A. Yes, all current models as well as most engines built since the late 1980s have been designed with fuel system components that are tolerant to fresh fuel containing ethanol up to 10% (E10).

A. No, all of the negative issues discussed below will be increased and may cause major damage to the engine.

A. Ethanol has several properties that contribute to fuel system issues:

• Ethanol is hygroscopic (i.e., it has a strong attraction to moisture).

• Ethanol is a strong cleaner (solvent).

• Ethanol produces less energy (BTUs) than an equivalent unit of gasoline.

A. Ethanol molecules have a stronger bond to water molecules than to gasoline molecules. In the absence of water, ethanol and gasoline molecules will bond. When water is added to E10 fuel, the bond between the ethanol and gasoline will weaken. When the percentage of water in E10 fuel reaches approximately 0.5%, the bond between the ethanol and gasoline molecules will break and the ethanol molecules will attach to the water molecules. This is called phase separation. The ethanol and water molecules settle to the bottom of the fuel tank forming a distinct layer of water & ethanol on the bottom and gasoline without ethanol on the top. As little as 1.6 oz. of water can promote phase separation in 2.5 gals of E10 fuel. The result would be 33.6 oz. of unusable ethanol and water mixture on the bottom of the tank.

A. Several things happen:

A. No, there are no additives or processes that will recombine phase separated ethanol and gasoline.

A. No. The remaining gasoline, without ethanol, will have an octane level below the original E10 fuel’s octane level, approximately 2 ~ 3 points lower. This octane level may be below the requirements of the engine.

A. It is normal for gasoline to leave varnish deposits and for surface corrosion to occur inside the tanks and pipes used for fuel transportation and storage: rust on steel and oxides on aluminum. Ethanol will clean any varnish as well as rust and oxides from any surface it contacts. Gasoline without ethanol does not clean the varnish, rust or oxides. Since ethanol is added at the distributor facilities, it will clean any storage pipes and tanks, truck tanks, gas station storage tanks and your engine fuel systems. The amount of material cleaned from all of these systems can quickly exceed the filtration capacity of filters located in fuel systems resulting in restricted fuel flow. If these clogged filters are not replaced, engine performance is reduced and potential damage to the engine can occur.

A. E10 fuel will produce approximately 3% less power than gasoline. This is not enough to be noticed in most applications.

A. There are many different opinions concerning how long it is okay to store any fuel (E10 fuel or gasoline), 2 weeks, 90 days, ???, before losing the properties that are required for proper and safe operation of your engine. There are too many variables, such as the age of fuel when purchased, temperature, humidity, use of stabilizers and the type of storage containers to accurately predict how long.

A. Total prevention of issues may not be possible but there are steps you can take to minimize the occurrence and severity of the negative affects of E10 fuel: