Question about octane

Discussion in 'Lawn Mowing' started by white1, Jul 15, 2008.

  1. white1

    white1 LawnSite Member
    Posts: 108

    Worked in refineries for 12 years, been around hot rods for about 20 yrs. I understand the differences between 87 and 93 and what they allow in conventional 4 cycle engines.

    That being said, I remembered today while I was filling up my 2 stroke tank, that when I bought my shindiawas the red max poster said "89 octane, ask us why" I didnt, but now Im wondering, why?

    I run 93 in my go-devil with a 23 vanguard cause I was told its a high compression engine (my idea of high compression and Warren Coco's are different lol) and no more gas than it burns why now?

    My primary truck has a high compression bla bla. it NEEDS 93 octane, people ask why you use that expensive stuff. At the time there was a 10 cent difference between grades, so 20 cents difference from 87 to 93. Thats about $5 per tank, and the way the truck runs, it NEEDS 93.

    Whats the reason for running higher octane gas in these 2 strokes?
     
  2. Richard Martin

    Richard Martin LawnSite Fanatic
    Posts: 14,700

    They build them to run lean with "high" compression.
     
  3. dishboy

    dishboy LawnSite Platinum Member
    from zone 6
    Posts: 4,318

    I believe the oil in the mix also lowers the octane also, or so I have been told by a engine guy.
     
  4. green monster

    green monster LawnSite Member
    Posts: 148

    Whatever you do, don't run anything with more than 10% ethanol in your 2 stroke. The fuel (with a tiny bit of oil) is all that is lubricating that engine that can be running up to 10,000 to 12,000 rpm. Some gas stations sell the pure premium gas, which is the best.
     

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