I am an Automotive engineer and also a Certified Marine Technician from Mercury Canada. When we were experiencing a high than normal rate of fuel system problems, I have check over 10 gas stations here in Thunder Bay and surrounding areas, and they all have Ethanol in the fuel. The percentages averages at 8-9%, at that low end they do not by law have to admit to having Ethanol fuel. Most outboards are test and able to accept up15% Ethanol, no more. To combat the Ethanol a good quality fuel stabilizer is just what the Dr. ordered. It will slow the degeneration of the fuel, which happens within 5-10 days, and also prevent water from accumulating in the fuel tank. Since all the fuel come in from the same depot chances of having Ethanol Gasoline is pretty high. If a station is advertising NO Ethanol or Ethanol Free, its because they are less than 10%. For the cost of an ounce of prevention, a shot of Stabilizer every 10l is worth every penny, because the end results can be catastrophic, we have seen a number of power plants severely damaged.