Three typical autogas users

The GAfuels Blog is written by two private pilots: Dean Billing, Sisters, Ore., an expert on autogas and ethanol, and Kent Misegades, Cary, N.C., an aerospace engineer, aviation sales rep for U-Fuel, and president of EAA1114.

If you speak with any of the thousands of pilots who have enjoyed the benefits of autogas since the first STCs were approved by the FAA in 1982, you’ll notice their surprise that anyone would doubt that it is an excellent aviation fuel option for many aircraft. The same holds for the growing sector of LSA aircraft, whose engines are typically best run on 91+ AKI octane, ethanol-free, lead-free autogas. In recent months, your bloggers have heard from many of these pilots, dismayed that supplies of ethanol-free fuel are disappearing, and that the FAA appears to be unwilling to preserve their aviation fuel while focusing attention on finding a one-size-fits-all, drop-in replacement for leaded avgas. Following are comments from three of these pilots.

Stanley Edwards, private pilot, Raleigh, N.C: “I’ve used autogas in several partnership aircraft and sole owned aircraft over the years, for instance a 1974 Cessna 172 (650 hs.), 1971 Cessna 182 (1,300 hs.), 1964 Debonair (1,500 hs.), 1969 Cessna 150 (300 hs.) and a 1964 Cessna 172 (200 hs.). The only times I’ve purposely used 100LL has been after overhaul of the 182 engine, overhaul of the Debonair engine, new cylinders on the 150 and when no autogas was available when away from my home base. I have only good things to say about use of autofuel. The engines simply run cleaner. No engine wear or failure has been attributed to autogas use in any of these engines. The only engine problems I have had came with prolonged 100LL usage. With ethanol free now almost impossible to get, I really dread the increased maintenance.”

Bob Ward, president, Nutmeg Soaring Association, Freehold, N.Y: “Our glider club was founded in 1956. We have been using autogas for many years in our towplanes, a Piper Pawnee and an Aviat Husky. My fuel supplier just informed me that he can no longer get ethanol free, and we don’t know what to do. Why isn’t the FAA doing something to keep ethanol out of our fuel? If we have to switch to leaded avgas, our costs will go higher and we’ll lose members. Leaded fuel is also not good for our engines.”

Bob Cushing, owner, Sport Pilot Chicago at Cushing Field, Newark, Ill.: “I loaned the EAA one of my Cessna 172s in the 1980s so they could certify the plane for autogas use. I estimate that my fleet of training aircraft has, over the years, accumulated over 50,000 hours of safe operation running on autogas. For instance, we put 3,000 hours burning autogas in a Lycoming O-235 before an overhaul. The spark plugs stayed clean and we still had good compression at 3,000 hours.”


  1. says

    Dennis – While you may believe that ethanol fuels will be here for years to come, that does not mean that we must be forced to use them. There is NO federal mandatory E10 law and every state mandatory E10 law, all five of them, has exceptions for aviation, marine, antique, classic and recreational vehicles and small engines used in portable tools because they recognize that ethanol blended fuel should not be used in these applications. There is NO requirement in federal or state law that says we must use ethanol blended gasoline, and quite frankly it is dangerous in aviation and marine environments and will eventually lead to deaths in the public safety sector that relies on portable tools. Besides why would you want to put a fuel in your airplane that develops less energy so that your climb rate decreases, your range decreases and you have to fill up more often? The reality is that ethanol blended fuels are only applicable in closed fuel system vehicles that have computer controlled fuel injection systems that can compensate for the extra oxygen. It should not be used in open fuel system vehicles with carbureted engines, which is why mandatory E10 states have exceptions in their laws for those applications.

  2. Douglas says

    You don’t understand one of the problems with ethanol. Ethanol absorbs water. When it has absorbed enough water, it drops out of solution and settles to the bottom of the tank. Now the octane rating of the fuel is lower because the ethanol has been removed, and there is a slug of water/ethanol mix in the bottom of the tank that can freeze or slush up and clog filters or fuel ports at very cold temperatures (such as at high altitude in winter).

    Why add ethanol at all? It causes more problems than it solves. It causes corrosion in my motorcycle carburetors, my lawn mower, snow blower, friends’ boats, etc.. Just allow 91+ octane fuel to be sold without ethanol added and the problem is solved for about 90% of all piston aircraft, Sure seems like a no-brainer to me and many others!

  3. Dennis Reiley says

    I’ve said it before and I’ll say it again, the aviation industry needs to redesign their engines and fuel systems to use ethanol fuels. First they didn’t want to convert from 100LL, now they complain about the lack of ethanol free fuels.

    Stop complaining and start dealing with reality. Ethanol fuels will be here for years to come, they will also be the dominant fuels. You can piss and moan or you can face reality. Because of this refusal to deal with reality aviation fuels will remain high priced. High fuel prices restrict flying hours for general aviation, the last thing anyone wants.

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