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Anyone run ethanol-free fuel? Or is premium best?

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  • Anyone run ethanol-free fuel? Or is premium best?

    Title says it all. Some gas stations around here have ethanol free fuel. Comes out of a red pump handle. I used it exclusively in my 911T without issue.

    Im getting ready to first start my freshly built Korman S14 with their Evo Power package. Would prefer to avoid the negatives of ethanol if ethanol free will work well. Particularly since this car will be an occasional driver and ethanol sitting in the fuel system isn’t great.

    thoughts welcome

  • #2
    depends on the octane rating of the corn-free gas....and what recommended octane for the new engine.
    75 M2
    88 M3


    • #3
      Have you run this past the engine builders at Korman? Seems they would have a good perspective on this subject.

      Ethanol fuel on its own is not necessarily a bad thing. Problems develop when you let Ethanol fuel sit for a while as it tend to attract moisture (especially bad if you live in a high humidity climate). The water-holding capacity of E10 fuel is notable as E10 can hold approximately 0.5% water at 60°F (.64 ounces in a gallon, or 12 ounces of water in a 20-gallon gas tank). Secondarily, it acts as a solvent which can dissolve and loosen deposits that are present in the tank and fuel system. If using Ethanol and you don't drive your car frequently I'd make sure to store it with a full tank. I'd also use a fuel stabilizer and run the engine for 10 minutes to make sure the stabilizer is fully introduced into the entire fuel system.

      I wouldn't alternate between non-Ethanol (Clear) and Ethanol (i.e. you have a half tank of Ethanol and you fill up with Clear) as phase separation may occur, resulting in an approximately 50/50 ethanol and water layer at the bottom of the fuel tank. Make sure you are almost empty before switching over. Bottom line is pick one and stick with it.

      As far as octane goes, buy the highest rating you can. In my area Clear fuel is rated at 93 octane while regular Premium (E10) is rated at 92 octane. For track days I usually run two 32oz cans of Torco F500010TE Unleaded Fuel Accelerator. This raises my octane level to around 100 and lowers the potential for high rpm detonation. I don't use it for normal street driving situations.

      With your engine rebuild I'd do the obvious and replace the fuel filter and flush the fuel tank.


      • #4
        The fuel tank has been fully tanked, cleaned, and repainted by a radiator shop and all of the fuel lines, filters, and sender pump are new. The only part of the fuel system that isnt new is the main filler neck, the in-tank pump, and the injectors, all of which were reconditioned. I'm going to call Korman later today to get Carl's input. Hoping to start her up this weekend once I get my brakes on and the system bled.