Effects of Ethanol
 

Looking for some input from the OSO fam. I've heard various stories on how ethanol in our gas has had an adverse effect on our marine engines and other boat components. I've also heard that it degrades certain materials till failure (isn't this why old skaters have their tanks replaced?). How would I know if the engines I own have parts/components that will fail with ethanol gas? I would hate to find out the hard way. If I am off base on my ethanol assessment, please fell free to set me straight. I have 99 mercury pro max's. Any input is appreciated....I don't have a lot of access to ethanol free gas in my area.

There are many variables that 99% of the people preaching this probably don't know or understand. Its an easy blame all IMO.

Guys are running e-85 or straight ethanol on some pretty big horsepower applications. You substantially need more ethanol than gas to make the same amount of power. Bigger injectors - fuel pump - jets ect. (It has the octane rating 110+ so its great for boosted applications)

On a 2stroke it is believed high ethanol gas can dilute the oil mixture so it would need to be richened up oilwise.
Ethanol is hard on some fuel orings - lines etc.

What is a big difference is the air fuel ratio when flip flopped with no tuning. Switch a normal well tuned motor to ethanol with no change and you are causing a lean condition.

As far as skater tanks - I have no idea. Curiously awaiting an answer from someone that knows much more than I.

Ethanol is basically a solvent chemically, and yes it breaks down the resin used in the old skater tanks. It also cleans our old gas tanks of deposits left by standard fuel and send them up the system, deposits normal gas wouldn't touch.

However, ethanol has quickly become a scape goat for every blown engine and fuel problem that has happened since ethanol has been mixed with gasoline.

One thing to note, ethanol is basically dry gas. It absorbs water and moisture (hygroscopic) so in a boat with open fuel vents kept in the water it can be a problem over time. I do use 10 percent ethanol in my boat 93 octane, but I now fuel for the occasion and try to guess what I am going to use each weekend. Occasionally I will use non ethanol rated at 91 octane but that puts me at the edge running 8 lbs of boost.

Ethanol fuel is also actually dirtier on a microscopic level (more deposits) because it is not refined as far to reach the target octane, they reach the target by adding high octane pure ethanol to a lesser refined fuel.

These comments are based towards the 10 percent at the pump, not the higher blends which should never be used without modifications.

Many posts on this here on OSO.

Ethanol in fiberglass tanks is a big problem.

You must do something to treat the ethanol gas so it doesn't tear up everything. I've been running the Star Brite product for many years and have been very happy with the results. The one time I didn't use it, (got ethanol fuel when it was not advertised as such) it ruined several parts of my fuel system.

I love ethanol.:poopoo:

Lol I figured a few of you big HP guys were using it... Cars have been playing with it for awhile.

Since lead was banned in the USA back in 1974 at the gas pumps - lead provided octane in the fuel as well some other benefits for a engine. A form of an alcohol has been in the gas supply since 1975 in a lot of major cities around the country.

Also alcohol blended fuel 5% to 10 % was used in many northern states fuel blends in the winter called winter blend gas since the 80's. Ethanol alone has an octane rating of 112. It also is used to provide octane in the fuels especially today.

Never use gas that water has formed or somehow found its way into your fuel. The alcohol drops out along with the water (phase separation) of the gas - hence a very low octane fuel is left.

I have heard of people pulling the water out and then using that fuel in whatever app. Again that fuel will be of a lower octane value for sure. Detonation is very possible.

I Don't Think You'll Have Any Problems
 

I've got a 1998 Promax 200ss and have used the 10% ethanol gas since day one without any problems.

Motor has close to 300 hours on it and runs like new.

Forgot back in the late 70's and in the 80's alcohol in the fuel was called gasahol fuel here in the USA. The deal with boats is they are better running than sitting no matter what fuel you use.

The only way you would know of the engine parts are compatible with ethanol is (A) the engine is rated for 10% ethanol, or (B) go part by part and check it against the manufacturer of that parts compatibility list (most parts easier to replace).

Compatible or not, it is not a good idea to store gasoline with ethanol in tanks vented to the atmosphere. The Ethanol will attract water vapor in the air, and then you have corrosion problems.

Michael