Fuel

[hilltop170]

I recently heard a good way to test for the presence of any ethanol in mogas is to put some gas in a clear container and add one drop of food color, the kind from the grocery store that is water based. If the drop goes to the bottom, no alcohol. If the drop diffuses in the gas, ethanol is present.

I haven't done it yet but it's worth a try if it works.

[bsdunek]

What you do not want is ethanol in the gas. And not just because it is not legal. It is because, in my first hand personal experience you will cause more problems for yourself from water the ethanol attracts and the rust water will start in the tanks. There is also a possibility the ethanol will eat into some rubber in the fuel system.


Bruce, I have aluminum tanks, hence no rust. I do agree it attracts more water. Jeez I am going to butt out of this gas deal. I guess if you can't afford avgas then there are probably a lot more serious things you cannot afford that may be more critical.

It really is not that much more expensive and especially based on the number of hours we typically fly

You may not get "rust" from aluminum tanks, but if you see what ethanol and water in the fuel does to aluminum, you won't want it in your plane. It becomes very corrosive, attacking aluminum with a vengeance. Don't know about yours, but my 170 also has aluminum fuel lines, and aluminum castings for the fuel valve and carburetor. You might get by in a dry climate, but not here in Michigan. There's just too much risk, IMHO, to even think about using any fuel with ethanol.

[bagarre]

It's going to be interesting to see what they come up with to replace 100LL.

http://www.deltahawkengines.com/

[marathonrunner]

170C wrote:
It's going to be interesting to see what they come up with to replace 100LL.


http://www.deltahawkengines.com/

I am just guessing that will be one very expensive STC to acquire. Look at the cost already associated with the IO 360 Continental and it has an STC. To get one from ground up is going to be very expensive. I am not sure the number of 170's would justify it if every single one bought the STC.

[bagarre]

Yeah. I don't think diesel is going to be a viable option in a 170 until gasoline is gone and cars run on batteries.
But I'm glad some people are looking into it.

[marathonrunner]

We all new in the late 70's that a suitable alternative to leaded fuels needed to be found. Now that the was it "Friends of the Earth" petitioned the EPA in like 2007? to remove lead it has finally surfaced to the front of the stove from the back burner. This has all the usual groups, AOPA, and others on the warpath to "hey you can't ban lead in our gas". Where were all these guys in the late 70's when we were warned of what was going to happen? This is not new news.

Lead was and is of course necessary until a suitable replacement can be found. New engines for old aircraft requiring STC's are the most expensive route to go. Finding a suitable fuel is hopefully a better route A fairly informative and humorous brief history of not only the guy who invented so to speak TEL but also CFC's which are far more damaging to the atmosphere is found in Bill Bryson's book "A Short History of Nearly Everything"

Thomas Midgley jr. and the gas companies back then coined the term Ethyl for the additive to make it sound "friendly" while they knew the dangers and what it was doing to their own workers.

Midgley was eventually killed by his own invention but, I won't give away the details. Look it up.

[Thart739@gmail.com]

I love the great feedback. Thanks to everyone who chimed in. I think as much as I fly and can afford to fly I will just use 100 ll for now. I figured you guys have probably heard this question a thousand times..

[spduffee]

I recently heard a good way to test for the presence of any ethanol in mogas is to put some gas in a clear container and add one drop of food color, the kind from the grocery store that is water based. If the drop goes to the bottom, no alcohol. If the drop diffuses in the gas, ethanol is present.

I haven't done it yet but it's worth a try if it works.

I took a glass jar, filled it 2/3 full of my newly found pure gas, then drew a line with a black marker at that level. I then added water to top it off. If Ethanol would have been in the gas, the water would have mixed with it and the gas portion would have been lower than the line. I still have that sample from over 1 year ago - no change. Same thing, but different.

[Bruce Fenstermacher]

I took a glass jar, filled it 2/3 full of my newly found pure gas, then drew a line with a black marker at that level. I then added water to top it off. If Ethanol would have been in the gas, the water would have mixed with it and the gas portion would have been lower than the line. I still have that sample from over 1 year ago - no change. Same thing, but different.

Actually if you have to shake the mixture to blend it then and then let the "water" settle out. If it appears there is more water than when you started, it is because the ethanol molecules have clung to the water molecules and they look the same so it all looks like water or more water.

It does not matter how much gas you test or how much water is used in the test, any convenient amount. I use about a cup of gas and about 1/4 cup of water. Shake then let sit. Takes about 5 minutes for enough water or water and ethanol to settle out and see if it looks like more water than you started with. If you are more precise you could actually figure out how much ethanol is in the fuel. But I don't care. Any ethanol and it's not going in my airplane.

[170C]

Way back when they started putting ethanol in automobile gasoline (must have been in the mid to late 1990's) I burned quite a bit of mogas (enough to get a sufficient road tax refund from the state of TX to buy just over 100 gallons each year for quite a number of yrs) I made an ethanol "kit" out of a glass rain gauge. I marked it as mentioned above so I would fill it to that mark with fuel, then add water up to another mark, shake it vigorously with a cork in the open end. I would wait a few minutes to see if the sample indicated any ethanol. I could drain way more gas from the pump hose than needed for my test before deciding whether or not to purchase my 100 or so gallons. Fortunately I never did find any and my "kit" was small enough to carry in my plane when going somewhere that had mogas. As I recall at that time I was told that ethanol was usually added only to super unleaded mogas, but I was never confident enough of that to not test the regular mogas first.

[ginbug92b]

IT IS NOT JUST ABOUT PRICE!!!! It's about choking on 4X the lead in the fuel than 80 OCT avgas.

[GAHorn]

IT IS NOT JUST ABOUT PRICE!!!! It's about choking on 4X the lead in the fuel than 80 OCT avgas.

The ASTM specification allows....up to four times....the lead. That does not equate to actually containing that much.
According to most tech articles I've read, 100LL typically contains about half the allowance specified (which should equate to about twice as much as the old 80/87.)

Lack of proper delivery and storage systems, unacceptable and unpredictable recipies, shortened shelf-life, and serious damage to expensive airplane fuel components...are all valid reasons to avoid mogas.

Has anyone noticed that modern automobiles are using stainless steel and plastic fuel-line components?
Ever wonder WHY?
Ethanol-laced fuels are electrically-conductive. (Ordinary, quality gasoline is not.) One problem of fuel systems is the variety of components which, when electrically-connected, can promote electrolysis.....and corrosion.
Using plastic not only reduces the availability of corrosion-capable components...but also insulates metallic-components from each-other...further helping to isolate differing materials. This helps keep automobile fuel system components passive as far as corrosion goes. (My new trucks' entire fuel system, from cap to throttle-body is plastic, including the tank.)
Despite what anecdotes are used to describe the Army's un-ending supply of dispensable men-and-equipment....
Despite the mogas STC's that under closely-controlled experiments demonstrate short-term compatibility.....
Airplanes that carry the mortal people I care about aren't designed to use auto/mo-gas. Even if I could afford to replace the damaged parts and equipment...I can't replace the cargo...or adequately explain to them why I thought it was worth their risk. That's why I don't use it.

This is answer No. 80. (Easy to remember since it matches the octane in which we're interested.)

It amazes me the numbers of people who will spend $9/qt for purple motor oil and buy trick-filters for their cars and then throw mogas in their airplanes.

[WSHIII]

Well this is my first post here, guess I might as well stir the pot and get it over with.

I recently purchased a '52 170 with a 180 hp conversion and just joined up.

This has been discussed ad nauseam on every website I've ever hung around.......And while I've seen and heard all kinds of well meaning anecdotal evidence on why you shouldn't use Mogas, I've yet to see any real, objective, scientific data to support that notion. None! Never! If anyone has some, I'd really like to see it. Seriously. And I gotta believe if there was even a hint of any problem from using it, the FAA would be all over it. That's what they live for, it helps to justify their existence.

FWIW, I've used Ethanol free Mogas now almost exclusively in 3 different aircraft for nearly 4,000 hours, without any problem whatsoever. No issues of icing at altitude, no vapor lock, no corrosion, no damaged seals, no gummed up carburetors,.........Nothing!

Occasionally one or another airplane sits unused for several months or so, with only Mogas left in the tanks, with no ill effects. Chevron reports their fuel is stable for two years, well, maybe but, I'm not suggesting anyone test their claims either. I've gone 6 months before without any problems. And to be fair I did add some fresh fuel to what was still left in the tanks. Maybe a 1/3 tank of fresh fuel. But several months is/has really been a non-issue.

I usually save somewhere around a $1 a gallon here locally, give or take, which translates into several thousand dollars a year in savings for me. Several thousand! Year after year. Or, another way of looking at it. The money saved by using Mogas will more than likely pay for my overhaul when the time comes. I can't afford not too!

I'm not saying you have to use it.........I'm just saying..........it works for me.

[blueldr]

WSHIII,
Amen!
In addition to what you mention above, I have used alcohol laced fuel since they started requiring it in California after the demise of the MTBE additive some years ago. Never had a problem with it either.
I was never able to find a source of alcohol free fuel locally. Never had any kind of a problem with either the stock C-145/O-300 or the Continental IO-360 engines in the C-170B.

[Bruce Fenstermacher]

Well this is my first post here, guess I might as well stir the pot and get it over with.

I'm not saying you have to use it.........I'm just saying..........it works for me.

Welcome. And as you have noted MOGAS and it's use has been discussed ad nauseum and this site is no exception. With the widespread use of ethanol and virtually no mogas without it the pot is not stirred as often as it was and there are only three guys left who will take the time to make the same comments we've made hundreds of times. Two of us kind of moderate the forum and we feel compeled to respond when the third posts. You've just heard from the third, I'm the second, number one should be around any moment.

I'm happy you can get MOGAS without ethanol. Wish I could.

Now as you have set the tone on your introduction lets open another can of worms and see where you stand and get it out of the way. And that is one of legality and flying a legal and airworthy aircraft. You just bought a '52 with a 180 conversion. You can not legally use MOGAS in this airplane. What are you going to do?