Fuel Degradation Ethanol vs Non Ethanol vs Stabilizer

[Midnightsun]

Found this video which really shows what is going on. Does last for 13 mins but well worth the watch. Definitely an eye opener to say the least.

[Cooler]

Thanks Hans, that was really interesting. Although these tests were done with 9 mo. and older fuel, I have seen ethanol added fuel degrade much sooner. My mechanic did a test with what he thinks was 30 day time lapse, and that fuel had already separated. I say "he thinks" only because who knows how long that fuel sat in a tank or transport time. Still 30 days was a short time in any situation. Unfortunately, every day there are more marinas converting to ethanol fuel for whatever reasons. It boggles the mind when you consider these tests were done on a lawn mower engine. How do you think that translates to the high performance engines we are running? er

[km1125]

Source of the post
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My mechanic did a test with what he thinks was 30 day time lapse, and that fuel had already separated.
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Time lapse doesn't really have to do with separation. The separation occurs due to settling, and when the water content gets high enough to combine with the alcohol. You can do separation just by putting some water in some fresh gasohol, shake it up and let it settle (in fact, that's one way to test the percentage of ethanol in the gas, just by measuring what's left).

Time will affect the overall quality of the fuel though, especially if it's allowed to vent to the atmosphere. The lighter ingredients in the gas (or gasohol) will evaporate and leave the tank via the vent. The larger the vent, the more evaporation you get, and the more heat/cool cycles you get, the more flow in and out of the vent. That process also allows more moisture to be drawn into the tank.

I would have liked to see those tests done with various stabilizers. Not necessarily to see what helps Ethanol, but just gas storage in general and how the various products compare.

[bud37]

Nice video , interesting to see the images of the different corrosion deposits......the same pics have been seen here numerous times from people with plugged screens/ filters and engine run problems.

IMHO that stuff has no place in marine gas engines unless you are using your boat pretty much every day of the year and have a new power plant that is designed for that type of fuel and plastic tanks.

[RGrew176]

We are very lucky here in my immediate area. I know of no marinas that sell an ethanol blend. All of them are advertising ethanol free gasoline. One can only hope there is not false advertising going on. I hope it remains that way.

[Viper]

I wouldn't expect stabilizer to save any fuel past 6 months. Heck I don't like running anything over three months. After all, it starts to degrade as soon as it leaves the refinery, and today's fuels start going stale after about 30 days, but we don't have much of a choice in our neck of the woods. If I could boat all year round, I wouldn't have to worry about stabilizer or old fuel.

Most marinas around here are still ethanol free but it's just a matter of time before they all switch over. Ethanol free is becoming more expensive and every year fewer suppliers carry it. The ethanol is definitely nasty stuff for our application. Speaking of time lapse, you'd be amazed at just how fast the ethanol will draw moisture out of the air. On a hot and humid summer day, put some in a glass bowl and within minutes you'll see it starting to cloud up as it sucks in moisture. There is no time lapse, the process starts as soon as the fuel is exposed to air, that's why you can get water from filling up at a gas station, it's in their tank because it's vented to atmosphere. What takes more time is phase separation where it's collected enough water to reach saturation and the water and ethanol finally separate from the gasoline and sink to the bottom of the tank and is the first thing to be sucked up by your fuel pump if the separation is high enough.

Just a note while we're on the subject of additives; don't know how much this affects our members here but anyone that has catalyst engines must ensure the additives are compatible with catalytic converters, everything from engine oil and oil additives, to fogging oils, and fuel additives or you could be replacing the catalyst elements, and let me tell you they are way more expensive than automotive ones. Having said that, most of these products now fall under the compatible list as they were reformulated for automotive catalyst applications years ago. Even so, marine engine OEMs only recently and long after the introduction of their catalyst designs have labeled their oils and additive products as "now" compatible with catalyst engines, seemingly indicating recent formulation changes to accommodate the new design. Ah the marine catalyst engine....it's a whole new ball game and set of rules/dos and don'ts. In short, be very careful!!

[mjk1040]

So! Here in NY where I am with non ethanol fuel, we lay up for 6>7 months, do we fill our tanks before lay up or leave them low and put fresh fuel in the spring? From what this video shows, I'm thinking fresh fuel in the spring is the way to go and deal with what condensation may or may not form in our tanks. If anyone knows of a chart showing shelf life of fuels today it would be interesting to see. I'm thinking after 30days of storage things are deteriorating quite rapidly. Thanks Hans for sharing this, I have found this guys testing to be very informative on many different products out there. Maybe we can have him do one on a moisture removers for fuel?

[Viper]

Considering a gallon E10 ethanol blended fuel can absorb 3/4 of an ounce of water before it reaches its saturation point, that would be 150 ounces in 200 gallons of fuel. Considering the effects are cumulative and adding to what you already have in the tank at every fill up, that's too much water for me, and too long a lay up for today's blended fuels so I prefer to leave the tanks empty for the winter. Filling to an amount that you'll use up quickly in the summer is smart too as summer temps/conditions accelerate the problem. Unless you're planning a long trip, given the potential problems, I don't understand the logic behind filling up with $1K of fuel only to have a lot of it sit in your tank for months or more than a year, especially if you're using a blended fuel that's designed for the automotive industry and expected to be used withing a couple of weeks at the most.

If you can't get non blended fuel, at least get E10 and stay away from E15 or E20. Can you imagine the effects of E85 that flex fuel vehicles are rated for?

[bud37]

The alcohol is the moisture remover we used to add to the car in the winter,( gas line antifreeze). What the heck is going to happen with all this used , bad, out of date gas on the marine side ? Example...I drained the tanks this year....had to.
Maybe Safety Clean/Clean Harbors will have a solution for what I see as an environmental mess and this corn subsidy is another topic. How can we be expected to foot the bill for all this tank changing, excessive maintenance including gas removal etc etc etc. There are a lot of boats out there, a lot...

Consider what may happen when you buy a new to you boat and the previous owner may have saved money by putting his own gas in from the local "fillin" station.....how would that be surveyed ?

Now consider, how do you make sure that fresh gas in the spring is actually fresh.....it may have been in the storage tank all winter as well.....hmmmm.

[Midnightsun]

What is the consensus on Diesel? I know there is no ethanol however is it as sensitive to time as gasoline? I do add diesel stabilizer however after watching this on gas I wonder how effective it really is.