Ethanol free gas for Mercruiser

[ZafSC]

Hi all. I used the live in South Carolina and recently moved to New Hampshire, Massachusetts area. I have a Stingray 2006 Mercruiser 5.0 Mpi inboard stern drive. In SC, there was no shortage of gas stations with no ethanol gas supply. But in new england area they are practically nonexistent. Boat owners that I talked to so far, they use regular 87 Octane gas. I am highly surprised. Isn't that supposed to shorten the engine life? They only sell no ethanol gas in specialty stores like Home Depot about 5 times the price of regular gas.
What is the right thing to do here?
Thanks

 

[04fxdwgi25]

Here where I am in NC, they sell the ethenol free gas in about 75% of the gas stations and it's usually 91 or 93 (have seen some 89). About $0.50 per gal more than ethenol gas of same octatane rating.

On what should you use? Low performance engine = low octane.
I personally use 91 or 93 non-ethenol, depending on what is available, in my 454 Mag. Just my preference and it does give me lower fuel consumption, so it's like having a larger fuel reserve.

 

[Lou C]

I use what we can get here in NY which is E10, but I use at least 89 octane and at gas docks they sell only 93. Have not had a lot of problems with it over the years in the boat but I do use stabilizer. The E10 is more of a problem in small engines and on those I drain the carb bowls at the end of the season.

 

[Scott Danforth]

. Isn't that supposed to shorten the engine life?

not a chance of that happening.

E10 has been around for over 34 years. in fact Henry Ford used ethanol for fuels over 100 years ago.

now, some stations that have blend pumps have had issues where the E10 was actually closer to e40. and anything over 10% ethanol on small engines (lawn mowers, etc) will cause them to overheat.

however your boat will run perfectly fine on pump swill. in fact, that is what the MPI fuel system was designed around.

 

[Pmt133]

I've never had an ethanol related problem boat or car that wasn't caused by my own stupidity. Letting it sit for two or three years can do it to a carb. Otherwise I've never worried about it....

 

[nola mike]

I've never had an ethanol related problem boat or car that wasn't caused by my own stupidity. Letting it sit for two or three years can do it to a carb. Otherwise I've never worried about it....

I always get a kick out of anti ethanolers that act like E0 can sit indefinitely and not turn to apple juice. (I know that isn't what you're saying here).

 

[Lou C]

If you're concerned or just curious, you can get an ethanol test kit to make sure the fuel you are using doesn't have more than 10%.

 

[ZafSC]

What about the problem of Ethanol separation (they say, phase separation) where fuel separates from water and water going into engine can be harmful. Doesn't anybody have a problem with this, short term or long term? Thanks

 

[ZafSC]

If you're concerned or just curious, you can get an ethanol test kit to make sure the fuel you are using doesn't have more than 10%.

I believe a reputable gas station has less than %10. I am just worried even that amount maybe harmful my boat engine.

 

[Pmt133]

What about the problem of Ethanol separation (they say, phase separation) where fuel separates from water and water going into engine can be harmful. Doesn't anybody have a problem with this, short term or long term? Thanks

You use a water separating fuel filter. Unless you get contaminated fuel or water gets into your tank via a bad fill or vent.... it typically isn't an issue especially if you replace the filter regularly. I've never had any water in any of my tanks or any filter I've pulled.

To put it another way, if somehow enough water got in the tank to cause an issue... the least of your problems would be if it's ethanol fuel in there or not.

And just for fun, if it did phase separate, the light phase would be pure gas.

 

[nola mike]

What about the problem of Ethanol separation (they say, phase separation) where fuel separates from water and water going into engine can be harmful. Doesn't anybody have a problem with this, short term or long term? Thanks

You only have phase separation when too much water gets into the fuel. Ethanol has the ability to absorb some of this water before it separates. E0 can't absorb any water so any water that gets in the fuel is always separate.

 

[Scott Danforth]

I believe a reputable gas station has less than %10. I am just worried even that amount maybe harmful my boat engine.

its not. you are literally worried about nothing.

What about the problem of Ethanol separation (they say, phase separation) where fuel separates from water and water going into engine can be harmful. Doesn't anybody have a problem with this, short term or long term? Thanks

phase separation generally doesnt happent unless you let the fuel sit for a long time at really low temperatures.

again, you are worried about nothing.

 

[dingbat]

What about the problem of Ethanol separation (they say, phase separation) where fuel separates from water and water going into engine can be harmful. Doesn't anybody have a problem with this, short term or long term? Thanks

What the snake oil marketers don’t want you to know….

https://www.epa.gov/sites/default/files/2015-09/documents/waterphs.pdf

 

[Lou C]

Im in agreement with the above posts. Besides the boat & our vehicles I maintain 9 different small engines:
5 two strokes
4 four strokes
All have been run on E10 gas with stabilizer. I’ve had to clean out a few carbs but since I installed fuel shut offs on the 4 strokes with bowl carbs & drain the bowls fully for storage I have not had any problems with them. The 2 strokes with the little cube carbs I just start once a month.
The only thing you may run into is this, ethanol is a good solvent and it will clean out the fuel tank. This can clog fuel filters so keep a few spare filters on hand. The year we had to change over I found some red gunk in the fuel filter. After that, nothing. Every year I change the water seperating fuel filter & dump it in a mason jar. The fuel is crystal clear.
I could run my yard equipment on “engineered fuel” but it runs fine on e10 pump gas and my own 50:1 2 stroke mix. This is like 20 years worth of data on e10 fuel use. BTW the engineered fuel is like $8.00 a gallon!

 

[Scott06]

Im in agreement with the above posts. Besides the boat & our vehicles I maintain 9 different small engines:
5 two strokes
4 four strokes
All have been run on E10 gas with stabilizer. I’ve had to clean out a few carbs but since I installed fuel shut offs on the 4 strokes with bowl carbs & drain the bowls fully for storage I have not had any problems with them. The 2 strokes with the little cube carbs I just start once a month.
The only thing you may run into is this, ethanol is a good solvent and it will clean out the fuel tank. This can clog fuel filters so keep a few spare filters on hand. The year we had to change over I found some red gunk in the fuel filter. After that, nothing. Every year I change the water seperating fuel filter & dump it in a mason jar. The fuel is crystal clear.
I could run my yard equipment on “engineered fuel” but it runs fine on e10 pump gas and my own 50:1 2 stroke mix. This is like 20 years worth of data on e10 fuel use. BTW the engineered fuel is like $8.00 a gallon!

this is exactly right only place I have had issues with E10 is when it sits in a generator etc.

I run the boat on non ethanol because that is what the marina sells and I dont want to lug cans to fill a 37 gal tank.

Jetski I use E10 from the pump because I dont take it that far to go to the marina that is full of weeds.

We use both a lot so the fuel only sits from last fill up to the spring. Around labor day I start adding stabil so it is fully in fuel system. Never find anything in the fuel filter but change it every fall. Do the same with all my lawn equipment no issues there

 

[Lou C]

The only exceptions to my draining the 4 stroke carbs:
Generator I start once a month & run it & put a load in it with my wife’s hairdryer to make sure it makes power
Briggs & Stratton lawn mower with the old school pulsa Jet carb that sits on top of the gas tank; these will rust internally if you leave them empty; I leave mine full and have had to rebuild the carb a few times in 30+ years on that one.
Also, my 2 stroke chain saw I run out of fuel & drain because it hardly ever gets used. The rest of the 2 stroke engines get used regularly. I’ve been doing this for 15+ years with E10 and if it didn’t work I’d be using the high priced engineered fuels.
Lastly when I rebuilt the Quadrajet on the boat last time (2018) it was very clean inside. No corrosion, no deposits etc.

 

[Scott Danforth]

part of testing equipment for OPEI is a phase-separation freeze test of the fuel tank.

This is a requirement for all plastic fuel tanks on lawn mowers, snow throwers, etc it takes a lot of work to get E10 to phase separate for testing. usually leaving the tank in the cold chamber for well over 2 weeks at below freezing temperatures

if you shake the tank, you start all over

In the real world, its generally not a problem.

 

[Chris1956]

Some sound advice here. Let me add my .02. For engines that sit like generators, pressure washers, etc. stabilize the fuel, shut off the fuel flow (if you can), and run those single carb motors dry. If no fuel shut off, drain the gasoline, run the motor dry and toss an oz of 2 cycle oil into the empty tank to keep the rust down.

For multi carb engines, stabilize the fuel and run the engine a couple of minutes. Leave carbs full of stabilized fuel.

A couple of shots of fogging oil when running the engine helps lube 'em up. Not sure if this is really necessary, but it has no bad side effects that I have seen.

Ethanol in gasoline is actually a good thing, along with being inevitable. The alcohol absorbs some water and allows it to be burned w/o issue. Remember the old days when your car fuel line froze from water in the fuel. You were out there in the freezing cold adding dry-gas to the tank?

 

[Eischman]

https://www.pure-gas.org/
Every state is listed here.

 

[04fxdwgi25]

Been running std ol e10 regular pump gas, with stabilizer for the winter, in my '91 (33 year old) wheel horse tractor with an Onan 20 HP engine since I got it. Only fuel related problem I have ever had was the plastic fuel tank had a stress crack in it and couple of hoses dry rotted. Never drained it out or dumped the carb for the winter.