I will use ethanol. Whatever is convenient. My snowmobiles and boats have no water in their tanks curtesy of ethanol. Ethanol will absorb any water that enters thru condensation. It has its limits. When the limits are exceeded things get ugly. I do take care to prevent water from entering my tanks.
7. Will the use of fuels containing ethanol void my engine warranty?
Fuels containing up to 10 percent ethanol are considered acceptable for use in MERCURY engines. Fuels containing higher levels of ethanol are not considered acceptable for use, and the use of fuels containing ethanol higher than 10 percent can void the warranty.
Ran E free last year. This year I may switch to regular and then go back to non-ethanol for the last month or so before I take it out.
We use our boat just about every day. I think if I only used it a few times a month I would stick to non-ethanol. I use the e-free in my mower, snowblower, etc, but they use so little the cost doesn't add up.
After seeing what ethanol gas did to the fuel lines that disintegrated in my hands on my gas blower, gas trimmer, chainsaw, and gum up the carb in my mower back in the 80's I will never use it in any small gasoline engine. I carried that thought to my boats over the years because you just never know how long that gas will be in your tank .......
We fuel at our nearest marina. It is ethanol free. Since we are lakeside and don’t trailer, we use what hte marina has. If I trailed, I would try to avoid ethanol, but I would also use ethanol gas if traveling and that was what was convenient. That’s largely based on the assumption I’d be using the boat and burning through it in a reasonable timeframe.
Outboard motor manufacturer's have been designing their motors with components to handle ethanol fuel since before the start of this millennium. I say that because my third boat had a 2000 Honda BF115 on it and it had a prominent sticker that said it was ethanol fuel compliant. There were probably some things that didn't go as expected when ethanol was introduced in gasoline in the US (I believe around 2005), but they've had plenty of time to tweak their designs.
That being said, for the last twenty fifteen years or so, I've run 10% ethanol gas in my boats all season and only fill with non-ethanol as part of my end of season storage prep. I would not use E85...yet.
For all my small engines around the house (mower, blower, chain saw, etc), I only use ethanol free and I always add Stabil to it no matter what the season. I just don't go through that gas very fast.
Ethanol has issues both bad and good. The following demonstrates those issues.
My neighbor stored his gas in a big old can under his deck. He typically has only used and stored ethanol free gas in that can. In the end it would become evident that water had accumulated in the bottom of the can. He than filled the can with ethanol gasoline. The alcohol absorbed the water until it could absorb no longer. What happens at that point is that the alcohol separates from the gas. He then had 10% phase separated alcohol on the bottom of the can. From that very can he filled both his lawn tractor and my tractor. What resulted was two dead soldiers in our back yards. Each lawn tractor got about 75 yards before they died.
When I got home from vacation I siphoned the alcohol from the bottom of the tractor tanks. The siphoned alcohol and gas when examined in a mason jar looked like a lava lamp. The machines started but ran poorly due to residual globules of phase separated alcohol. I then added isopropyl alcohol available from the gas station to recombine the phase separated alcohol with the gas. That worked in the mason car and also in the tractor.
My neighbor no longer stores his gas cans outside in the snow and he adds isopropyl alcohol to the gas to absorb what little water enters thru condensation. As an alternative he could just use ethanol.
FWIW I'm running 87 octane ethanol in both a 2000 Yamaha OX66 150HP and a 2022 Yamaha FB115. My servicing dealer says over 70% of his service work entails fuel-related issues. His contention is as long as you run Yamaha Ring Free+ and Starbrite Startron you should have no fuel issues. At end of season I run Starbrite Gasoline Stabilizer (used to be called EZ Store - EZ Start) as part of winterizing both motors. This will be my first season coming out of storage on 115, but I can tell you the 150 fires right up, and shows no indication of fuel degradation.
There was a bulletin just sent out this week, I think, warning boaters to NOT use E15. I know it would be tempting, but the worst is yet to come. Word has it fuel is going to $10/gallon. They are doing some "reprogramming" at some stations now getting ready to deal with numbers that have never been used before. Btw, non ethanol was $4.99 at my nearest carrier this morning. I think our price tolerance is being recalculated.