91 versus 93 octane

Discussion in 'Engine, Fuel and Exhaust' started by hogcowboy, Aug 29, 2012.

  1. hogcowboy

    hogcowboy Active Member

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    Will 93 octane make an engine run hotter versus 91 octane?
     
  2. hogcowboy

    hogcowboy Active Member

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    Thanks for the info Tank. Problem for me is the stations here only have 87 or 93 and I was concerned that maybe the steady diet of 93 might be causing it to run hot.
     
  3. markfsanderson

    markfsanderson Active Member

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    As strange as it sounds, I believe that running a higher octane gasoline is actually a bit cooler (assuming the same qty of gasoline vaporized). The amount of physical energy released is more, the amount of heat energy less . . . AFAIK . .that is!

    Mark - Thanks!:newsmile026:
     
  4. markfsanderson

    markfsanderson Active Member

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    Longer, slower and cooler . . . but it contains the same amount of energy - weird huh?
    Here's an interesting site: Does higher octane gas burn hotter or cooler then lower octane gas? | ChaCha
    and Does 93 octane gas burn hotter than lower octane gas? [Archive] - Classic Cougar Forums - cool stuff - literally!
    Although slightly off topic, diesel engines create more mechanical energy from the same amount of fuel than does gasoline - therefore it runs 'cooler' . . . How can diesels run cooler than gas? - TDIClub Forums gasoline releases more 'heat' energy . . . I always wondered why diesel engines have smaller radiators for the same output . . . or so it seems . . .
    Mark - Thanks!
     
  5. hogcowboy

    hogcowboy Active Member

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    Interesting. Thanks. I'm just trying to figure out why my 07 EGU would now be showing signs of a lean tune after all these years. Just doesn't make sense. Don't want to through money at it if not necessary.
     
    1 person likes this.
  6. Bodeen

    Bodeen Well-Known Member Staff Member Moderator Contributor

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    Ethanol may cause some of this or you could be developing a vacuum leak in the intake.
     
  7. BUBBIE

    BUBBIE Well-Known Member

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    Gasoline.

    ..High Octane = slower burning under pressure
    Lower Octane = Faster burning under pressure

    Low octane fuel has More BTU's than the High Octane.

    signed....BUBBIE

    added: Most motors will run a little Cooler using the Higher Octane. Slower burning/more octane = less heat (less BTU's)
     
  8. Jack Klarich

    Jack Klarich Expert Member

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    If you can find some alcohol free 89 octane try it, my bike runs good on it with NO knock:s
     
  9. hogcowboy

    hogcowboy Active Member

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    Unfortunately it's either 87 or 93 in this area.
     
  10. Jack Klarich

    Jack Klarich Expert Member

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