[Rick of Austin]

With the uncertainty of avgas it seems prudent to ensure we can burn mogas, even with alcohol, for the long term.
Years ago I bought an EX-360 from superior and they claimed it was okay to burn auto fuel.
Now that we have gasahol is there anything we need to do or incorporate as we build up an O-360?
So far all we know is to;
1. use a carb with metal float
2. use teflon lined stainless braided hoses.
3. compression ratio???

How about the mechanical pump, is the diaphragm at risk? Anything else such as special valve guides?
Thanks

 

[breister]

Yes, absolutely confirm the material in the fuel pump.

Every material in the fuel system needs to be checked to insure that the material will withstand both gasoline and alcohol. Plastics, rubbers, and any other form of flexible tube or gasket are suspect.

 

[lostpilot28]

I think your biggest risk is vapor-lock. There are a lot smarter guys on here than me that can speak to that, however. I ran auto fuel (91 octane) for the first time last weekend, but it was a mix of 10 gallons auto and 5 gallons Avgas. I made sure to buy the gas from a gas-station listed on the "non ethanol" website, but I'm not sure whether it was ethanol-free or not.

Back when I had a Pulsar XP with a Rotax, I ran auto fuel exclusively. I never had any problems...at sea level or at altitude. I'm quite certain that most of that fuel was 10% Ethanol, too, considering I lived in Southern California.

I'm curious about anything else that may be a potential problem, too. I have a short stretch of stainless steel braided racing fuel hose from Pegasus Auto Racing...their website says that it's good for "most racing fuels", so I don't know if it's OK long term with ethanol.

Other than vapor lock, water, and rubber fuel lines, I can't think of anything else that could be a problem.

 

[frankh]

Yes

Been running pretty much gashol only for 4 years or so.

I use an AFP FI and dispensed with the mechanical fuel pump. I have two electric pimps.

Water in the fuel appears to be an non issue but I have only flown at 15.5k in the dead of winter so far..

Do a search under my name for a description of my system. there are a number of ways to do it and some do not like my design. But vapour lock and material compatibility are non issues for me.

I run 8.5:1 and almost always lean of peak.

Frank

 

[Ron Lee]

Don't do anything to preclude the use of 100LL. I will formally predict here and now that 100LL will be with us at least a decade and possibly far longer.

 

[lostpilot28]

Been running pretty much gashol only for 4 years or so.

I use an AFP FI and dispensed with the mechanical fuel pump. I have two electric pimps.

Water in the fuel appears to be an non issue but I have only flown at 15.5k in the dead of winter so far..

Do a search under my name for a description of my system. there are a number of ways to do it and some do not like my design. But vapour lock and material compatibility are non issues for me.

I run 8.5:1 and almost always lean of peak.

Frank

Hey Frank, what are the benefits of having your fuel pumps in the wing-root area vs. the firewall? Also, why get rid of the mechanical pump? Wouldn't it make a nice backup if the electric pumps stopped (or vice versa)?

 

[frankh]

well...

The very best place to pump from is the source..Sucking on fuel is a bad thing.so is warming the fuel as it boils more easily..So i would never put a pump on a firewall or above the bottom of the tank..

hence my pumps are in the coldest lowest place possible..i.e next to the fuel tanks. If I were doing it again I could probably talk myself into putting them on the floor of the cockpit.

The mechanical pump is in the almost very worse place possible..Oh and it won't stand up to ethanol as far as I could find out.

So why keep it?

its easy to design electrical redundancy..ask any IFR pilot..Keeping the fuel pump makes about as much sense as keeping the vacuum pump..You'll never know when it will rollover and try to kill you. I feel the same about the mechanical pump.

Frank

 

[airguy]

hence my pumps are in the coldest lowest place possible..i.e next to the fuel tanks. If I were doing it again I could probably talk myself into putting them on the floor of the cockpit.

Funny you should say that - I came to the same conclusion, and that's where I ended up putting mine. I used a pair of the boost pumps, had to put the filters on the bulkhead, and fabbed an elongated cover for the whole mess.

 

[TSwezey]

Flew 150 hours and never had a vapor lock issue. Water would usually blow through causing a small burp once in awhile. Scared me the first time.

 

[rvaitor87]

auto fuel

I have an 0-320 B2B. And I tried the auto fuel route, and my plugs would foul by the time I reached the end of the runway, about a 5 minute journey.
Would the age of the motor be a factor here? The motor is at least 20 years old. When I run avgas, there are no problems. I don't know what the price of avgas is elsewhere, but here in Fla. (BOW) it is $4.00/gal. auto gas is $3.00/gal.

 

[Ron Lee]

Mike, that seems contrary to what I would expect. Do you lean the mixture aggressively for taxi?

 

[aerhed]

Personally, I prefer that my engine has the ability to keep running without any electrical system avaialable. So, for me, I will always install a mechanical pump. Same for battery fired ignitions, even though they work better than mags. I suppose I could come up with a dedicated power supply for ignition that makes me happy if I had to. It's pretty easy to rebuild a mechanical pump with ethanol-proof guts. Kits are less than $50.

 

[cln1owner]

Personally, I prefer that my engine has the ability to keep running without any electrical system avaialable. So, for me, I will always install a mechanical pump. Same for battery fired ignitions, even though they work better than mags. I suppose I could come up with a dedicated power supply for ignition that makes me happy if I had to. It's pretty easy to rebuild a mechanical pump with ethanol-proof guts. Kits are less than $50.

Source for these ethanol-proof guts?

 

[RV7ator]

Back to the original question...

If you can run pure gas, there's really nothing to change or harden in an engine of recent vintage - which in aviation years is several decades. Lead once cushioned the exhaust seats from the hammering they endured when they were made from much softer material. If you're running 8.5:1 or less, you don't need lead for its primary (and really only) purpose, detonation suppression. 91 mogas will suffice.

Switching between 100LL and mogas should be unnoticeable in operation with two exceptions... plug fouling and vapor lock. Mogas won't foul if 100LL won't in your engine, but not always the other way around. YMMV. Vapor lock is an iffy thing, and not something to be concerned about with the engine running and fuel flowing. Once in a while, I'll do a hot start on a hot day and get a bit of chuffing and chugging with mogas until it's all liquid in the system.

The real risk in mogas is encountering ethanol. Oh, your engine will run on it but you will not have the same BTUs/volume. My experiments yielded a 4 mph cruise reduction with E10 compared to 100LL without adjusting mixture. Hardening the fuel system against ethanol from tank to spark plug will require diligent investigation of each and every soft material along the way for ethanol resistance. A few easy-to-overlook examples: tank drains, gascolators, o-ring seals on Lyc pump fittings. Regarding Lyc fuel pumps, the diaphragm is definitely susceptible to ethanol deterioration. There's some noise about Vantage changing materials, but their pumps are also used on certified ships and such a change is a regulatory nightmare and the experimental market is too thin to economically develop its own part. The Brazil operators simply regularly change out pumps. If the poster above has specifics on substitutions, tell us.

In sum, just pour in ethanol-free mogas; you may need operational adjustments (like starting). And every opportunity, remind your elected imbecile in Washington that even with the triple protections of subsidies, tariffs, and mandated use, ethanol is an economic and green failure.

John Siebold

 

[aerhed]

Here's one of them. A Google will get you a bunch of them.
http://www.classicpreservation.com/fuelpumpkits.html

 

[RVbySDI]

If you can run pure gas, there's really nothing to change or harden in an engine of recent vintage - which in aviation years is several decades. Lead once cushioned the exhaust seats from the hammering they endured when they were made from much softer material. If you're running 8.5:1 or less, you don't need lead for its primary (and really only) purpose, detonation suppression. 91 mogas will suffice.

Switching between 100LL and mogas should be unnoticeable in operation with two exceptions... plug fouling and vapor lock. Mogas won't foul if 100LL won't in your engine, but not always the other way around. YMMV. Vapor lock is an iffy thing, and not something to be concerned about with the engine running and fuel flowing. Once in a while, I'll do a hot start on a hot day and get a bit of chuffing and chugging with mogas until it's all liquid in the system.

The real risk in mogas is encountering ethanol. Oh, your engine will run on it but you will not have the same BTUs/volume. My experiments yielded a 4 mph cruise reduction with E10 compared to 100LL without adjusting mixture. Hardening the fuel system against ethanol from tank to spark plug will require diligent investigation of each and every soft material along the way for ethanol resistance. A few easy-to-overlook examples: tank drains, gascolators, o-ring seals on Lyc pump fittings. Regarding Lyc fuel pumps, the diaphragm is definitely susceptible to ethanol deterioration. There's some noise about Vantage changing materials, but their pumps are also used on certified ships and such a change is a regulatory nightmare and the experimental market is too thin to economically develop its own part. The Brazil operators simply regularly change out pumps. If the poster above has specifics on substitutions, tell us.

In sum, just pour in ethanol-free mogas; you may need operational adjustments (like starting). And every opportunity, remind your elected imbecile in Washington that even with the triple protections of subsidies, tariffs, and mandated use, ethanol is an economic and green failure.

John Siebold

John, you make some very good points about ethanol use. They are all very valid. There really is not a monster hiding in the ethanol fuel that will come up and bite your engine. At least in regards to the technical aspect associated with burning ethanol in an internal combustion engine.

The statements about vapor lock and water being more of an issue with ethanol is just fear mongering. It seems that everyone from politicians to the local TV Weatherman use fear to try to convince us we should do something or other differently than what we are doing now, or that we should accept what they are telling us.

The real truth of the matter is ethanol is a fuel like all other fuels. It has its pros and its cons. It will do some things better than gasoline (or 100LL) and some things worse. In my opinion the "things that are worse" are all related to the economics of using ethanol. The "subsidies, tariffs, and mandated use. . ." are all economic negatives concerning ethanol. When one pays the same, or in some instances, more for ethanol laced fuel, consumers lose. Not only are you getting less performance in the form of slower speeds as John mentioned, one also is losing out on the distance traveled on that fuel compared to the same amount of non-ethanol fuel. Why would anyone pay the same price for fuel that gets them 20% less in useful motion (i.e. shorter distance traveled per gallon) or less performance. This is the part that I balk against.

 

[rvaitor87]

Mike, that seems contrary to what I would expect. Do you lean the mixture aggressively for taxi?

I do lean somewhat, but not alot. there should not really be any difference in the fuels that I can see. The only one is lead Vs. unleaded, as far as the flying, I never saw any difference. I am considering a 50/50 mixture to see how that works.

 

[frankh]

Wondering

I do lean somewhat, but not alot. there should not really be any difference in the fuels that I can see. The only one is lead Vs. unleaded, as far as the flying, I never saw any difference. I am considering a 50/50 mixture to see how that works.

If there is a density/viscosity thing going on between mogas and 100LL in a carbed engine.

I.e would mogas be pulled through the carb jets more easily than 100LL..seems unlikely but if you are certain about the symptoms its the only explanation I can come up with.

As for leaning...yes lean like crazy for taxiing!..until it is almost too weak to run at all. You won't do it any harm and I bet that will solve your plug fouling.

Taxi out and taxi back this way without the cowling top and check your plugs. I bet your problem will have dissappeared.

Frank

 

[frankh]

a bit of an assumption I think

Personally, I prefer that my engine has the ability to keep running without any electrical system avaialable. So, for me, I will always install a mechanical pump. Same for battery fired ignitions, even though they work better than mags. I suppose I could come up with a dedicated power supply for ignition that makes me happy if I had to. It's pretty easy to rebuild a mechanical pump with ethanol-proof guts. Kits are less than $50.

Certainly nothing wrong with your approach..But if you have an (I)O540 on takeoff on a hot day i would assume you basically have a single electric pump.

I,e you can't rely on your machanical pump to pump anything due to vapour lock.

VL to me is a bigger deal than running two electric pumps with a properly designed electrical system..But each to his own.

Frank

 

[aerhed]

VL to me is a bigger deal than running two electric pumps with a properly designed electrical system..But each to his own.

I do acknowledge yer point. It's just that it's what I'm used to & it makes me comfortable. I lost complete electrical one night and forgot my flashlight. I had to rev up the old radium gage lettering every few minutes with my cigarette lighter. Then I had to wait around until someone keyed the runway lights so I could piggyback in. Having an engine that never burped sure helped keep the anxiety level down.

 

[Sig600]

The statements about vapor lock and water being more of an issue with ethanol is just fear mongering. It seems that everyone from politicians to the local TV Weatherman use fear to try to convince us we should do something or other differently than what we are doing now, or that we should accept what they are telling us.

Alcohol binds to water like a fat kid to a cupcake, and also has a very low boiling point (i.e. Vapor lock). 174F if memory serves.

 

[frazitl]

Dave, thanks but

I checked out the link, and the guy is obviously supporting old autos. Any guidance on a model number or car fitment that would work for our lycodinomotors???

 

[David-aviator]

Alcohol binds to water like a fat kid to a cupcake, and also has a very low boiling point (i.e. Vapor lock). 174F if memory serves.

I am no a fan of ethanol in fuel, I'd using mogas right now if I could buy it conveniently without ethanol. But there are some myths about it and water, and vapor lock.

I bought a gallon of E85 and tested it for vapor pressure along side of some 100LL. The E85 came in at 62 on the Hodge test kit from Petersen, about the same as the 100LL. Vapor lock is no worse or better than with 100LL. Water and ethanol is no big deal. There are about 100 million autos out there and there is no evidence water in fuel is a problem and for sure there is some water in mogas now and then. As far as boiling point is concerned, 174F would be great. I am certain 100LL boils at a lot less than that. I am of the opinion that 110F is critical for 100LL.

I don't like ethanol but it is not because of water or its vapor pressure limits, its because it will destroy the seals in the mechanical fuel pump.

I've been making inquiries about making the Lycoming fuel pump impervious to ethanol and here is one response I got -

David,
We are currently testing rubber materials that will be compatible with
ethanol.
Testing has been very promising. The actual FAA approval process will take
some time to complete.

Victor Harris
Aero Accessories, Inc.

There is hope.

 

[Ted Johns]

Alcohol binds to water like a fat kid to a cupcake, and also has a very low boiling point (i.e. Vapor lock). 174F if memory serves.

Ethanol lowers the vapor pressure of mogas, it doesn't raise it. In cold countries where they use E85, they increase the percentage of gasoline in the winter to ease starting. The lighter fractions of gasoline have a much higher vapor pressure than ethanol.

Now, the Reid vapor pressure of mogas is not as strictly regulated as avgas, so it could be higher, but not because of the ethanol.

 

[SHIPCHIEF]

Building for all fuels

I'm building an RV-8.
I intend it to be tolerant of all gasoline.
Right now I've been flying the Autogas STC'd Cessna on fuel from a local CFN fuel farm, (Don Small Fuel Farm, Auburn WA) which is ethanol free, and $3.19.9 per gallon. Local Avgas is $5.85 a gallon.
It adds up fast.
My RV-8 project has automotive fuel injection components, all are tolerant of ethanol blended fuel.
My engine will have different power output depending on the fuel, I suppose the low octane mogas will require a lower manifold pressure than high octane mogas or 100LL. I'm not sure yet how I'll establish the limits and enter the data in my POH.
My son Peter just got a Bellanca 14-19-3A flying. It looks like a Viking, but is the older 260. It's got an IO-470F. That sucker drinks 100LL. Sure is fast tho-
I think the fuel cost in dollars per mile is about the same as the Cessna 182 on car gas. rv's are fast like that too, so maybe 100LL isn't such a large cost of the over-all operation. I just like the idea of using all available gasoline types safely...just in case.

 

[Sig600]

Ethanol lowers the vapor pressure of mogas, it doesn't raise it. In cold countries where they use E85, they increase the percentage of gasoline in the winter to ease starting. The lighter fractions of gasoline have a much higher vapor pressure than ethanol.

Now, the Reid vapor pressure of mogas is not as strictly regulated as avgas, so it could be higher, but not because of the ethanol.

That was kind of my point, ethanol is not that resilient to the wide variety of operating extremes that even RV's can impart. From static atmospheric pressure, to temperature variations over just a few minutes.

 

[Ted Johns]

That was kind of my point, ethanol is not that resilient to the wide variety of operating extremes that even RV's can impart. From static atmospheric pressure, to temperature variations over just a few minutes.

Your point is incorrect. Ethanol is more tolerant of temperature variations.

 

[RVbySDI]

Alcohol binds to water like a fat kid to a cupcake, and also has a very low boiling point (i.e. Vapor lock). 174F if memory serves.

Well, this is really kind of my point in saying much of the talk about ethanol is Fear Mongering. Perpetuating misinformation in the hope that our society, government, manufacturers, et. al. will somehow change their mind about using ethanol is not an effective way to argue against ethanol use. I agree with you and many here on this post about using ethanol. I just don't agree with you about the arguments being used to support your position against the use of ethanol.

As others have mentioned already, the vapor lock issue is not really any more or less of a problem than 100LL or Mogas. The water issue is not relevant at all in the argument either. In fact, the auto industry has actually used alcohol for decades to REMOVE water from fuel. That alcohol (and alcohol/water mixture) was not then somehow physically removed from the fuel tank. It was simply burned with the rest of the fuel as it passed through the engine.

I have posted this document (http://www.epa.gov/OMS/regs/fuels/rfg/waterphs.pdf) several times on numerous other threads that discussed the use of ethanol. It shows in some detail how the ethanol removes water from a fuel mixture. Spend some time studying the research and you will see that the scientific research does not support the notion that alcohol/water bonding is a serious problem with ethanol laced fuel. When you think about it, why would a substance that, for decades, was seen as a good substance to use for the elimination of water from our fuel tanks, has now suddenly become a bad thing to put in our fuel tanks just because we now think of this substance as a fuel source for our vehicles?

Look at ALL of the facts about using ethanol and you will find the serious problems associated with using ethanol as a fuel is economical in nature and not technical.

Live Long and Prosper!

 

[John Clark]

"Dry Gas"

<snip> In fact, the auto industry has actually used alcohol for decades to REMOVE water from fuel. That alcohol (and alcohol/water mixture) was not then somehow physically removed from the fuel tank. It was simply burned with the rest of the fuel as it passed through the engine.

Nothing new here, the "Magic Cure" is 100% ethanol in a handy bottle, first marketed in 1943.

http://drygas.com/html/gas_line_antifreeze.html

I agree with Steve on this issue, there has been a lot of misinformation tossed around to fight the ethanol movement. The best argument against ethanol in fuel is economic, not technical.

John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA

 

[frankh]

Almost

Nothing new here, the "Magic Cure" is 100% ethanol in a handy bottle, first marketed in 1943.

http://drygas.com/html/gas_line_antifreeze.html

I agree with Steve on this issue, there has been a lot of misinformation tossed around to fight the ethanol movement. The best argument against ethanol in fuel is economic, not technical.

John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA

The other argument is environmental..I.e appears to be at best a zero net benefit while syphoning more money out of our pockets for the privelage.

Frank

 

[RVbySDI]

The other argument is environmental..I.e appears to be at best a zero net benefit while syphoning more money out of our pockets for the privelage.

Frank

actually I was referring to arguments against using ethanol should be economic in nature. The environmental card is strictly coming from the supporters of ethanol use as a fuel.

I might add, your statement further supports my notion that the basis for arguments against ethanol should be economically driven. Why pay a premium price for something that has a marginal environmental benefit (some would even argue it has little to no environmental benefit). If we truly wish to decrease the environmental impact of the fuels we use in our world, we should be pricing this "environmentally friendly" fuel at a big enough discount below the existing fuel price(s) so that everyone will be eager to change over their fuel use to the newer fuel.

 

[Sig600]

Well, this is really kind of my point in saying much of the talk about ethanol is Fear Mongering. Perpetuating misinformation in the hope that our society, government, manufacturers, et. al. will somehow change their mind about using ethanol is not an effective way to argue against ethanol use. I agree with you and many here on this post about using ethanol. I just don't agree with you about the arguments being used to support your position against the use of ethanol.

As others have mentioned already, the vapor lock issue is not really any more or less of a problem than 100LL or Mogas. The water issue is not relevant at all in the argument either. In fact, the auto industry has actually used alcohol for decades to REMOVE water from fuel. That alcohol (and alcohol/water mixture) was not then somehow physically removed from the fuel tank. It was simply burned with the rest of the fuel as it passed through the engine.

I have posted this document (http://www.epa.gov/OMS/regs/fuels/rfg/waterphs.pdf) several times on numerous other threads that discussed the use of ethanol. It shows in some detail how the ethanol removes water from a fuel mixture. Spend some time studying the research and you will see that the scientific research does not support the notion that alcohol/water bonding is a serious problem with ethanol laced fuel. When you think about it, why would a substance that, for decades, was seen as a good substance to use for the elimination of water from our fuel tanks, has now suddenly become a bad thing to put in our fuel tanks just because we now think of this substance as a fuel source for our vehicles?

Look at ALL of the facts about using ethanol and you will find the serious problems associated with using ethanol as a fuel is economical in nature and not technical.

Live Long and Prosper!

Look at the source... the EPA. So we're in agreement then that ethanol is stupid and a waste of money. Reasons varying...

If we truly wish to decrease the environmental impact of the fuels we use in our world, we should be pricing this "environmentally friendly" fuel at a big enough discount below the existing fuel price(s) so that everyone will be eager to change over their fuel use to the newer fuel.

Now you're thinking like a socialist!!! It's still a diminishing return. It takes more energy to produce than it yields, ultimatley doomed to failure. Until the perpetual motion machiene is invented, there will NEVER be a truely renewable energy source. Solar is the closest we've gotten, but still isnt' economical. If you want to minimize your "enviromental impact" then stop flying. Period dot. And stop using electricity too, gotta burn coal to produce most of that in the US.

I feel an overwhelming need to go start a tire fire!

 

[RVbySDI]

Look at the source... the EPA. So we're in agreement then that ethanol is stupid and a waste of money. Reasons varying...

Yes indeed. We are in agreement about the fact that the use of ethanol is not a good thing today. However, I am not in agreement with your statement that it is "stupid" to use ethanol.

I do believe it is a waste of money at its current prices but if it were at least 50% cheaper than regular 100% gasoline then I would absolutely use it every chance I could get. It is a clean burning fuel that has many benefits to the environment and to the performance of an internal combustion engine. Indeed, if it had serious detrimental qualities that decreased performance, top fuel dragsters and other racing vehicles would not be using various alcohol concoctions as fuels in order to increase their performance on the race track.

And, now that I have severely hijacked this thread (unintentional as it is). I voice my apologies to the thread's author. Ethanol and auto fuel, it seems, are destined to be linked for the foreseeable future. This is why I posted my statements on your thread. However, I have taken much to much space with my posts on this topic that rightly belong elsewhere. I will take any future statements to other threads that are more appropriate for this subject.

 

[airguy]

Yes indeed. We are in agreement about the fact that the use of ethanol is not a good thing today. However, I am not in agreement with your statement that it is "stupid" to use ethanol.

I do believe it is a waste of money at its current prices but if it were at least 50% cheaper than regular 100% gasoline then I would absolutely use it every chance I could get.

I believe the orginal point of the thread had to do with burning E10 vs 100LL in our aircraft engines - and this IS economically feasible at the current cost differential. I agree with you that ethanol in general and E10 in particular don't make much sense from a basic Internal Combustion Engine fuel perspective - but running E10 in my aircraft is more economical than running 100LL, even though it has lower energy density and I'll burn more of it per mile flown. The price differential is enough to make it worthwile. When I stick the nozzle in the tank, the only thing I'm really concerned about is miles per dollar, not miles per gallon.

It is a clean burning fuel that has many benefits to the environment and to the performance of an internal combustion engine. Indeed, if it had serious detrimental qualities that decreased performance, top fuel dragsters and other racing vehicles would not be using various alcohol concoctions as fuels in order to increase their performance on the race track.

Non-sequitir. Those guys throw away literally thousands of dollars for a 5-6 second run, a little bit of corrosion or environmental damage is not even an asterisk on their attention budget. If they could figure out a way to shave a hundred milliseconds off a quarter-mile run by dispersing plutonium dust over a third-world country, they would be all over it in a heartbeat. It's not that effciency isn't a prime consideration for those guys - it's that efficiency isn't ANY consideration. If they could get a fuel (any fuel) that would give them 5% less energy per gallon than they are currently using, but they could cram 5.1% more of it into the cylinder on every stroke, they would own the company producing it right now today. They only reason they don't use high explosives as a fuel is because it is too troublesome to meter it into the cylinders and light it off reliably. Likewise, if all I was interested in was raw power, speed, and acceleration, I would be flying something that used Jet-A through an afterburner big enough to stand in.

 

[Garage Guy]

... the only reason we are forced to use alcohol is due to the farm lobbyists and extremist environmentalists

In your report, I'm wondering which environmentalists are you citing that support corn ethanol subsidies? The Sierra Club for example opposes them http://www.sierraclub.org/sierra/200701/decoder.asp.

Big agribusiness support for the subsidies, on the other hand... yes, that's easy to find.

--Paul