Thread: Fuel

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  1. #1
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    Fuel

    Anybody out there noticed anyspeed or power difference between 91 octane and 93 octane 115 Merc 4 stroke

  2. Member
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    Oct 2013
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    Cleveland, TN
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    #2
    Do the Mercury 4 Strokes require 91 octane? I know my Evinrude calls for 87, but I buy 100% gas anyway so it’s always a little higher.
    white Vexus AVX 1980 - white Evinrude G2 150hp HO

  3. Member
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    #3
    I do believe so I'd have to read manual seems like I've lost about 2 mph since first tank of fuel and proper break in doesn't seem to matter if it's 1/2 tank or full tank same speed running about 47 to 48 GPS and also rpms are lower about 5900 to 6000 it was 6200 at 49 to 50 mph on gps just curious

  4. Member
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    Dec 2012
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    #4
    My 2015 Mercury 115 4stroke calls for a minimum 87 octane fuel. If you run higher octane than needed you’re really not going to gain anything and it can cause excessive carbon buildup. There’s lots of information about fuel and additives on the Mercury motor forums.

  5. Member
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    #5
    Ok thanks