Media & News

Blog Posts
Ethanol & Water Do Mix – Same Story, Different Lake

March 10, 2016


Some of my fondest memories as a child are from the water. Whether that be fishing, skiing or just buzzing across the lakes in our family’s boat. I grew up in Kansas, and none of those memories involve boat breakdowns. You see, I grew up on a farm, and am a second-generation ethanol promoter. All of these things I enjoyed on the water were powered by ethanol-blended fuel, whether that be in the 1980s, 1990s or in more recent years. I was around fishing boats, ski boats, a see-doo, a waverunner and a wetbike – all powered by E10. None of the engines in these marine applications had a single fuel-related issue. In fact, one of those boats sits behind my father’s house today and still runs as originally advertised a few decades later. Since the passage of the RFS in 2005, the efforts of some groups like BoatUS would lead you to believe that memories like mine have all but disappeared. They want you to believe that any amount of ethanol is too much for a marine application and a breakdown is almost guaranteed. Let’s break their claims down.

  • BoatUS claims the ethanol will cause engine damage because of phase separation and ultimately performance will be reduced.
    • Phase separation only happens when water is present in the fuel and hits a certain percentage. This causes the ethanol to fall out of suspension and bond with the water at the bottom of the tank. How does BoatUS believe this phenomenon happens? Their claim is that ethanol can mysteriously pull water from the air. The fact is that even Mercury Marine says that doesn’t happen, and all fuel is subject to water issues, regardless of ethanol content. Ironically, I pulled this excerpt from the website of BoatUS: “Mercury Marine, which recently hosted a Webinar on ethanol myths, noted that ethanol does not ‘grab water molecules out of the air.’ It is hydrophilic, which means ethanol holds water. With regular gasoline (E0) as well at E10, the primary cause of water collecting in tanks is condensation on tank walls. But unlike E0, which can absorb almost no moisture, E10 can hold up to half of one percent of water by volume, and the water molecules will dissolve in the fuel. The ‘solubilized’ water will bypass the water separator and burn harmlessly through the engine.” (From December 2011 - In fact, when asked about phase separation on the Mercury Marine website, they respond that when introducing E10: There should be no difficulties if the tank is clean and free from water.” ( The point? If owners and operators keep water out of their fuel system, they will never have an issue with phase separation and according to information from BoatUS, without phase separation, you shouldn’t have any engine issues.
    • Onto performance, according to Mercury Marine: “outboards should experience little or no decrease in performance due to gasoline fuels containing up to 10-percent ethanol when operated according to Mercury’s standard recommendations.” (
  • Their next claim is that owners and operators of marine equipment prefer E0 and that fuel is disappearing. It is very easy to track the number of stations offering E0, and that number has grown exponentially the past couple of years
    • Oil refiners have said over and over that they will provide the fuels that customers demand. If there is really an open outcry for E0, they will provide it. In fact, the American Petroleum Institute (API) claims E0 consumption is up and more stations are starting to offer it. Here is their release touting it:
    • In a recent hearing on Capitol Hill, Senator James Inhofe (R-Okla.) bragged about E0 popping up all over his home state. BoatUS needs to follow the fuel business a little closer, as the reality of the marketplace is much different than what they are claiming.
    • Before we move on, let’s consider if that were indeed true. Even if E0 is being forced out of the market, why is it really an issue, when all boat engines manufactured since the 1990s are approved by the manufacturer to use blends of ethanol up to E10 (or 10% ethanol). Is BoatUS insinuating that the marine engine manufacturers are not building their equipment to the standards required to use today’s modern regular unleaded? I hope not and I think the manufacturers should be concerned with those claims.
  • BoatUS claims to also have done a recent survey, with half of the respondents claiming ethanol has damaged their engine. While they have not shared the survey questions or results publicly, one has to wonder why those individuals are not filing warranty claims, since E10 is approved by the engine manufacturer. Why would an engine manufacturer approve the use of E10 if they thought there was a legitimate risk of damaging the engine?
  • Their next claim is on E15, and their concern about that fuel in the marketplace. E15 is available at less than 1% of gas stations today. They should have more concern with diesel, kerosene and other non-approved fuels that are found at thousands of stations nationwide. E15, by federal law, has to be clearly labeled showing what vehicles/engines can use it. There is also one unique part about those stations offering E15--they all offer E10, and in some cases E0.

One has to wonder the motivation of BoatUS to make these claims, all of which can be minimized in the real world. I can only conclude that it is nothing more than a membership drive. One has to also wonder about outside funding when they partner with the American Motorcyclist Association (AMA), a group that has been clearly documented taking money from Big Food and Big Oil. If you want to learn more about ethanol and marine applications, read your owner’s manual. Maintenance is critical, and guidance from the manufacturers should be followed. Listen to the companies that built the equipment, not those that have agendas. If you would like to learn more from our perspective, please follow the link below to the RFA website and view our information on ethanol in marine applications. You will see stories on world speed records on ethanol, how ethanol has helped some boaters win national championships, how E10 is the preferred fuel of the National Boat Racing Association and more. The days of fun on the water are far from over and together, we can combat this recent raft of misinformation.