Ethanol fuel solutions .. thoughts

[slowzuki]

He would be wrong. Condensation in outdoor tanks is a huge problem in vehicles, in furnace oil tanks, in above ground storage tanks of all kinds. This is not a made up issue and he has made some wrong assumptions in his analysis. Essentially the tank breathes during the daily heating cooling cycle, if its temp swing crosses the dewpoint you get water in the tank. The mass of fuel inside means the air space part of the tank swings in temp far greater than the fuel portion, his mention of aluminum being a good conductor etc has nothing to do with the issue, plastic tanks do it too.

A completely empty tank has little thermal mass so it tracks the outside temp fairly well, usually staying warmer if there is any sun on it. So no condensation on surfaces.

A completely full tank has lots of thermal mass but no airspace so no breathing.

Its the partly full tanks that are the problem.

Just reading this The Myth of Condensation in Fuel Tanks

He says, "the water is in the fuel when you pump it", however, he doesn't mention ethanol and I don't know when it was written.

 

[ultrarunner]

He would be wrong. Condensation in outdoor tanks is a huge problem in vehicles, in furnace oil tanks, in above ground storage tanks of all kinds. This is not a made up issue and he has made some wrong assumptions in his analysis. Essentially the tank breathes during the daily heating cooling cycle, if its temp swing crosses the dewpoint you get water in the tank. The mass of fuel inside means the air space part of the tank swings in temp far greater than the fuel portion, his mention of aluminum being a good conductor etc has nothing to do with the issue, plastic tanks do it too.

A completely empty tank has little thermal mass so it tracks the outside temp fairly well, usually staying warmer if there is any sun on it. So no condensation on surfaces.

A completely full tank has lots of thermal mass but no airspace so no breathing.

Its the partly full tanks that are the problem.

I had so much water in my Bantam tank... the car wouldn't start...

It wintered inside an enclosed car trailer and the tank was about 80% full with fresh gas 4 months previous...

This is my first experience with "Wet" fuel.

In gasoline powered sailboats some of the guys would run expensive water separators in addition to additional filtering...

Never seen one on a car...

 

[crazyal]

In most fuel injected cars the gas tanks are sealed so heating and cooling will have no effect on moisture entering the tank. It's even part of the emissions check the car's main computer has to check. If you leave your gas cap loose your check engine light should come on.

 

[Ken45101]

Yep, and don't forget refineries love it because it is government (you and me) subsidized something like forty cents a gallon!

AFAIK, the refineries have nothing to do with the ethanol. They cannot ship ethanol mix gasoline via pipeline, the ethanol is mixed in later in the transportation setup.

Ken

 

[skylarkguy]

A couple useful links for finding ethanol free fuel...user beware of course. I did find that one small outfit sells it in my town in Oregon.

Ethanol-free gas stations in the U.S. and Canada
http://www.oregon.gov/OSMB/news/docs/EthanolList.pdf?ga=t

 

[slowzuki]

Bit more to the story. There is light vacuum applied to the tank to collect vapours while the engine is running but the tank is vented somewhat. The tank is not strong enough to have any significant vacuum of pressure applied. When the tank becomes positively pressurized, vapour goes to the charcoal canister. When air comes into the tank, it just comes in via a one way vent with a particular size. The evap sensors know how much vacuum there is with the size of vent port, when the gas cap is off the pressure equalizes throwing a code as it thinks there is a bigger leak than the designed one.

Yes if you pop the cap at the station the tank makes a little suck noise, but park the car for a few minutes first and the pressure has already balanced.

In most fuel injected cars the gas tanks are sealed so heating and cooling will have no effect on moisture entering the tank. It's even part of the emissions check the car's main computer has to check. If you leave your gas cap loose your check engine light should come on.

 

[groundcover]

Dogballs, I thought the 100LL av gas was going to save my day. Thought it would have been easier to buy Meth though ! " if you bring a bunch of 5gal cans for your 'sea plane' I'll fix you up !" I was thrilled. Switched everything over and within the week was in trouble. Filled my 1.5" 5hp Honda pump, ran fine , left it full and in 3-4 DAYS the tank was empty. A gasket at the bottom of the tank was eaten away. Then two chainsaws started acting up. I called Sta-Bil (I had added that to the ave gas )and one of their engineers called me back and went into more detail than I would ever need as to why the 100LL was great for planes at ten thousand feet but not so much for small engines at ground level. He suggested the racing fuel as well.

I spoke with VP fuels and asked if I should add a stabilizer , they advised it was not needed. They had not been able to make it go bad in storage . Two years should be fine.

 

[tsteahr]

Dogballs, I thought the 100LL av gas was going to save my day. Thought it would have been easier to buy Meth though ! " if you bring a bunch of 5gal cans for your 'sea plane' I'll fix you up !" I was thrilled. Switched everything over and within the week was in trouble. Filled my 1.5" 5hp Honda pump, ran fine , left it full and in 3-4 DAYS the tank was empty. A gasket at the bottom of the tank was eaten away. Then two chainsaws started acting up. I called Sta-Bil (I had added that to the ave gas )and one of their engineers called me back and went into more detail than I would ever need as to why the 100LL was great for planes at ten thousand feet but not so much for small engines at ground level. He suggested the racing fuel as well.

I spoke with VP fuels and asked if I should add a stabilizer , they advised it was not needed. They had not been able to make it go bad in storage . Two years should be fine.

Thanks for the information about not needing stabilizer in the VP fuel. Makes me feel even better about using it. Interesting to note I'm not the only one who thinks aviation fuel is a poor idea in small engines. I appreciate your post. :thumbsup:

 

[MacLawn]

Right. I think I have already posted this link for finding non-ethanol gasoline a couple of times, and two others have posted the link here already:

Ethanol-free gas stations in the U.S. and Canada

You can add/delete stations in your area as they change their ethanol gasolines; sometimes a station stops selling non-ethanol, sometimes stations begin selling non-ethanol.

For me, since I learned of this web site and found several stations in my area, it has become a non-issue. I just don't use ethanol gasoline.

 

[abeal]

Dogballs, I thought the 100LL av gas was going to save my day. Thought it would have been easier to buy Meth though ! " if you bring a bunch of 5gal cans for your 'sea plane' I'll fix you up !" I was thrilled. Switched everything over and within the week was in trouble. Filled my 1.5" 5hp Honda pump, ran fine , left it full and in 3-4 DAYS the tank was empty. A gasket at the bottom of the tank was eaten away. Then two chainsaws started acting up. I called Sta-Bil (I had added that to the ave gas )and one of their engineers called me back and went into more detail than I would ever need as to why the 100LL was great for planes at ten thousand feet but not so much for small engines at ground level. He suggested the racing fuel as well.

I spoke with VP fuels and asked if I should add a stabilizer , they advised it was not needed. They had not been able to make it go bad in storage . Two years should be fine.

Wow...I've been using 100LL for years in a lot of my small equipment and have not had any of those problems. In the 4 strokes with sumps, the lead does seem to contaminate the oil a little more. Recently I've been using the 100LL for "winterizing" engines.

While I have/had a plane, nobody at an airport has asked for a tail number when I come in with a gas cans. You can tell them you're building a plane (experimental/homebuilt - no N number yet assigned) at home and need the gas to test the engine.