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Mogas or Avgas?

Probably no subject has ever generated a more impressive amount of hearsay and old wives tales than the subject of all the terrible things ethanol admixed fuel will do to your aircraft.

In 2008, EASA (European Aviation Safety Authority) had the University of Aachen in Germany do a study on the safety implications of biofuels in aviation: https://easa.europa.eu/essi/egast/wp-content/uploads/2011/03/Final_Report_EASA.2008-6-light1.pdf


Now, for the first time, scientists have made a scientifically valid study of the effects the use of 5% admixture may have on your flying. The net result: If you don't store your gas for too long, don't fly above 10,000', don't let your gas heat up to above 140 F and keep your jerricans clean, it is no big deal.

It is a very interesting study, particularly if you have an interest in chemistry and possess the stamina to read the whole hog. ;-)
 
180Marty said:
Maybe should read up on that statement since that's not right.



I know of a big Continental that has aluminum fuel lines feeding it for over 8 years and they don't leak yet. This person seals up the vent between flights and trys to add fresh fuel just before flying. Also, has a teflon fuel line to the carburetor.
Click to expand...

I was wrong, here they say 2/3 the energy of gasoline, In a gallon of gas with 10% éthanol you have a little bit less BTU
http://zfacts.com/p/436.html
 
BES said:
Probably no subject has ever generated a more impressive amount of hearsay and old wives tales than the subject of all the terrible things ethanol admixed fuel will do to your aircraft.

In 2008, EASA (European Aviation Safety Authority) had the University of Aachen in Germany do a study on the safety implications of biofuels in aviation: https://easa.europa.eu/essi/egast/wp-content/uploads/2011/03/Final_Report_EASA.2008-6-light1.pdf


Now, for the first time, scientists have made a scientifically valid study of the effects the use of 5% admixture may have on your flying. The net result: If you don't store your gas for too long, don't fly above 10,000', don't let your gas heat up to above 140 F and keep your jerricans clean, it is no big deal.

It is a very interesting study, particularly if you have an interest in chemistry and possess the stamina to read the whole hog. ;-)
Click to expand...

Yes, but I can tell you matter of factly that if you let your plane sit during a rainy week and go to Fla on vacation, and return that the untreated ethanol gas will suck water like a sponge. And when you try to run it you will only get about 1400rpm. I drained some of the week old gas into a glass jar and it was milky looking. Drained tank and replaced with fresh ethanol treated gas and ran great. If you going to run it untreated burn it up quick and don't let it sit more then a couple days. Keep some Startron in the baggage in case you need it.

Glenn
 
Um - if this 95 mogas does not stop your Mercedes, what in it would stop an aircraft? Yes - leave it sit for a month or so, and you will have problems. Operate it like your car, and you will have the same fuel issues as you do with your car - usually none.

I too use Teflon fuel lines in the Cub, and 100LL exclusively in the Super Dec. because I have no idea what is inside those lines, or what kind of sealer is in the tanks. Airplanes have crashed because of sloshed tanks and MTBE.

I heard it takes more energy to produce a gallon of ethanol than you get out of it.
 
If you are concerned about water in your ethanol adulterated fuel, there is a simple fix. Get yourself a tank with a conical bottom like they use in making biodiesel. Agitate the fuel and whatever water is involved will mix with the alcohol and settle to the bottom. You can then either draw from top or decant the water off of the bottom.

Trouble is that when you buy gasoline containing ethanol, the octane rating depends on that ethanol. Alcohol raises the octane rating of gasoline. When you remove the alcohol, you lower the octane rating. If you start out with 93 octane mogas and remove the alcohol you will lower the octane rating. How much? I am not sure as they didn't have such mixtures when I was a practicing Chemical Engineer.

Eddie
 
TurboBeaver said:
Got to reerect this thread with the simple question............. I realize lots of folks use high test car gas that is ethanol free by itself and lots of different blends mixed with 100LL, but I just had an old friend from Dillingham , tell me he and a bunch of the cub guys out their are running
Reg car gas WITH ethanol in their engines??? Can some of the guys that are running it please comment on how this is working out?
Click to expand...

Alaska is ethanol free. Unless they are getting their mogas from Seattle.
 
I heard it takes more energy to produce a gallon of ethanol than you get out of it.
Click to expand...
Maybe about 20 years ago. I'm in three different ethanol plants and I think they are around 22,000 BTU's per 76,000 btu gallon of ethanol. Then they send 33% of the bushel of corn that came into the plant back out as a higher quality processed feed for livestock. Here is a newsletter from a plant that I'm not in but this one just switched from coal fired to natural and is also hooked up with DuPont to make cellulosic ethanol. Click on the winter newsletter for some interesting reading. Things just keep getting more efficient. One plant I'm in is just installing corn grinders that are used in the dogfood industry because they make the particles a more uniform size and even that is a big deal----the list goes on and on.

http://www.lincolnwayenergy.com/newsletter.htm
 
remove the alcohol you will lower the octane rating. How much? I am not sure as they didn't have such mixtures when I was a practicing Chemical Engineer.
Click to expand...
10% ethanol raises the octane about 2.5 points. The 84 sub octane that comes from the refinery becomes 87 when blended and in Minnesota they take 91 pure and it becomes 93 with 10% eth.
 
I had one landing last year at 9200', and had a pretty good pop/ backfire when I shutdown. A half hour later I fired it (Rotax) back up and all was normal so I gave it no further thought. I had E-10 that day, other landings at similar heights on pure gas, no backfire. No big deal, didn't seem to hurt anything.
 
bob turner said:
U - if this 95 mogas does not stop your Mercedes, what in it would stop an aircraft? Yes - leave it sit for a month or so, and you will have problems. Operate it like your car, and you will have the same fuel issues as you do with your car - usually none.

.
Click to expand...

Bob, remember the song. " it never rains in southern California "

Glenn
 
180Marty said:
Maybe 20 years ago. I'm in three different ethanol plants and I think they are around 22,000 BTU's per 76,000 btu gallon of ethanol. Then they send 33% of the bushel of corn that came into the plant back out as a higher quality processed feed for livestock. Here is a newsletter from a plant that I'm not in but this one just switched from coal fired to natural and is also hooked up with DuPont to make cellulosic ethanol. Click on the winter newsletter for some interesting reading. Things just keep getting more efficient. One plant I'm in is just installing corn grinders that are used in the dogfood industry because they make the particles a more uniform size and even that is a big deal----the list goes on and on.

http://www.lincolnwayenergy.com/newsletter.htm
Click to expand...

Thats because all the ethanol refineries are 100% subsidized

Glenn
 
Thats because all the ethanol refineries are 100% subsidized
Click to expand...
The only thing that could be construed as a subsidy is the Renewable Fuel Standard, saying to the oil companies "you will use X amount of biofuel per year". Lots of talk of doing away with that. NO SUBSIDY MONEY. But, oil companies LOVE making 84 octane gas. One of the ethanol plant guys told me that he thinks what oil companies really want is to own the ethanol plant too so they can get back to monopoly status. With the RFS, nobody said it had to be used as E10, it could be used as E30 or E85 and there wouldn't be enough ethanol to blend into the nation's gasoline----there'd be E0 everywhere. I've been using E30 to E50 in unmodified vehicles since 2001, vehicles as old as 1992 with no problems but officially that doesn't work. I've done some "firsts" with farming too and have heard, you can make it work but I know it wouldn't work for me.

PS Glen, how many vents on the fuel system on you plane?????
 
Last edited:
180Marty said:
PS Glen, how many vents on the fuel system on you plane?????
Click to expand...

Marty it's the same plane we PMed about a few years ago. Only one vent in the cap, I know last time you told me to seal the vent when it's parked. That would take care of it when parked. But if you have looked at some of my pictures you know most of the time I'm not flying over that nice flat corn ground like you have in Iowa. And I also fly in the same terrain north of me when it's raining cats and dogs and 1400rpm ain't going to get me home. I'm still helping your corn fuel investment though, burn the ethanol gas just treat it first with Startron. I want my BTUs to be as waterproof as possible

Glenn
 
Gotta ask this question, by changing out the fuel line out to teflon down at gascolator, that solves that problem
But on most of airplanes we are flying, what about the rubber lines where we come off the fuel
Tanks, seems like unless you changed them as well , same thing will happen to them?
 
http://www.eaglefuelcells.com/ga/new_faa.html

Once installed, the cell is externally durable, internally impermeable, resistant to ozone damage and shrinkage and is compatible with all aviation and pump gas fuels, oils, and most corrosive fluids.
Click to expand...

I don't know about others, but my Cessna doesn't have any rubber lines between the bladders and the gascolator. I think Eagle uses nitrile rubber for their bladders.
 
TurboBeaver said:
Gotta ask this question, by changing out the fuel line out to teflon down at gascolator, that solves that problem
But on most of airplanes we are flying, what about the rubber lines where we come off the fuel
Tanks, seems like unless you changed them as well , same thing will happen to them?
Click to expand...

Gascolator is the worst one, most have a twist and a bend begging to collapse. Most of the other ones are just to join 2 tubes together.

Glenn
 
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