A quick search about ethanol will wield you plenty of doom and gloom results. Basically ethanol has gained a reputation as the end of all small engines as we know it. It will just destroy your boat motor if you even park next to an E10 pump according to the internet. The truth is that E10 ethanol is not the destructive beast that we may or may not think it is.
What is ethanol? Ethanol is an alcohol fuel that’s distilled from plant materials, such as corn and sugar. Alcohol fuels have been around for years, typically mixed with gasoline in a blend. It all sounds good, environmentally sound, and good for farmers. Honestly in modern 4 stoke motors there is no cause for concern with E10 fuel. There are a few times that E10 can give boaters issues.
First is the initial transition from 100% gas to E10. Obviously the alcohol in E10 is basically a solvent. That means during the initial transition you can experience plugged filters due to the E10 actually cleaning the fuel system. The solution is to watch your fuel filter and maybe keep a spare handy. After a tank or two this problem will go away. Going back and forth between 100% gas and E10 can cause this potential problem to re manifest itself.
Second is called phase separation. This happens when the Alcohol absorbs any water that is in the tank and causes the gas and ethanol to separate. This can only happen if you have excessive water in your fuel system. When this occurs, for whatever reason, the solution is to drain the tank. The alcohol in E10 does a fabulous job for removing small amounts of water in normal operations.
Third and last is the issue that we can control. Long term storage of E10 is just not a good idea because there is no additive made to stop E10 from absorbing and Condensation that occurs and over time we end up with phase separation as discussed above. There are two great ways to avoid this potential issue. First is just fish all the time! Second,and more Realistic, you will want to avoid storing your boat for an extended period of time without draining the fuel.
As you can see the downsides of E10 are not so much different than 100% gas. Its all about proper boat maintenance and common sense fuel management. For those of us fortunate enough to fish all year long E10 presents no issues beyond the initial transition.
As hard as it may be to believe for some of us tenured boat owners to believe there are upsides to E10. These are both mechanical and economical in nature.
First on the economical end of the spectrum E10 is a great help to farmers. A study conducted in Minnesota revealed a 2- million dollar increase in domestically grown corn for ethanol. That’s a single state seeing millions of dollars in additional agriculture related revenue. Also the cost of E10 fuel is much less than 100% gasoline, and I could burn a lot of extra fuel in my truck just trying find a station that sells pure gas.
Second are most, not all, boats get better fuel economy with the E10 over 100% gas. When running E10 you do benefit from a cleaner fuel system due to the cleansing attribute of ethanol.
The bottom line here is that a majority of modern 4 stroke marine motors can see a benefit from E10. Both Mercury and Yamaha make it clear that the newer motors are totally E10 friendly. Now the new E15 is another column but the truth is simply don’t do it!