RobBurson wrote:...... Even if methanol blends turn out to be ok, my complaint is there is not as much power in it. That means you burn more to go the same distance. ...........

Assuming the airplane is OK with methanol/ethanol, I wouldn't mind if it burned a bit more to get somewhere-- I'd be more concerned that maybe it wouldn't quite have the steam to get over the tall trees at the end of the runway.

Eric

I think blueldr is on the right track.

zero.one.victor wrote:I'd be more concerned that maybe it wouldn't quite have the steam to get over the tall trees at the end of the runway.

Is this a noticeable effect? I never thought about the fact that maybe we're generating fewer ponies with 87 mogas. Has anyone here been able to quantify this in any way?

I've been thinking about getting the STC, mainly just because...why not? Less lead, less cost. Although in my case the old bird does sit for periods.

Flat COuntry Pilot,

Where are those STC's for use of ethanol in auto gas for aircraft use? The FAA and the engine manufacturers have specifically prohibited the use of ethanol in av fuels, regardless of their blend.

There is research going on regarding these fuels in aircraft, but it's not there yet.

You can probably get away with it in many simple aircraft. DON'T run the stuff in anything that has fuel bladders, some of which used natural rubber. Some are newer materials, but they are expensive, so do you want to be the tester?

Ethanol is a different product also than ISOPROPYL, which is the only approved fuel additive for moisture other than Prist. Ethanol or Methanol (ie: yellow bottle HEET) is NOT an approved fuel additive. HEET in the red cans is Isopropyl, and legal for moisture prevention in winter. Isopropyl doesn't attack rubber.

I'd be careful with this stuff, and replace rubber parts frequently, like gas cap gaskets, etc. May not seem like a big deal, but I've seen these gaskets turn into jello, probably due to exposure to ethanol. Then water starts finding its way into tanks, etc.

The jury is still out. There is a lot of research going on with this stuff right now, so there'll probably be more "data" soon.

MTV

Mike,

Here is a link to the only STCs that I know exist.

http://www.age85.org/STCs.htm

Take note that this is for 85% aviation grade ethanol, what ever that means. It can be mixed with 100LL at any level desired.

Bill

I wonder how many pilots have burned ethanol blended gas in their plane and to this day don't know it

For now, I will continue to use 100LL and let the powers that be do the experimenting.

Bill

I just read this entire thread. I am just as confused now as I was when I started to read it.

Is it my understanding that our little O-300 engines run better with a lower octane rating, 87 or so, and no lead???

Is it also my understanding that so far there is no ethonal/methonal, or what ever it is actually called, found in Oregon at this time??

This is the only fact that I can find at this time. At my airport AvGas is $3.80, MoGas is $2.55, that is $1.25 per gallon cheaper. Of course they are both going up as I am writing this.

In my airplane, if the fuel burn is consistent with both fuels, a trip to Bend and back would cost me approximately $110.00 with AvGas. It would cost approximately $74.00 with MoGas. That is $36.00 is savings. Now I did a little more figuring of what savings I would have over a year’s time. (The only reason I used Bend is I am going there in two days to pick up a new gun. )

Last year I flew my 170 approximately 170 hours. Now at 8 gallons an hour that is 1360 gallons of AvGas I used. With an average fuel price of $3.80 per gallon that is $5168.00. If I would have used MoGas, with and average cost of 2.55 per gallon, that would be $3468.00. A difference of $1700.00.

But all this comes back to the same questions, will MoGas hurt my airplane, yes I do have the STC. Is it worth the $1700.00 in savings? Do I need to upgrade parts of my fuel system? Will I get carb icing if I use Mogas?? I’ve gotten carb icing with AvGas.

I am so confused!!!! But the approximate $1700.00 in savings looks good as long as the engine keeps running.

zane wrote: ........ I never thought about the fact that maybe we're generating fewer ponies with 87 mogas. ...............

I'm not talking about regular 87 octane car gas, Zane, I ws quoting Rob's post which was in reference to gasohol. I believe there's as much energy in a gallon of 87 octane car gas as in a gallon of 80/87 avgas, which is what our old engines were originally approved for.
Common wisdom: cargas doesn't have as good a shelf life as avgas, so use 100LL if the airplane's not gonna fly regularly. I don't know if I concur, I've left regular car gas in my lawnmower over the winter and 4-5 months later, it seems to run fine. But then again my life doesn't depend on that mower running properly either! I'd go along with the common wisdom in this case. So far, however, my airplane's never sat idle long enough to worry about the gas going bad.

Eric

pif_sonic

ETHANOL is blended with car gas, not methanol.

With an stc for car gas in your plane, you should be ok. But you should not have ethanol in the car gas if your putting it in your airplane.

Bill

MTV, I was thinking this morning and came up with this idea. I've had good luck running 50/50 ethanol gasoline blends in unmodified vehicles( 92 Toyota 4x4 and 95 Ford Aspire) for 5 to 6 years now and making biodiesel from french fry grease and running it in my 30 year old John Deere tractor at a 50/50 blend of No. 2 diesel and biodiesel that John Deere would never approve of. Anyway, you're at Crookston teaching aviation and I got to thinking about the school doing some testing. I would consider paying for a little bladder made by Eagle Fuel Cells in Eagle River WI. The idea would be to make a little cube that would hold a gallon or so and have a quick drain and some sort of way to fill with 10% ethanol auto fuel. I would want you to change out the fuel every 3 months or so. Maybe an aluminum neck and fuel cap could be incorporated. If you and the school would do this it might disprove some common misconceptions and you could see for yourself. If this $4 avgas is the norm, you might as well say GA is doomed. Think about it.
Marty

You might find this interesting also.

BY THE NUMBERS:
- 5,000 - The number of gallons of ethanol that were shipped to Homestead-Miami Speedway for use by IndyCar Series teams this weekend.

- One - The number of plants that produce ethanol for the IndyCar Series. Renova Energy in Torrington, Wyo., is the exclusive supplier.

- 2005 - The year the IndyCar Series first announced plans for use of ethanol, after years of running on methanol.

- 10 - The percentage of ethanol blended with methanol in 2006, to prepare the IndyCar Series to the move to 100 percent fuel-grade ethanol in 2007.

- 22 - The size of an IndyCar Series car fuel tank. Since ethanol is more efficient than methanol, the IndyCar Series has reduced the size of its fuel tanks to 22 gallons this season.

- 6,372 - The number of laps run during the preseason Open Tests using 100 percent fuel-grade ethanol and the new 3.5 liter Honda HI7R V-8 Indy engine with no failures.

I do not think that any bladders were ever made with natural rubber. I do not think that any thing is made from the rubber tree plant anymore. Thought that synthetic rubber replace the natural stuff due to the German U-boats causing all the trouble in the shipping lanes during WWII. Hey MTV, an old boat sailer is supposed to know this stuff.

I have piped a couple of bulk fuel plants and the gaskets we use are a nitrile rubber. Epdm ruber is not compatable. There are an endless varieties of rubber. The rubber that is used in "O" rings in faucets is one thing and the ones used in hydraulic cylinders is somthing else.

In a 180 or 182 with fuel bladers that have been replace in the last ten or more years and a new carb at the last engine overhaul there are no parts that ethanol will work against. I havn't seen a cork gasket since I restord a Modle T Ford in 1962 to 1964. Correct me if I am wrong.



Tim

Wayne, I've been running my 170 on mainly cargas for 9-1/2 years abd about 1500 hours. Had no problems atributable to car gas. Clean plugs, no fouling, no clinkers at inspection time.
I used to run 75% 87 cargas /25% 100LL, as per Petersen Aviation's STC recommendations. Since gas prices started going wild a couple years ago, I run almost all car gas, pour in 5 gallons of 100LL once in a while.
BTW, according to Petersen, the old 80/87 avgas has 1/2 gram of lead per gallon. 100LL has 2, cargas has none. So if you run that 75/25% mix they recommend, you just about duplicate the lead content of the old 80/87. Which is why they recommend it.

Eric

I guess the question on Alcohol in the fuel is what it will do to the fuel system, gaskets etc., and it's effect on combustion.

Both Ethanol and Methanol are corrosive with METOH being more so.

METOH is seldom seen in gasoline any longer due to the lower energy content ( 45% of Gasoline and only 75% of Ethanol ) and it produces toxic byproducts during combustion.

Ethanol is listed as having a higher Octane rating ( less knock ) than gasoline but less energy.

The vapor pressure of Ethanol is slightly higher than gasoline in summer so there may be a slightly higher tendency for vapor locks.

To sum it up. WHO THE HELL KNOW??

Tim,
I agree with you 100%.
Everyone around here started to panic when they started blending ethanol with our gas swearing it was going to eat hoses, valves, gaskets, etc. but it hasn't made a bit of a difference. I bet in Missouri a person couldn't find gasoline that hasn't been cut to some extent with ethanol if they tried. The only thing I would worry about is shelf life. If your not going to fly in a year you may get some stale gas.

This topic really begs for more speculation and conjecture

The Petersen Aviation pages seems to be a good start for getting information on the topic.

Gasoline blended with ethanol is corrosive and attacks fuel systems, not only the rubber components but aluminum too. If you cannot find gasoline that you are certain is ethanol free then you must revert to using avgas until non ethanol automotive gasoline can be obtained.

I'd like to see the evidence that shows the deterioration of rubber and aluminum components. What do my old '72 Volvo and '89 Nissan pickup have in their fuel systems that is so advanced and resistance to corrosion? Having run thousands of gallons of auto fuel through them (in the last 10 years too), I haven't encountered any damaged fuel system components.

Did Petersen have to do the tests regarding the corrosive effects of ethanol, or did he just have to abide by some pre-cooked evidence and regulations mandated by the FAA?

Boy. isn't it ironic that Peterson, the leader in auto fuel stc's is based in Nebraska. The leading state for ethanol production.

If you're the least bit concerned about the power output of your engine on mogas, please remember that the way you determine power output is by close observation of your tachometer on a full throttle static runup. That will always tell you if the engine is performing up to specification.
The TCDS of your airplane will specify what this should be. These specs will apply at all geographic elevations. More manifold pressure at sea level, but less air resistance on the prop at higher elevations will even things out.
Octane rarting has no effect on power development unless the engine gets into the detonation range. The lead in higher octane fuels is only used to delay the onset of detonation. (And it doesen't lube the valves either.)

Rob,

Did you get your gas tax question or answered?

Bill

Still trying to negotiate through Alaska's website about Mogas tax rebates up here. I know it is available for boats...