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Ethanol (E10) and mileage?

Discussion in 'Gen 2 Prius Fuel Economy' started by larkinmj, Jun 15, 2006.

  1. larkinmj

    larkinmj New Member

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    Gas stations in Rhode Island went to 10% ethanol in late April. As I have only had my Prius for several months, and the changeover to E10 occurred as my car was getting broken it and the weather was getting warmer, I don't really have any data to ascertain the effect on mileage. I am curious if any long-term Prius owners noticed a change in mileage when switching to E10. My guess is that if it effects mileage at all, it would be barely perceptible.
     
    #1 larkinmj, Jun 15, 2006
  2. ScottY

    ScottY New Member

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    <div class='quotetop'>QUOTE(larkinmj @ Jun 15 2006, 10:04 AM) [snapback]271603[/snapback]</div>
    Well, my data is not scientific at all, but I'll give it a shot. Last summer, my mileage was around high 50’s to low 60’s. This summer, mileage is only around low to mid 50’s. But now I have the comfortreads, and last summer I had the OEM. The comfortreads should be broken in already. Had more than 15k miles on them. Again, this is not scientific at all, since other variables are introduced.
     
    #2 ScottY, Jun 15, 2006
  3. john1701a

    john1701a Prius Guru

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    Since E10 is all my two Prius have ever used (it's mandatory here in Minnesota), my data should satisfy your curiousity...

    Classic Prius average after 59,827 miles: 45.4 MPG

    HSD Prius average after 54,710 miles: 48.5 MPG
     
    #3 john1701a, Jun 15, 2006
  4. tomdeimos

    tomdeimos New Member

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    E10 has cut my mpg by about 3 mpg.
    About what it shoud do from the btu loss.
     
    #4 tomdeimos, Jun 15, 2006
  5. Skwyre7

    Skwyre7 What's the catch?

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    <div class='quotetop'>QUOTE(tomdeimos @ Jun 15 2006, 02:10 PM) [snapback]271723[/snapback]</div>
    Same here.
     
    #5 Skwyre7, Jun 15, 2006
  6. Tadashi

    Tadashi Member

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    I have not seen any change in my fuel economy. My tanks filled with E10 with at least 200 miles got me 56.1, 52.9, 65.6, 55.2, and 57.9 MPG. Afterwards without 55.4, 53.4, and this next tank will be around 65+ MPG.
     
    #6 Tadashi, Jun 15, 2006
  7. john1701a

    john1701a Prius Guru

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    <div class='quotetop'>QUOTE(tomdeimos @ Jun 15 2006, 01:10 PM) [snapback]271723[/snapback]</div>
    That is likely just a temporary effect, caused by the introduction of that new cleansing agent... a handy side-effect of ethanol.

    If there was really that much of a drop, those of us in Minnesota would have noticed the pattern years ago. Instead, it seems right in line with the 33% lower energy content. That translates to about 1.7 MPG.
     
    #7 john1701a, Jun 16, 2006
  8. larkinmj

    larkinmj New Member

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    <div class='quotetop'>QUOTE(john1701a @ Jun 16 2006, 08:56 AM) [snapback]272151[/snapback]</div>
    John,
    I'm assuming that you took the energy obtained from ethanol vs. gasoline (I don't have the figures in front of me and I know that a gallon of ethanol has less BTUs than a gallon of gas; didn't know that it was 33%), and then reduced the average mileage with gasoline by 3.3%? That makes sense. If so, and we can get enough anecdotal observations from drivers who have switched to E10 and average them, we should find about the same decrease in MPG.
     
    #8 larkinmj, Jun 16, 2006
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