A long cross-country on mogas

Thanks go out to GAfuels reader Michael Gallagher of Peoria, Ill., for sending us this story on his recent long cross-country trip in the mogas-burning, Rotax 912ULS-powered RANS S-7S he built himself:

“On June 19th, I loaded up my 2011 Rans S7S with luggage and my 5-year-old son/co-pilot and took off from Peoria, Ill., (KPIA) for Syracuse, N.Y., to spend a week with his grandparents. The tanks were filled with 27.5 gallons of 91 AKI mogas and after a mid-day fuel stop at Wynkoop Airport (6G4) in Ohio for refueling with 100LL we were on our way again. The unfortunate choice of 100LL was due to the lack of any 91 AKI mogas anywhere near my route. After seven hours of very smooth CAVU flight, we arrived in Fulton, N.Y. (KFZY). Carrying three fuel bags from Alaskan Bushwheels made refueling with mogas easy to fly family around upstate New York and to fill the tanks for our return trip home.

Little did I know that the weather patterns would conspire to keep us prisoners for a total of 17 days. Weeks of rain and low IFR persisted until a fateful day in the first week of July; we were sprung from our soggy retreat. The flight home was almost three hours longer due to winds aloft, three stops to check weather and plot our next detour around rain and, of course, fuel.

When weather ahead and no cell signal for weather on my iPad prompted our first stop in Jamestown, N.Y. (KJHW), the route was adjusted for weather, and again in Sebring, Ohio (3G6) with a fuel top off of 100LL. A few dog legs later to avoid rain cells I was about to call it quits for the day when sunshine and great visibility appeared on cue over Marion, Ohio. The final leg home was smooth sailing with a quick refueling stop in Logansport, Ind. (KGGP).

The use of Decalin to help with lead deposits from 100LL helped, but the filthy black appearance of the oil after using several tanks of 100LL prompted an oil change upon our return home.”


  1. Michael Gallagher says

    Keep in mind that MOGAS isn’t one size fits all. My Rotax 912 engine can use 91 octane or higher with 10% ethanol. I have found many of the airports listed on flyunleaded.com only carry 87 octane. Of the total number of airports claiming to have MOGAS, not that many have 91 octane. Take a look at the Google map I made that has just the 91 octane airports.


  2. Rich says

    We have had mogas at KPPO La Porte, IN ever since they did away with 80 Octane.

    PPO is close to the Southern tip of L Michigan.

  3. Dave Hill says

    I appreciate you writing about your experience. I can’t say that I can think of a better title at this moment. I can REALLY appreciate the Mogas issue. Our airport is in the middle of the country and focuses on refueling jets and could care less about Mogas. They’re getting ready to finally install automated system for 100LL. We have a Tecnam P92 Eaglet Light Sport that we do training with and burn through about 25 gallons a week. Our mechanic told me that we need to go to 91 Octane auto fuel so that we don’t have to change the oil on our Rotax engine every 25 hours. It is a good thing I drive a 2008 Cadillac that uses 91 Octane. I’m going to start pumping fuel out of my Cadillac into a couple 7.5 gal gas cans and then use those to re-fuel our plane.

    • Kent Misegades says

      Thanks Dave, keep up the good work debunking the many myths around mogas. Its popularity continues to increase. One day perhaps even the aviation alphabets will realize this and help expand its use.

  4. Dave Hill says

    Great story. I can relate to the 17 day weather delay… BUT come on guys. Article title is totally misleading. You guys are sounding like CNN & Fox News. Title suggested that he flew the x-country using mogas… which would be a very interesting accomplishment.

    • Kent Misegades says

      Dave, the editor changed the headline, which was originally “A long cross country on mogas and Decalin”, to underscore what the hassles for a Rotax engine owner when he is forced to use leaded Avgas. We have spent a great deal of time, on our own nickel, the past three years helping airports get mogas, with no help from the aviation alphabets. While the number of such airports is still small, the trend is upwards. Just got news that the Cambridge, NE airport will start selling mogas in the near future.

      • Douglas says

        2G2 in eastern Ohio has 90 oct mogas.
        According to the Rotax owner website, 2/3 tank of 90 + 1/3 tank of 100LL = at least 92 oct. (Not sure if the 90 is MON or AKI, so it could be higher).

        • Kent Misegades says


          Mogas (gasoline) is always rated by AKI in the US. AKI = (RON + MON) / 2

          Avgas is rated by its MON number.

          The Rotax 912 series requires 91+ AKI, but can be run on 100LL if a lead scavenger like Decalin is used.

          Follow the official documents from Rotax and Lockwood. Be cautious with something claimed by a blog or forum, even if it makes sense. Lockwood folks in Sebring know best, contact Dean Vogel down there and tell him hi from Kent. He taught my son, an A&P & Rotax/LSA Repairman.

          • Dave Hill says

            Hey guys

            Our mechanic just finished Rotax certification with Ronnie Smith, featured in September issue of Kitplanes. Most Rotax engines can run on 87 Octane but the new 912 and 914 need the 91 Octane. The whole fuel thing has been pretty frustrating until I realized you just need to own a car that uses the same gas as your airplane and then it is just a matter of transferring the fuel with a pump and hose. The Flo-Fast guys have got it figured out, http://youtu.be/fzzU30Ig8Zo

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