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87 octane regular vs 89 octane 10% ethanol

Discussion in 'Gen 2 Prius Fuel Economy' started by captain archer, Aug 24, 2006.

  1. captain archer

    captain archer New Member

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    had a question. here in iowa (well at least in des moines) the ethanol blend is actually at least 6 cents per gallon cheaper than the regular 87 octance. is there perhaps some way of calculate the cost tradeoff to see if it actual is better to pay the higher price for the regular gas?
     
  2. kDB

    kDB New Member

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    30% hit from ethanol, 10% ethanol so...
    multiply regular * 0.97 and that's should be about correct.
    for instance, at $2.759 for regular, unless ethanol is less than $2.67623, your probably better off with regular. though this does not count the emissions difference.

    someone correct me if i'm wrong.
     
  3. captain archer

    captain archer New Member

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    <div class='quotetop'>QUOTE(kDB @ Aug 24 2006, 09:09 AM) [snapback]308723[/snapback]</div>
    thanks kdb that helps a lot. so as prices go down here. like tonight entanol is at $2.519 and regular is $2.579 its almost worth the mpg hit to take the ethanol, but if prices go up the the spread between ethanol and regular stays the same it is worth paying more per gallon for the regular
     
  4. tmorrowus

    tmorrowus Member

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    I noticed that price difference when I was driving through Iowa. It was strange for the 89 octane gas (ethanol blend) to be cheaper than the 87. I went with the 87 since the Toyota owners manual seems to say these cars run best on 87.
     
  5. FL Buckeye

    FL Buckeye Member

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    We were driving through IA and NE this summer. The temp in NE was 107 one day. Anyway, I tried the 89 w/ethanol cause it was cheaper. My mpg on I80 went down from 48 to 43 in just a few miles. Surprisingly, in CO the reg was only 85 and the Prius ran like a champ on it, back up to the 48's. as they say, YMMV.
     
  6. eagle33199

    eagle33199 Platinum Member

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    just make sure the ethanol blend is just E10, and NOT E85.

    But like others said, you'll take a MPG hit when addind ethanol to the gas, since it doesn't contain as much energy. However, a little ethanol is apparently good for things, as it helps keep the engine and pipes, etc clean.
     
  7. troe

    troe New Member

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    <div class='quotetop'>QUOTE(tmorrowus @ Oct 19 2006, 06:50 PM) [snapback]335320[/snapback]</div>
    I moved to Panama City several years ago from Wyoming. Most people don't know that 87 octane is the same as 85 octane at high altitude.

    With the hit on E10, how can those trucks and SUV's afford to drive on E85? Just glad I traded my 15 MPG Jeep Wrangle for my Prius. My comute is a lot more enjoyable and I use 1/4 the gas to do it. B)
     
  8. john1701a

    john1701a Prius Guru

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    <div class='quotetop'>QUOTE(pcflorida @ Oct 20 2006, 08:02 AM) [snapback]335487[/snapback]</div>
    That's a somewhat redundant question, since you can ask the same to those owners about gas too.

    Nonetheless, a photo like this from Minnesota helps to provide that answer...

    [​IMG]
     
  9. captain archer

    captain archer New Member

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    john, correct me if im wrong, but isn't the gas up there in the frozen north all at least 10% ethanol? am taking a trip up there this winter to visit family up in the Aitkin and Brainerd areas, wondering what mpg to expect while up there. on a side note with it in the 40s here in des moines i have noticed a serious drop in my mpg from mid 50's to like around mid to upper 40s per gallon