to base, logging in, typing, hitting buttons. Way too intense.
     
    #6 Mr Incredible, Oct 23, 2013
  7. Stevie

    Stevie Junior Member

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    Location:
    Melbourne,Victoria,Australia
    Vehicle:
    2012 Prius c
    Model:
    N/A
    same as others above, I reset trip A when ever refiling, obviously then what ever is added divided by distance travelled = consumption, but also like the first post I never reset trip B so have an overall average (currently 3.9l/100klm - 60mpg) after 7300klms
     
    #7 Stevie, Oct 23, 2013
  8. Tony D

    Tony D Active Member

    Joined:
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    Location:
    Dublin, Ireland
    Vehicle:
    2008 Prius
    Model:
    N/A
    That is exactly how I do and have used this method for years no matter what car I have driven.

    I usually drive until the orange light etc comes on and then fill up to the first click on the petrol pump or up to the nearesr round or 0.5 of a litre. On my last car, a Mk5 Golf FSI I'd usually run it to Okm on the clock and then fill. On our VTEC CR-V as soon as the needle drops and the light comes on I make it to the nearest petrol station for a fill.

    I use Fuelly to record the figures, but it's simply: distance travelled (I record both total and trip too for my own records) x the number of litres to fill
     
    #8 Tony D, Oct 24, 2013
  9. ztanos

    ztanos All-around Geek!

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    Cumming, Georgia
    Vehicle:
    2012 Prius c
    Model:
    Four
    Get out of the stone age brother. :) Smartphone app is one click.
     
    #9 ztanos, Oct 24, 2013
    Tony D likes this.
  10. Phil 29 Palms CA

    Phil 29 Palms CA Member

    Joined:
    Oct 19, 2012
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    Location:
    Twentynine Palms, CA.
    Vehicle:
    2012 Prius c
    Model:
    Two
    I do not have a need or use for a Smartphone. I do not spend hundreds of dollars a year for a subscription for a Smartphone! I paid $1.86 for my pocket calculator. I ask you, "Who is in the Stone Age." GET SMART!
    .
     
    #10 Phil 29 Palms CA, Nov 2, 2013
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