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Conclusions of 104 identical runs. Evolution of Fuel economy

Discussion in 'Gen 3 Prius Fuel Economy' started by FrankTiger, Dec 10, 2010.

  1. FrankTiger

    FrankTiger Member

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    Vehicle:
    2010 Prius
    Model:
    V
    Hi Everyone

    I am collecting OBD data from my Prius using an ELM327 Bluetooth connected to a Pocket PC (HTC HD) running OBDGauge freeware.

    My Prius is a 2010 European version loaded with every available option but LKA, which is not available in my country.

    I have recorded 104 identical runs starting and ending at the same parking places and following identical tracks, so I can prepare some graphics and reach some conclusions. The runs are 10.0 miles (16.2Km) with the ending point 90 feet (28m) below starting point. 62% is highway and 38% is city.

    In this first post I will show you a graphic of the Prius Fuel Economy versus Date. My Prius was delivered in February so the first months will be affected by the breaking-in. During the summer in Spain you can see that the fuel economy improves and when the temperatures go down in october, the fuel economy drops. The best fuel economy was at mid-september with an average of 67mpg

    [​IMG]

    In metric units, the graphic is:
    [​IMG]

    I must tell that the speed readings are internal Prius speed, that in my european specs Prius is about 5 miles lower than the speed shown in the dashboard. The fuel economy of the graphic is similar to the fuel economy shown in the dashboard, which is 7% higher than the actual fuel economy measured at the fuel pump.

    Big hugs from Frank
     
    #1 FrankTiger, Dec 10, 2010
    1 person likes this.
  2. don_chuwish

    don_chuwish Well Seasoned Member

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    Very cool data to have, it'll be interesting over time how the plot changes with driving skill, different tires, mileage on the vehicle, etc.

    - D
     
    #2 don_chuwish, Dec 10, 2010
  3. mite66

    mite66 Junior Member

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    Wow, nice work Frank :rockon:

    Unless your commute is affected by traffic density, I guess we may conclude that the ambiant temperature is definitely affecting the fuel consumption. You haven't recorded the air temperature on the days you were collecting data by any chance ?

    Otherwise, it would be cool to add another curve to your graph showing the average daytime temperature per month in your region.
     
    #3 mite66, Dec 10, 2010
  4. fotomoto

    fotomoto Senior Member

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    Hello Frank,

    How do you determine fuel pump accuracy? ;)
     
    #4 fotomoto, Dec 10, 2010
  5. FrankTiger

    FrankTiger Member

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    Hi fotomo

    Probably I did not use the correct words. I said "fuel pump" but I mean "the gas station fuel pump" , not "the car fuel pump"

    When I fill the tank I reset TRIP B; I compute the Prius expected gas volume (miles over mpg ; or in metric km/100 times l/100) and compare with the actual gas volume supplied by the gas station. In my car there is a 7% average difference between the two values. That is what I meant.

    Hugs from Framk
     
    #5 FrankTiger, Dec 10, 2010
  6. FrankTiger

    FrankTiger Member

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    Location:
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    2010 Prius
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    V
    Hi mite66

    Yes! I will post the graphics of fuel economy vs minimum air intake temperature (which is close to ambient temperature) but probably you will be surprised because it is very flat. The important temperature for fuel economy is the coolant initial temperature. You'll see that in the thread.

    Hugs from Frank
     
    #6 FrankTiger, Dec 10, 2010
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