The government's move to renewable energy sources has made fuel purchases for our outdoor equipment a little harder. In order to protect your engine from internal corrosion, you must avoid the new E15 fuel and purchase fuel with an ethanol content of 10% or lower.
What is E15?
E15 is new fuel/ethanol mixture mandated by the government. It contains up to 15% of ethanol as opposed to 10% in E10, which is common throughout the country. Chances are you will see E15 at your gas station this summer. The government mandates the sale of E15. If you read the labels on the pump carefully, it will tell you how much ethanol is contained in the fuel in your area.
E15, like any other fuel, will power your small engine or car. Your engine will function as it did before. Unfortunately E15 is chemically different from pure fuel. It can do damage to an engine or fuel system that have not been built to use it.
To maximize the life of your power tools use only E10 or lower, and add a fuel stabilizer additive to prolong the fuel's storage life.
How does it damage an engine?
The ethanol contained in the fuel has different properties than the fuel itself. Engine and fuel system components can react differently to exposure to ethanol. At best the ethanol has no detrimental effect; at worst it corrodes the material it comes in contact with. The government is aware of this effect. The safety sticker at the top of this article must be displayed wherever E15 is sold.
Designers are capable of building small engines than run properly on E15. If your tool is rated for use with E15 or higher, you have nothing to worry about. As of 2013 E15 is a problem for almost all existing small engines. These machines have not been built to withstand fuel with a high ethanol content. They will take damage if run with ethanol; even once.
Is E10 save to use?
Experience has taught us that E10 or lower is probably save to use in most small engines. The ethanol content is low enough to not damage any internal engine components. It's best to consult your tool's manual for a list of compatible fuel types.
Unfortunately ethanol causes problems when the tool is not in use for a long period of time. The heavier ethanol can separate from the fuel and sink to the bottom. This creates a layer highly concentrated ethanol. Problems with corrosion and plugged fuel lines shortly follow.
To prevent this problem any fuel containing ethanol used in small engines should be treated with a fuel stabilizer additive. Widely available at auto stores and gas stations, the stabilizer slows down the separation effect dramatically making E10 save for use in small engine. As a rule you should tread any fuel that goes into a small engine with a fuel stabilizer. It will increase engine life.
Small engines are typically not built to withstand the corrosive effects of fuel with a high ethanol content. While most engines are fine up to an ethanol content of 10% (E10), E15 should only be used in engines rated for it. To maximize the life of your power tools use only E10 or lower, and add a fuel stabilizer additive to prolong the fuel's storage life.