E10 Fuel Tank Storage Question

Friar

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Hi All! I am looking for some opinions on a course of action concerning winter storage of E10 fuel in the fuel tank of my Bennington.

All my reading/research of forums indicates that it is best to winter store the fuel tank full of fuel. The reason is to prevent accumulation of water (condesation) caused by day/night temperature fluctations. Additionally fuel stablizer (Sta-Bil, SeaFoam) should be added to mitigate the problems of fuel/water separation inherently caused by the composition of E10 fuel over time (although I am not sure what length of time is considered critical for this to occur). The combination of these two aspects is the reason I am looking for opinions.

My situation is that I have approximately 13/14 gallons of fuel left in my 21/22 gallon fuel tank which has been sitting there since the end of August. I was not able to use the boat since August because of the drought in Texas and I could not launch it anywhere. My last feasible chance to find a useable launch site was the Thanksgiving weekend and weather and time prevented that chance. So it looks like my next realistic chance will be mid to late February. At that time the fuel I have in the tank will be at least six months old. Last February I used E10 fuel that was three months old without any discernable problem.

I am just not sure what is considered "old" for E10 fuel ... 1 month, 3, 6, 12?? Anyway, the options I can think of are:

1. Do nothing. (easiest, most worrisome.)

2. Add fresh E10 fuel and fuel stablizer to what I currently have to fill the fuel tank. (easy, not sure of effectiveness).

3. Siphon off the existing 13/14 gallons (burn in my truck now) and fill up tank with fresh E10 and stablizer. (some work, fuel will only be 3 months old in Feb).

I am leaning toward option 3. I would also run the motor on muffs to use up old fuel in the fuel lines and during the rest of the winter months.

I would appreciate any opinions or other ideas anyone can give me. (PS - Although pure gas (E0) exists in Texas, the locations are not anywhere near me or are at marinas where I cannot launch.)
 
I have read where E10 will begin to turn into a varnish like substance within 2 weeks. If I were in your shoes, I would immediately hook muffs up to my motor, add fuel stabilizer (heavier than recommended with Sta-Bil marine formula) and run for a minimum of 15 minutes. Shut the motor down and top off tank with fuel to prevent condensation. That should get you set to store your boat. I personally run fuel stabilizer in every tank in the event an unforeseen situation like yours occurs.
 
I know this is a contested subject, but if you go to your outboards website you might get some additional facts. I did a fair amount of searching and then went with the guidance on the Mercy outboard site. They reccommend adding a stabilizer, running the motor until the tank is near empty or after running for 10 - 15 mins draining to get empty. If empty can not be obtained then completely full (treated fuel) is the next best option. It seems everyone agrees partial full is not a good idea as it offers the most exposure to condensation.

I have used the completely empty method on a motorcycle tank that was prone to e10 swelling, and that worked better then completely full for storage.

I have read where E10 will begin to turn into a varnish like substance within 2 weeks. If I were in your shoes, I would immediately hook muffs up to my motor, add fuel stabilizer (heavier than recommended with Sta-Bil marine formula) and run for a minimum of 15 minutes. Shut the motor down and top off tank with fuel to prevent condensation. That should get you set to store your boat. I personally run fuel stabilizer in every tank in the event an unforeseen situation like yours occurs.
 
I believe the most important step is running treated fuel through your motor for 10-15 minutes as dmctruby mentioned. Remember, stabilizer in the tank will not treat remaining fuel left in the fuel lines. You want all untreated fuel to be burned up in the fuel system and replaced with treated fuel so the ethanol does not begin to varnish within the fuel system.

I would assume Mercury then wants you to run the motor dry of treated fuel.
 
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Do you have any older engines that you could use this old e10 fuel in? I would be just as worried about using it in a 2010 truck, but old cars and engines seem to be more forgiving of old fuel. Then leave it empty for the winter.

I normally put stabil in with the fuel while it is new and fill the tanks for winter storage and have not had any problems.
 
I think a big part of the e10 issue is what it does to plastic and or rubber components like gas tasks and o-rings/seals/gaskets. It is known to swell and deform those, so if you can keep them dry (aka gas tank empty) or treated (lines/o-rings/seals) then less trouble down the road. For sure as was stated previous step one is to get any gas in the system treated by running storage treated fuel through it.

Do you have any older engines that you could use this old e10 fuel in? I would be just as worried about using it in a 2010 truck, but old cars and engines seem to be more forgiving of old fuel. Then leave it empty for the winter.

I normally put stabil in with the fuel while it is new and fill the tanks for winter storage and have not had any problems.
 
If #3 is a viable option, do that.

BTW, while E10 can cause problems it's not quite the monster it's made out to be. Modern automotive engines are made to handle it, modern boat engines... Well, if the owners manual says not to use it then don't use it. If you are going to use it anyway, consider replacing any rubber hoses with the newer Teflon stuff.

I'm not saying this because I'm trying to convince you E10 is harmless, because that's too situationally dependent for a blanket statement. I'm just saying there's no need to panic.

Drain out your E10 fuel and burn it in the truck, dump 5 gallons of Stabil treated non-alcohol gasoline (4oz Stabil) into your boat tank, run the engine off the garden hose for a few minutes and then relax. Maybe do an engine fog. That'd be a good idea. (you can buy the stuff in aerosol cans at your marina) Do that and you'll be fine for the spring. Just top her off with good gas and put her in the water.
 
I agree you don't want to leave tank half full, but omg people E10 isn't auto death! The biggest place it causes problems is actually in older vehicles that don't have the new types of seals and hoses, granted in some small engined recreational vehicles might have issue because I'm told it burns hotter than normal fuel, you won't have any issues in your cars and trucks! Most of our vehicles are approved for 85% ethanol! Not 10%! As for it turning to varnish in a couple weeks, use your heads, obviously the government and engine manufacturers wouldn't approve of a fuel that had such a short shelf life and could cause such issues! I mean, based on that info, if you went on a cruise you'd have to put stabilizer or drain your tank at the airport so your truck wouldn't blow up if you tried to start it when you got back!

I've run E10 in my lawnmower, whipper snipper, leaf blower, all for over 7 years now, put stabilizer in before winter and NEVER had a prob starting in spring, and since I'm in Canada, they won't get run for probably 7-8 months.

E10 gets such a bad rap nowadays because mechanics will say, well it's that fuel that caused it to break, or that hose to leak, or the seal to let loose, stuff breaks, always has, always will. My buddy had an SVT Cobra mustang , blew 3 engines in it, there was no ethanol fuel back then, but I'm sure if there had, they'd have blamed it!
 
Bulldogs, No one here implied that E10 was "auto death" as you put it and most of our vehicles are NOT approved for E85. There were 9 million E85 vehicles on the roads of the US in 2009 or 3.3% of our total vehicle count. In the same year, only 10% of vehicles sold new were E85 capable.

To your final point, I'm glad your are happy enough to trust your government to do what's in your best interest. Me? I see dollar signs in my government's eyes.
 
e10 can have some very harsh effects even on today's cars/boats/autos. My very expensive newer motorcycle went through two gas tank replacements due to swelling. My expensive lawn equipment (new stuff) has had fuel system recalls (gas caps/tanks deforming and seal issues).

The issue is why risk water absorbing into places you don't want water going too, run it treated and drain the rest if it is going to sit more then a few months.

quote name='spinzone' timestamp='1322658622' post='5107']

Bulldogs, No one here implied that E10 was "auto death" as you put it and most of our vehicles are NOT approved for E85. There were 9 million E85 vehicles on the roads of the US in 2009 or 3.3% of our total vehicle count. In the same year, only 10% of vehicles sold new were E85 capable.

To your final point, I'm glad your are happy enough to trust your government to do what's in your best interest. Me? I see dollar signs in my government's eyes.
 
Bulldog, you have way too much trust in goverment. They did not mandate e10 because it is good for car and boat engines, they did it for special interests(enviromenalists and farmers lobbies). The 2 main problems with e10 are damage to lines and seal (this has been taken care of on newer vehicles) and Phase separation. Gas floats on water and the engine draws from the bottom of the tank. When a new car gets water in the fuel line the car dies and needs to be towed and the repairs can be very expensive $1000.00) because the fuel pump is in the tank and has the fuel filter in the fuel pump and the tank needs to be cleaned. This is why I don't recomend putting old e10 fuel in his 2010 truck. If he burns this gas soon in an older lawn tractor, 4 wheeler or old truck it will be mixed with existing fuel in the vehicle and if there are problems,it is much easier to fix. As for leaving the tank full or empty there are good reasons for each method, so I won't get into that.
 
The biggest place it causes problems is actually in older vehicles that don't have the new types of seals and hoses, granted in some small engined recreational vehicles might have issue because I'm told it burns hotter than normal fuel, you won't have any issues in your cars and trucks!

You're right that older vehicles have more problems and you are correct as to the cause. However, it actually burns cooler than regular gasoline. Also, I don't think this is an area for blanket statements... Let the owner's manual be your guide. It's true that in most cases vehicles built in the 21st century do just fine on E10, but nothing is certain until you check your manual.

Most of our vehicles are approved for 85% ethanol!

That's not actually true. It IS true that most new fuel systems can handle E85 due to their updated components, but that's not the same thing as being able to USE the E85 blend.

Really, its a shame about the way we were introduced to it... E85 is perfect for very high compression engine with long rods and TDC dwell times; not to mention high pressure forced induction, especially turbocharging and Roots style superchargers. But the engine has to be optimized for it; not set up as a "Dual Fuel" vehicle.

As for it turning to varnish in a couple weeks, use your heads, obviously the government and engine manufacturers wouldn't approve of a fuel that had such a short shelf life and could cause such issues!

This is as close to a political statement as you will ever see me make on this website:

I don't trust my government to wipe its own posterior, and I respectfully suggest that you consider adopting a similar level of cynicism on the subject. As I have stated before, this is something to consult your owner's manual on if for no other reason than to avoid warranty issues.

I too routinely run E10 in my cars and various lawn tools, so your point is valid... E10 isn't "teh debil". Still, prudence in this area is good advice.

BTW, please don't interpret any of the preceding as an attack. It can be easy to interpret disagreement that way on the internet when it hardly ever is.

Well, except for USENET, but that's a different subject altogether. ;)
 
I don't take anything as a personal attack, well I guess unless you said "Hey Derrick, you are an idiot" that I think I would construe as an attack, my comment about the government was more in regards to use your head for a second and think about what it would do to the public and economy if the government mandated the use of a fuel that would turn to varnish in a couple weeks. I am also only speaking from my experience and those of my former customers. Since I ran a Husky/Mowhawk gas station for about six years, of which four we were the ONLY company to have ethanol in its fuel. Untill the government mandated that a certain percentage of all fuel being sold in your location contain ethanol. In all that time, I never ONCE had a customer tell me that the fuel wrecked their car. I did have people say that they wouldn't burn it in their sleds and boats because manufacturer said not to. We actually had documentation from pretty much every manufacturer from ford to Mercedes, to porsche saying that up to e10 was approved in their cars.

In regards to Clark's comment about phase separation, if gas floats on water that what difference is the ethanol making? According to this statement whether or not there is ethanol in the fuel, the gas and water will separate giving the same issue. When I ran the station I know that we had to check the fuel frequently for water in the tanks because it was my understanding at the time that the ethanol would separate the water from the fuel, is that what you mean? Water in any fuel e10 or regular is bad. I think another problem today is that the fuel companies are using a poorer grade of fuel. By this I mean when we were the only ones with ethanol, we sold a 90 octane fuel at the same price as everyone's 87. Reason being that the fuel companies were supplying 87 octane fuel to husky which we would then add ethanol to, making it a 90 octane rating. Since here in Canada only Shell, Petro Canada, and Co-op had refineries they supplies all the others, but once the government mandated the ethanol, they were able to supply an 85 octane fuel, add the ethanol to make it an 87. Most gas stations have ethanol free premium 91 octane. That way they take the 87 regular and the premium 91 with blender pumps and that's how you get your mid grade 89 octane.

The only other thing I like about the ethanol fuel, keep in mind that I'm from Canada, and we hit temps of -45 Celsius and colder, is I have never needed to add gas line antifreeze! Ethanol doesn't freeze! And after all this I will add that I agree, read your owners manual, and do whatever makes ya feel good!! Haha
 
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I guess I could have explained it better, so I'll try again. Ethanol is hygroscopic, which means it pulls water out of the air, so after some time phase separation occurs and a layer of water is at the bottom of the tank where the pickup is. The reason this is a problem for boats more than cars is that we don't use our boats as often as our cars, so there is enough time for the ethanol to pull water out of the air and phase separation to occur in boat gas sitting in the tank. The e10 he has in his boat is untreated and has had enough time to have water in it, since it is old. When he gets it out of the tank it will likly mixup again, but the water is still in it. My backround is as a master mechanic at a Benz dealer and I have worked on serveral cars damaged by water in the tank.
 
Thanks everyone for your responses; I really appreciate getting "collective" thoughts on this issue.

I might have been unclear in my original post - all the fuel I have ever used has been treated with Stabil and Yamahalube to include the existing fuel currently in the fuel tank/fuel lines.

Anyway what I have done is siphoned off as much as I could, refilled with fresh E10, added Stabil and Yamahalube, and will run the engine on muffs about every two weeks during the winter months. Guess I will know in next February whether I have a problem or not (although north Texas winter weather is variable enough that I still might be able to launch before then if we have some signficant rain in the interim)!

"spinzone" - thanks for the links to the websites, although my reading of the Yamaha site just adds to the lack of clarity on the issue - its says there are two recommended options: 1. Fill tank with treated fuel or 2. Drain tank.

Again, thanks everyone and have a happy holiday season!

(PS - "bulldog" - please don't take any offense to any comments - think it is generally safe to say that you "hit a sensitive nerve" among US citizens concerning government and politicans :mellow: )

We still like Canadians especially those with dogs whose ears flap in the wind on their Benningtons :D
 
I never added any alcohol to my gas, although I've known guys with alcohol burning hot-rods who added gas to their alcohol to avoid having to carry around a spray bottle full of gasoline so you could start your car.

I did used to add Toluene to the gasoline I put in my race car. Well, track car... I used to drag race it, but it was a street car.

Anyway, Toluene... That's the stuff they make TNT out of.

It has an octane rating of 114, so if you mix a gallon with 87 octane gasoline you get 100.5 octane. PLUS it has oxygen as part of its chemical makeup and it's pretty dense, so it's a good powerful fuel.

I used to run it in an Impala Police car that I drag raced. I got it down into the low 13's without cracking the engine to add even so much as higher ratio rocker arms.

I will admit to hacking the computer to re-work the timing curve, which is where the higher octane comes in.

I had an idea at one point to rebuild the engine, strap on a X-Trim Vortech blower and run the thing on E85, but I never quite got around to that.
 
Haha, Friar, don't worry about it! :) I don't take offense to comments, I like to be a smart ass and as for politicians, I can't say I have much use for any of them, So I understand the lack of trust in their decision making. I'll try to get another flapping ear pic for ya, in about 6 months or so when the ice comes off our lake!

Eric, I should let you know that I am a Purolator driver, but I like to dabble in some neurosurgery on the weekends, once hacked open the frontal lobe........ Okay! You win! Haha just bugging ya! It's good to know that you have the knowledge, that way when I screw something up, I'll know who my first message gets directed too!!

The funny part is, since I only put premium in the boat, it doesn't actually contain ethanol! Only the lower grades! But I do burn it in my Escalade and all my vehicles before it. As I said in an earlier statement, I do know that a lot of people didn't want to put it in their sleds around here, but since it's been mandated, who knows. Our old premium when no one else had ethanol was actually 94 octane! Some stations actually had the super premium which was 96! I remember one time, we were hosting a snowmobile race that was part of the Canadian circuit, and the "Team Co-op" semi had to come to Husky to get fuel for their generators because it was so cold and the co-op fuel kept freezing up! It was just pretty funny seeing their big rig all decked out in Co-op advertising getting fuel from us! Sorry totally off topic, just a funny story!
 
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