Ethanol blended fuel up to 10% can be run in modern power equipment but problems arise if ethanol blended fuel stands in a fuel system for more than 60-90 days. Gasoline which is organic in nature will begin to decay due to high amounts of oxygen in the ethanol. Also the fuel will begin to absorb moisture from the air because ethanol is hygroscopic and it attracts moisture. This added moisture can lead to phase separation. What separates from the fuel is the water with the ethanol attached to it. This will cause the metal components to corrode because water and ethanol are highly corrosive when together. Also older power equipment cannot tolerate ethanol at all and newer equipment can tolerate ethanol both when fuel is left to stand for long periods of time even these new materials can decay due to the ethanol content. Again if the fuel is consumed in a short period of time and left to set allot of the problems are avoided. The reality is that not everyone will drain their fuel system all the time and people need to be aware of these problems. By adding Ethanol Sheild to the fuel, it will not matter how long the fuel sits before use.