Finding Airports that sell 91 Octane Mogas?

J

Jamaica Scott

Filing Flight Plan
Joined
Aug 1, 2020
Messages
6
Display Name
Display name:
Jamaica Scott
Hello All,
Is there any resource to find airports In the USA that offer 91 or higher octane mogas? My aircraft has a Rotax 912iS engine and needs high octane mogas. When I look on ForeFlight or Garmin Pilot for airports selling mogas, then call them, it is 87 octane. Only place I know of is Sebring FL that sells it. I hear so much about Swift Fuels 94 UL product, but very few airports sell it. Auto fuel went unleaded in the 70s. It’s about time!
I do use 100LL but the lead causes me to do oil changes twice as often.
Jamaica Scott
Negril Jamaica
 
You could try air nav.
 
I did try that site. But I found that was not kept up to date.
 
frfly172 said:
You could try air nav.
Click to expand...
The problem is not just finding mogas, it is that Rotax engines require premium fuel. Minimum of 91 octane.
With the thousands of Rotax powered aircraft, one would think that we could lobby the database keepers to differentiate between Mogas and premium Mogas.
 
Ethanol up to 10% is not a problem for Rotax. It’s just the octane. It needs to be 91 or higher. It seems most airports selling mogas only offer the least expensive 87 octane.
 
I've been flying behind a Rotax 912 for 7 years. I use 91 octane E-10 at my home field and fill up with 100LL on cross country flights. And I don't worry about it because you simply will not find 91 octane available at airports. Just ease your mind and eliminate that option from your planning. You'll be fine. Plus, a 912 oil change is simple. I mean, we're talking 3 quarts and a filter.
 
Cluemeister said:
Many rotax fliers haul mogas to the airport in 5 gallon cans.
Click to expand...

My engine isn't a Rotax but it requires at least 93 octane (AKI) and I refuse to use ethanol in my plane while trying to avoid too much lead.

So ... I can find E-Free 90 octane at a nearby station to mix with 100LL to get the required octane for my engine. When flying cross country I just use the 100LL and Decalin (for experimental only) and that helps with the lead. I change oil at 25-30 hours.

Easy enough to calculate the proper octane for your aircraft if you decide to mix fuel but this makes is easier: http://wallaceracing.com/octane-mix-calc.php
 
Daleandee said:
My engine isn't a Rotax but it requires at least 93 octane (AKI) and I refuse to use ethanol in my plane while trying to avoid too much lead.

So ... I can find E-Free 90 octane at a nearby station to mix with 100LL to get the required octane for my engine. When flying cross country I just use the 100LL and Decalin (for experimental only) and that helps with the lead. I change oil at 25-30 hours.

Easy enough to calculate the proper octane for your aircraft if you decide to mix fuel but this makes is easier: http://wallaceracing.com/octane-mix-calc.php
Click to expand...
Be careful. The octane scales of auto gas and aviation fuels are not the same. The old 80 octane aviation fuel is about the same formula as the old 87 octane regular leaded auto gas.
 
Octane requirements specified by Rotax are European standard, where they use RON. US octane ratings are different ((R+M)/2); 93 RON is equivalent to US 89, so standard US 91 octane is fine for your Rotax.
 
Dana said:
Octane requirements specified by Rotax are European standard, where they use RON. US octane ratings are different ((R+M)/2); 93 RON is equivalent to US 89, so standard US 91 octane is fine for your Rotax.
Click to expand...

I did not know that. My nearest gas station has ethanol-free 91 octane, which I use pretty much exclusively in my ROTAX-powered Sky Arrow when local. It’s nice to know I have a cushion. I do not sweat using 100LL when necessary, and do carry Decalin on cross countries in case it really helps*.

I’ve used Airnav to find airports with 91+ mogas. There are a few I can use enroute, or at least there were last I checked. One in SC if I’m headed SE, one in NC (Mountain Empire) when headed north. Flying to AZ I found a Light Sport dealer in North Little Rock that could top me off. Sometimes I can find fellow Light Sport owners who are willing to meet me with appropriate mogas. Or sometimes just friends with gas cans if the airport is amenable to fueling from cans on the ramp - apparently not all are.

Along those lines, if anyone finds themselves near Knoxville, TN and is comfortable with a 1,700’ grass strip, I can usually provide up to about 22 gals of E0 mogas from cans - I keep 3 5gal and 3 2.5gal cans in a box outside my hangar and could easily shuttle to the station 3 miles away for more if needed. Just give me a shout ahead of time so I can be sure the cans are full.


*Anecdotally, I have a friend that runs a Light Sport flight school in Lock Haven, PA. He only has 100LL available, and runs his ROTAX’s exclusively on that, with no issues other than more frequent oil changes. He stopped using Decalin - he felt that while it seemed to work holding lead in suspension, he attributed some recurring exhaust cracks to that lead ending up deposited in the exhaust. Not conclusive in any way, but he’s an engineer and a smart guy, so I value his opinion.
 
Last edited:
Jamaica Scott said:
The problem is not just finding mogas, it is that Rotax engines require premium fuel. Minimum of 91 octane.
With the thousands of Rotax powered aircraft, one would think that we could lobby the database keepers to differentiate between Mogas and premium Mogas.
Click to expand...

Jamaica Scott said:
Ethanol up to 10% is not a problem for Rotax. It’s just the octane. It needs to be 91 or higher. It seems most airports selling mogas only offer the least expensive 87 octane.
Click to expand...

With the summer months and temperatures, be careful with MOGAS and ethanol. You really want ethanol free MOGAS if you're going to use it exclusively. There have be plenty of cases of vapor lock (including those aircraft with fuel return lines) that may be attributed to ethanol blended fuels.

I fly on 100LL and just do more frequent oil changes since it gets plenty warm in Southern California. Meanwhile I know someone in Florida who flies to a nearby airport for ethanol free MOGAS and has not had a problem.
 
FastEddieB said:
I did not know that. My nearest gas station has ethanol-free 91 octane, which I use pretty much exclusively in my ROTAX-powered Sky Arrow when local. It’s nice to know I have a cushion. I do not sweat using 100LL when necessary, and do carry Decalin on cross countries in case it really helps*.

I’ve used Airnav to find airports with 91+ mogas. There are a few I can use enroute, or at least there were last I checked. One in SC if I’m headed SE, one in NC (Mountain Empire) when headed north. Flying to AZ I found a Light Sport dealer in North Little Rock that could top me off. Sometimes I can find fellow Light Sport owners who are willing to meet me with appropriate mogas. Or sometimes just friends with gas cans if the airport is amenable to fueling from cans on the ramp - apparently not all are.

Along those lines, if anyone finds themselves near Knoxville, TN and is comfortable with a 1,700’ grass strip, I can usually provide up to about 22 gals of E0 mogas from cans - I keep 3 5gal and 3 2.5gal cans in a box outside my hangar and could easily shuttle to the station 3 miles away for more if needed. Just give me a shout ahead of time so I can be sure the cans are full.


*Anecdotally, I have a friend that runs a Light Sport flight school in Lock Haven, PA. He only has 100LL available, and runs his ROTAX’s exclusively on that, with no issues other than more frequent oil changes. He stopped using Decalin - he felt that while it seemed to work holding lead in suspension, he attributed some recurring exhaust cracks to that lead ending up deposited in the exhaust. Not conclusive in any way, but he’s an engineer and a smart guy, so I value his opinion.
Click to expand...

What airport in SC sells 91 Mogas?
 
Indeed, BNL is the only one in SC that I can find. It may actually be the closest to me here (north of CLT). The guys who burn Mogas here trailer it in. They're investigating buying it in bulk but I don't know if they've gotten anywhere on that project.
 
I’m fortunate to have a Stewart Ice Cream Store, near my airport, that carry’s 91 octane non ethanol fuel, at decent prices. I only use 100LL on cross country’s and mix in some in the winter, as the 100LL shelf life is longer.
 
Jamaica Scott said:
Ethanol up to 10% is not a problem for Rotax. It’s just the octane. It needs to be 91 or higher. It seems most airports selling mogas only offer the least expensive 87 octane.
Click to expand...

Yes the Ethanol is not bad for the Rotax but it's VERY BAD for most of the gaskets and sealers that seal gas tanks on a plane. Tanks that are riveted into a wing are then sealed with something that does not like Ethanol. I know, I had a problem with this in my plane. It's ridiculous that ethanol is used at all. They actually use gasoline to make it, making it more expensive and it doesn't help the environment like they claim. It's all political. In Illinois we are forced to use that garbage because our Democratic Government pushes it on us for corn production. The more corn production the more taxes collected...You have to be stupid not to understand how this works. These are pay offs. It's a political party buying favors instead of caring for it's citizens. I fly to Wisconsin to buy ethanol free MOGAS. When I store it for a longer period of time, I add Stabil. Rotax is not the only aviation motor out there that can use MOGAS. In my opinion if a small field want to increase it's business, get it. People will fly in for it.
 
Shouldn't Rotax Service Point airports all have 91 Octane? They are somewhat common. Also, any marina with a boat ramp or dry dock or floating dinghy dock without pylons should be able to fuel a seaplane.
 
Last edited:
If you can figure out a way to land at Buc-ee's, a lot of them have 93 octane E0.

Hell, as big as they are they could build a runway.
 
Jamaica Scott said:
Ethanol up to 10% is not a problem for Rotax. It’s just the octane. It needs to be 91 or higher. It seems most airports selling mogas only offer the least expensive 87 octane.
Click to expand...
Ethanol may be ok for the Rotax engine (even though it's not), but it reeks havoc on fuel lines, fuel tank sealer. Ethanol can be safely used if it's used quickly after filling. It breaks down, attracts water and destroys seals. And you under no circumstance want it to sit idly in your tank for a month or more without burning it out of your plane.
 
This thread is hilarious with all the old wives tales about ethanol.

You do know that the FAA flew a 172 with 100% ethanol for a decade and never had a problem?

But some guy on the i the internet says and a drop in your tanks is gonna kill you.

Pure comedy it is.
 
pfarber said:
You do know that the FAA flew a 172 with 100% ethanol for a decade and never had a problem?
Click to expand...
If no problems how come the FAA issued guidance not to use ethanol in aircraft? Plus the fact the popular Mogas STCs all prohibit the use of ethanol as well. So do you have something to present that states otherwise? Seems the only comedy here are your posts.:rolleyes:
https://rgl.faa.gov/Regulatory_and_...f958b6a22286257259006d6dab/$FILE/CE-07-06.pdf
https://www.autofuelstc.com/stc_specs.phtml
 
pfarber said:
This thread is hilarious with all the old wives tales about ethanol.

You do know that the FAA flew a 172 with 100% ethanol for a decade and never had a problem?

But some guy on the i the internet says and a drop in your tanks is gonna kill you.

Pure comedy it is.
Click to expand...
Personal (or close to) experiences.
I run pump fuel in my Rotax - most likely E-10 (don't check). If it's been sitting for more than a couple months (yes, it happens) I try to top off at least one tank with fresh fuel. Sometimes. But I've never had a problem with old gas, (SAE) fuel lines, or anything else over the last 13 years. Well, OK, I have had the aluminum tanks crack at the welds, but I'm pretty darn sure that was from oil canning and not E-10
A buddy ran auto fuel in his Kitfox - when he built it he wanted to do it "right" and used some "aircraft grade" rubber fuel lines (sorry, don't remember the exact spec.). Engine failure on takeoff - found the hoses had swelled internally reducing the fuel flow.
 
Bell206 said:
If no problems how come the FAA issued guidance not to use ethanol in aircraft? Plus the fact the popular Mogas STCs all prohibit the use of ethanol as well.
Click to expand...
Poor quality materials used by the OEMs for fuel lines / gaskets / etc. don''t play well with E-10. You need automotive stuff. See previous post.
 
BlueDream said:
Ethanol may be ok for the Rotax engine (even though it's not), but it reeks havoc on fuel lines, fuel tank sealer. Ethanol can be safely used if it's used quickly after filling. It breaks down, attracts water and destroys seals. And you under no circumstance want it to sit idly in your tank for a month or more without burning it out of your plane.
Click to expand...


Agree^^^^^^^^^^^^^
 
Capt. Geoffrey Thorpe said:
Poor quality materials used by the OEMs for fuel lines / gaskets / etc. don''t play well with E-10. You need automotive stuff. See previous post.
Click to expand...
FYI: incompatible materials are just one issue with using E fuels in legacy aircraft. Increased icing, vapor lock, and storage separation round off the top 4 E-fuel issues found by a number of in-depth studies over the years. Some of those studies even used a Rotax engine to quantify certain findings as well has comparing various mixtures (E_0, E-5, E-10, E-15) across a number of parameters. In the end the collective result of these studies points to GA fleet wide safety issues ranging from nuisance-level to grave danger level. Some of the older studies are in the public domain if you care to read them.
 
pfarber said:
This thread is hilarious with all the old wives tales about ethanol.

You do know that the FAA flew a 172 with 100% ethanol for a decade and never had a problem?
Click to expand...

I'm sure they went though the engine and fuel system and replaced anything incompatible with ethanol. Not something you'd want to try with a stock 172. Most likely it flew more frequently than the average personally owned airplane, too, lessening the moisture issues.

The problems with ethanol in fuel are well documented. They're not all insurmountable, but they can't be ignored.
 
Utah-Jay said:
I can tell you that UT9 is not listed on that website but ONLY sells MOGAS. I suspect there are more
Click to expand...
Hi all. I am the curator of this site (flyunleaded.com), and UT9 is not listed because we were told you have to be a member of their club to buy MOGAS there. If you have information to the contrary, please share, and I'll get it listed right away. The site has been recently updated with a lot of new entries, and some removed. It took many (volunteer) man hours to do this and is the most up-to-date information out there. We've also made it easier to make updates, but we rely on pilots to make reports as the FAA data and others are simply not reliable. So please, anyone with info on a MOGAS or UL94 airport that sells to the public, please go onto the site and submit a report. We promise to do our very best to keep it up to date. Also, please note that we need to verify with the respective airport or FBO manager before we can list a field. And also note that MOGAS availability changes quite frequently. Facilities sometimes can't refill their tanks, or the price is too high, or something else happens. Unfortunately, it is not yet as reliable as 100LL. Which is why we have this site, so there is something out there as a resource.
 
Last edited:
You must log in or register to reply here.
Back
Top