Lycoming's View: Automobile Fuels For Aviation

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For decades, general aviation has been operating and designed around a single fuel – 100LL. Now environmental and economic pressures are driving the search for an unleaded alternative. Lycoming firmly believes that an equivalent performance unleaded aviation grade replacement for 100LL is the best total solution for our industry overall. We also know that using automotive blends in aviation is possible for certain engine models if you put the correct controls in place on the fuel. Lycoming's consistent objective is to give our customers as many fuel choices as possible while still maintaining airworthiness.

In the following three guest blogs, Lycoming specifically addresses the topic of automotive fuels for aviation, including our approval to operate certain Lycoming O- and IO-360 engines using an automotive specification fuel. Lycoming strongly recommends a thorough review of the latest revision to Lycoming Service Instruction 1070, "Specified Fuels," which is available online at Lycoming.com.

Lycoming is well aware that other aviation equipment manufacturers have allowed "pump gas," in some cases with ethanol. In the details they provide warnings and cautions addressing some of the issues we raise in these articles, leaving it to the operator to assess risk in using a fuel where they do not know the core properties other than octane. We do not agree with that approach.

Two terms are used repeatedly throughout this series: "pump gas" and "mogas." "Pump gas" refers specifically to fuel that conforms to the ASTM D4814 or Euronorm 228 specifications for automotive fuel and is available for retail purchase at automobile filling stations. "Mogas" refers specifically to fuel that also conforms to the ASTM D4814 or Euronorm 228 specifications, but controlled and labeled differently such that it is "fit-for-purpose" for aviation.


Part 1

The bottom line is that it's possible to make automotive gasoline "fit-for-purpose" for aviation. However, in doing so, you deviate from "pump gas" and end up creating a low-octane unleaded aviation fuel from automotive gasoline blend stock – "mogas." Why do we need to have fuels "fit-for-purpose" for aviation? You achieve Airworthiness by Design, not by luck. Using "pump gas" from the corner gas station is achieving airworthiness by luck.

At EAA AirVenture 2008, Lycoming Engines presented one of its most information-packed press conferences of the last five years. New products, new services, new initiatives – including one that stated Lycoming would seek unleaded automotive gasoline approval for its standard-compression parallel valve O-360 and IO-360 engines.

Automotive gasoline. The ultimate solution for inexpensive, readily available fuel for aviation. The easy answer to replacing leaded avgas for 70 percent of the existing fleet. Since 2008, we've received a lot of questions about when the approval was going to be ready. One would think we would have shouted it from the rooftops when available. Last summer we published an update to our "Approved Fuels" Service Instruction 1070. Yes, Lycoming approved automotive gasoline – "mogas" – on several 360 engine models – and we did not splash the news out in a press release.

There are several reasons Lycoming refrained from the "end zone dance":

  1. We firmly believe that the much bigger issue is making certain we identify and bring to market unleaded aviation grade replacements for 100LL – a solution that would serve the entire fleet
  2. Our "mogas" approval was for the engine only. In order to be legally used in certificated aircraft, the aircraft must also be approved via TC or STC for utilization of automotive gasoline.
  3. The automotive gasoline Lycoming approved controls specifically four parameters to values required to maintain airworthiness of the engine without mechanical modifications or operational limitations. These parameters are also controlled for ground transportation vehicles but in different form.
  4. We did not approve "pump gas." People cannot think that they can simply drive down to the local gas station and purchase automotive gasoline that is known to provide the same level of airworthiness as aviation gasoline.

Before we move further into the subject of automotive gasoline's potential place in aviation, let's repeat why Lycoming believes our existing fleet needs an unleaded replacement to 100LL avgas. First and foremost, the "workhorse" aircraft that drive our industry's economics are mostly designed around 100LL- octane capability. If the "workhorse" demand goes away, we will all suffer higher costs and reduced FBO service levels. Second and no less important, octane capability is just one element of avgas. Not all aircraft and engines need 100 MON octane. However, it's the parameters beyond octane that enable us to achieve airworthiness for the specified operating envelopes of the aircraft we fly today. Third, the fleet that we fly today – both workhorse and recreational - is about fifty 50 times larger than annual new aircraft production and is based on technology designed around avgas properties. We cannot abandon the existing fleet.

The words written might be controversial to some, but let's leave this as Lycoming's opinion and return to the discussion about automotive gasoline – "mogas" and "pump gas." Broadly speaking, both of these are fuels conform to ASTM Specification D4814 or Euronorm Specification EN228. These fuels are designed for ground vehicles and controlled to ensure proper startability, driveability, seasonal emissions control and of course, performance. As ground transport fuels, they are highly influenced by environmental regulations (EPA). They are not subject to aviation regulations (FAA).

The specifications change on an almost yearly basis in response to changing environmental regulations and political mandates such as ethanol inclusion. What is made available to the market for retail consumption is "pump gas" which is NOT "fit-for-purpose" for aviation precisely because it is controlled for ground transportation purposes. So how did Lycoming, self-admittedly one of the most conservative engine companies in the world, approve "mogas" and what exactly did we approve?

Lycoming approved "mogas" by controlling automotive gasoline properties differently than what is done for ground transport vehicle "pump gas." The specifics:

  • 93 AKI for detonation margin (hot day OAT and 500F cylinder heads).
  • Vapor pressure Class A-4 to prevent vapor lock.
  • No ethanol and maximum 1% oxygenates.
  • ASTM D4814 Revision 09b and EN228 Revision 2008:E.

That's pretty specific stuff and only one of those values is listed on the filling station pump. The first three parameters are what fuel wholesalers control when ordering pump gas." In order to get to aviation "fit-for-purpose," Lycoming controlled those same parameters – differently – and locked in the fuel specification revision to avoid a moving target.

Long story short: This isn't your corner market "pump gas." It is automotive-specification fuel with carefully controlled characteristics that help re-purpose it from a ground mission in automobile fuel systems – "pump gas" – to a flight mission in aircraft fuel systems – "mogas." It can be done – but you need to sweat the details. The other detail to sweat is that Lycoming's approval is for the engine only, not the airframe. TCs and STCs are still needed to be legal on certificated aircraft.

In the next articles, we will explain in more detail the controls we placed on "pump gas," why we decided to approve an automotive gasoline on some of our engines, and why Airworthiness by Design should be everyone's first consideration.

Comments (70)

I have been using non-ethanol "pump gas" in aircraft since 1984, and have over 2,000 mogas hours in a Cherokee 140, Bonanza, and Debonair.

Locking into the highest required fuel to cover all aircraft results in the highest cost. Operations at my home field, a tower controlled reliever in a major metro area, are down 50% since 2000. Increases in fuel costs will be the end of personal GA.

Pump gas gives the lower end of GA an option to bypass the cost of unneeded octane, and bypass the high fuel price markup at airports. My personal experience over 27 years suggests that pump gas works just fine.

Posted by: Dan MacDonald | August 8, 2011 8:42 AM    Report this comment

Since it seems that the market is now destroying the cost effectivness and availability of 100LL in the long term. How can those people who need the octane home brew 100LL? By this I mean mixing TEL with "Mogas". Is TEL available to buy? Can I horde it before the evironmental NAZI's take it away?

Posted by: Brad Vaught | August 8, 2011 9:42 AM    Report this comment

Thank you Michael.

I have tried to explain for years that what you call "pump gas" is not reliable to be used in the demanding aviation environment.

But alas, even with your excellent explanation of the differences between "pump gas" and "mogas", the very next two posts on this blog seem to indicate that it is still (perhaps deliberately) not understood. Maybe you need to be a bit clearer and call it “Aviation Grade Automobile Fuel” or "Automobile-Fuel-Derived Aviation Fuel".

There are enough pilots looking to save money that are willing to overlook the fine print on your S.I. 1070 and their STCs that perhaps we need to make it crystal clear.

It’s a shame that we already have at least 2 unleaded options for our airplanes, 91/96UL AVGAS and aviation specification MOGAS but neither is available...

Posted by: Kris Larson | August 8, 2011 11:15 AM    Report this comment

Kent,

Your lack of the use of paragraphs to add definition to different thoughts make your post mostly unreadable.

This is a shame, as you usually have good facts to present.

Posted by: Edd Weninger | August 8, 2011 2:19 PM    Report this comment

Thank you Lycoming for confirming what thousands of autogas users have known for three decades: when quality autogas is used according to the STCs and TCs provided by aircraft manufacturers, it is an excellent fuel that saves its users money and contributes zero lead emissions to the atmosphere.

On "pump" gas - a quick survey of the web site pure-gas shows that 93 octane ethanol-free is widely available at the retail level, meaning it's available at terminals from where airports should ideally obtain their fuel. I agree that the corner gas station can be risky, although there is really little evidence that this is the case provided the fuel is indeed ethanol-free and meets the users minimum octane requirements. 100LL and Jet-A are also not immune to quality issues, stability, contamination and mis-fueling.

Terrminals can, and should, provide autogas buyers with a detailed chemical analysis of the autogas purchased to confirm it meets aviation needs; in most cases it will. I do not agree that we need fewer choices however; a one-size-fits-all solution always results in higher costs, in this case the vast majority of aircraft owners who do not need 100 MON subsidizing the minority who do. More choices are better: autogas, 100LL, 100UL, Jet-A, 94UL, deisel; let the free market decide the mix, not bureaucrats and K Street lobbyists

Kent Misegades (Reposted by Paul Bertorelli 4:50 p.m.)

Posted by: Paul Bertorelli | August 8, 2011 3:50 PM    Report this comment

Kent and Edd, I reposted the above to make it easier to read. Edd, yours is a good reminder for everyone. Don't forget the carriage return and use as many 1500-character bins as you like.

Posted by: Paul Bertorelli | August 8, 2011 3:53 PM    Report this comment

Also, please note that commenting in some of the blogs is turned off due to spamming. The people who are doing this haven't yet realized their pointless linking gets stripped out of the posts.

They will eventuallu figure it out and cease and desist. I'll try to clean these up and repost the comments. Sorry for the nuisance.

Posted by: Paul Bertorelli | August 8, 2011 4:15 PM    Report this comment

I've burned auto fuel from reputable, high volume gas stations in my STC- approved aircraft for over 30 years with no problems. I have tested every source of each purchase for ethanol prior to pumping since the advent of ethanol use in auto fuel. I have burned thousands of gallons with no problems with either the aircraft or engines. I have had significant problems with 100LL, (namely water) over the same period. Of course, it doesn't take much of a problem to be significant...

Posted by: George Rodrigues | August 8, 2011 10:45 PM    Report this comment

I must take issue with Michael Krafts statement that using pump gas is achieving airworthiness not by design but by luck. The STC's were not developed through luck. Detonation and endurance testing was required in order to develop the STC's in the first place, as well as flight testing for airframe STC's which make the engine STC's worthwhile. In certificated airplanes engine approval by itself is, without airframe approval, largely irrelevant.

Auto fuel specifications are indeed designed for ground vehicles, which is why testing was done to approve airplanes to use it. Yes these specifications change frequently. If they changed to the point of creating adverse circumstances then Mr. Kraft's point would be well taken, but with one exception (ethanol) they have changed only for the better, making autogas (without ethanol) more like avgas than it ever was.

I welcome Lycomings revised stance on the use of autogas in general. It's especially refreshing given the repeated attempts by Lycoming throughout the 1980's to discredit auto fuel STC's. However, what Lycoming has actually done is approve a fuel that virtually no one in the US can find and I don't think I'm alone in wondering what the point was.

Posted by: Todd L. Petersen | August 8, 2011 11:44 PM    Report this comment

I assume that the manufacturers of automobile racing gasoline (e.g. Sunoco) have been consulted in this process, correct? What specifications do the high-end unleaded non-ethanol racing gasolines, e.g. Sunoco 260 GTX, not meet and how hard would it be for the manufacturers of those fuels to modify their blends?

sPh

Posted by: Steven Healey | August 9, 2011 9:10 AM    Report this comment

"what Lycoming has actually done is approve a fuel that virtually no one in the US can find and I don't think I'm alone in wondering what the point was."

Sales and marketing. Obviously there were no technical reasons...

Posted by: Mark Fraser | August 9, 2011 9:19 AM    Report this comment

Here is repost from the AVGAS at AirVenture Blog:

Here is the problem with Mogas.

Mogas formulation is allowed to regulated at pretty much every level of government from the Federal, State and even local level. As a result, it currently is all but impossible to obtain ethanol free Mogas. To assure availability of “aviation” Mogas, every single government regulator at every level will need to agree. That’s never going to happen.

All things aviation are regulated solely at the Federal level. This includes Avgas. The FAA has no authority to stipulate the formulation of automobile fuel, only aviation fuel.

The “specialness” of Avgas goes far beyond the octane rating. We will never be able to force Mogas to be produced to Avgas standards. Look how hard (almost impossible) it has turned out to simply get ethanol-free Mogas. And ethanol-free is just one of many standards needed to make a viable aviation-grade fuel.

91/96UL is already a certified aviation-grade fuel (Avgas) that can be produced today. 94UL is likely to be easily certified and can be in production in very short time. Either of these fuels can be used by 70-90% (depending on who you quote) of piston engine aircraft. At best, less than 20% could ever use Mogas and many of those require expensive modifications.

So long as Mogas formulation can be dictated at the State level or lower, it will never be viable as an aviation fuel.

Posted by: Kris Larson | August 9, 2011 10:48 AM    Report this comment

Kris, the real experiences from pilots who have used autogas since 1982 refute your claims. If anything, the few issues regarding autogas formulations dictated by local codes have become less of a problem in recent years.

70%-80% of legacy piston engine planes will run just fine on 91+ AKI, not 20%. Most require only an inexpensive paper autogas STC, and 65,000 already have one. Nearly all new LSA planes should be run on autogas, not avgas.

While it is true that ethanol-free is harder to find these days at the local gas stations (except, ironically, in major corn and ethanol producing states), it remains available at many terminals and demand is growing as the public realizes the damage caused by ethanol.

Lycoming has specified a fuel against an obsolete ASTM standard, but Petersen's STCs for many of their engines have been used with great success for decades.

Lycoming's Michael Kraft has stated that the company needed to support autogas, for instance, since the Nigerian Air Force burns the fuel in their Lycoming-powered aircraft. Does anyone believe that Nigerian autogas meets Lycoming's tight requirements, really?

I suggest you read Paul Bertorelli's recent article in AviationConsumer, "The Mogas Option: Plenty of Engine Choices"

Posted by: Kent Misegades | August 9, 2011 11:37 AM    Report this comment

Kent, I've made no "claims" to refute...

However, you claim that 70-80% of aircraft can run using "an inexpensive paper autogas STC". This is absolutely wrong.

Peterson and EAA STCs are very limited as there are virtually no fuel injected (or twin) aircraft listed on either STC. As for “inexpensive” this is direct from the Peterson STC:

“The airframes we have flight tested which failed the test include the Navion, Musketeer, Piper Apache PA-23-235, 7KCAB, Mooney M-20-C, Piper PA-24 250 Comanche & the Avcon converted 180 hp Cessna 172. Generally speaking, any pump fed airplane not already on the approved list is incapable of passing the flight tests unless substantial modifications are made.”

And:

“We do not have an STC for any engine with Bendix fuel injection. Continental fuel injection is approved - I0-470 -J or -K (225hp). The 260hp I0-470 and 285hp I0-520 are also approved but we no longer support this series of STC.”

Oh, and Lycoming's "obsolete ATSM standard" is actually a decades newer standard than both as EAA's and Peterson's require D-439 ATSM standard.

“Pump Gas” will never be a truly viable option for aviation. Specially blended Mogas could be used for a small number of (low usage) aircraft. Since we need a dedicated aviation fuel, doesn’t it make a lot more sense to have a true aviation-grade fuel like 94UL or 91/96UL AVGAS that can be used by 70%-90% of the fleet without modification (or STC)?

Posted by: Kris Larson | August 9, 2011 12:57 PM    Report this comment

"Pump Gas” will never be a truly viable option for aviation."

The rest of the world has a different opinion. AvGas is the lame duck in aviation.

Posted by: Mark Fraser | August 9, 2011 1:17 PM    Report this comment

Kris,

Here's what I see as an EAA chapter president, aviation writer and as a supplier to GA airports around the US:

Some 65,000 aircraft have obtained autogas STCs from the EAA or Petersen since 1982. That represents 40% of the current piston engine fleet (165,000) according to GAMA. The FAA registry some years ago showed that 70% - 80% of piston engine aircraft are covered by these STCs, and the vast majority (= not all) require only a paper STC for hundreds of dollars. Some do require engine modifications, but it is easy to do the math to see if this makes sense for a given airplane owner.

Nearly all new LSA aircraft use engines (Rotax, Jabiru, ULPower, auto engine conversions) that are best run on autogas, and the LSA sector, while still small, is the fastest growing sector in GA. A number of these manufacturers (Tecnam, Flight Design, Pipstrel) now have or will soon have 4+ seat aircraft whose Rotax or Lycoming engines run on autogas.

All these facts refute your claim that autogas is not a viable option for aviation. If anything, it is hard to make a case in the future for anything other than autogas and Jet-A.

That does not mean that airports should not sell 100LL, 100UL, 94UL if the market will bear all these options, and more options are better in order to maintain the value of aircraft that need high-octane fuel. Let the markets determine between the winners and losers, and let's all work together to keep GA alive, not force one fuel onto everyone.

Posted by: Kent Misegades | August 9, 2011 1:43 PM    Report this comment

> The “specialness” of Avgas goes far beyond the > octane rating. We will never be able to force > Mogas to be produced to Avgas standards.

Surely the fundamental problem is to get an avgas specification that is close enough to modern mogas that refineries are willing to produce it? It can have aviation-specific requirements and still be profitable to manufacture and distribute through the existing avgas channels, but there is no way the refineries will ever produce a fuel as aviation-specific as the LL series.

sPh

Posted by: Steven Healey | August 9, 2011 1:56 PM    Report this comment

I'm sure you are all aware that "Mogas" is a moving target, at least in California. We have different blends for Northern and Southern California. In turn, both blends are "seasonably" adjusted.

I don't know the reasons for this, but that is what pilots here are faced with.

The few people I know at small airports who try to use mogas from the local corner gas station test a sample before buying a full tank. There is a reason for this I assume. I'll ask next time I encounter someone.

Large airports, with the bulk of GA aircraft, and activity, do not have anything other than 100LL at the FBOs.

And the airports (and TSA) do not allow bringing any fuel through the gates.

Posted by: Edd Weninger | August 9, 2011 2:56 PM    Report this comment

Sorry we can't edit posts, meant to add:

Good luck to you guys anyway.

Posted by: Edd Weninger | August 9, 2011 2:58 PM    Report this comment

Well Kent, as an officer in an organization that sells the Mogas STC, your opinion might be considered a bit biased…

You’re mixing and matching your statistics to meet your (preconceived?) results. The number of STCs sold in no-way correlates to number of actively flying aircraft (unless buying the STC somehow guarantees that your aircraft will continue to be actively operated for at least an additional 30+ years).

One obvious limitation of the Mogas STC is that no Bendix fuel injected engines (Lycoming) are allowed to use Mogas. That means all Arrows, most Cherokee 6, Lances, Seminoles, Saratogas, etc., DA40 and all post-1997 172 & 182.

There really isn’t a lot of difference between what is required by Lycoming and the Mogas STCs. It’s just that Lycoming is going out of its way to communicate what is truly required while many of the STC users are choosing to be willfully blind.

If I could get reliably get ASTM D4814 Mogas fit-for-aviation, I’d use it. But assuring that quality means a dedicated supply chain. That supply chain would be better served providing a higher octane (94UL or 91/96UL) that can be used by the majority of aircraft without modification.

Posted by: Kris Larson | August 9, 2011 3:48 PM    Report this comment

What happened to G100UL?

Posted by: John Ewald | August 9, 2011 4:16 PM    Report this comment

Kris,

I understand that you advocate for 94UL, and that's great, even if you are a potential producer or seller, doesn't really matter to me.

I do not sell STCs, the only ones I know of are the EAA and Petersen Aviation. I am a member of the EAA, but certainly do not gain anything from their sale of STCs.

But I have used autogas, as well as avgas, in my airplanes for many years, and do know something about both. You may not like autogas, but your claims against it are unsubstantiated and do not correspond at all with its three decade long excellent track record. See comments from others in this blog.

65,000 autogas STCs sold since 1982 sure sounds like a fairly strong endorsement to me. How many piston planes are certified today in the US for 94UL? Any?

Autogas is not for everyone. Fuel pumps in some engines are problematic, but in others not a problem. Noone is saying that autogas is ideal for every airplane, but as far as unleaded aviation fuels are concerned, it is affordable, available and certified. None of the other unleaded options are.

I prefer a bird in the hand as opposed to two in the bush.

Posted by: Kent Misegades | August 9, 2011 4:45 PM    Report this comment

If you paid attention to what I actually wrote Kent, you'd know that I actually advocate 91/96UL which is already CERTIFIED for use in 70%-90% of aircraft and won’t void my warranty. With all your “credentials”, you should be aware of all fuel options but you seem to know very little about 91/96UL AVGAS.

As Michael pointed out when he started the thread, "Pump Gas" may or may not meet the specifications required by Lycoming and the STC holders but there is no way to know.

Once Mogas is produced/dispensed to aviation standards and the appropriate taxes paid, it will likely be just as expensive as a true aviation fuel like 91/96UL. The savings people are enjoying now is mainly coming from the fact that quality control steps are being bypassed.

When my plane needs a nut/bolt/washer I can run down to Lowes and buy something that will probably work just fine for a few cents. But I don’t. I buy what the manufacture specifies; AN hardware from aviation suppliers that can provide documentation. I pay at least 10 times more, but I know that my plane will be airworthy.

When my plane needs fuel, I can run down to Sam’s Club and buy pump-gas that will probably work just fine. But I don’t. I buy what the manufacture specifies; AVGAS from a source I can trust. That way I know my plane will be airworthy.

Why should I put something that wasn’t aviation-grade in my tank when I won’t use something that wasn’t aviation-grade to mount the tank?

Posted by: Kris Larson | August 9, 2011 6:50 PM    Report this comment

So Kent, what do you propose I do with my 300HP IO550?

Posted by: Brad Vaught | August 9, 2011 7:36 PM    Report this comment

Kris, read the autogas STCs and fuel specs, for instance, from Rotax. Autogas as one can buy it at hundreds of terminals meets these specs and has been used with great success for three decades. It is an FAA-approved aviation fuel, period.

Brad - As autogas supporters have stated many, many times, it is not a fuel for everyone, and it is not a drop-in replacement for 100LL for all aircraft. The Petersen/AirPlains ADI system might one day be available for the IO-550, at a cost of course. On the other hand, for many aircraft, leaded fuel causes major maintenance issues now, and for most aircraft owners has more octane than needed, making flying more expensive than needed.

I do not understand the animosity towards those of us who advocate more fuel choices. Why not embrace them all - 100LL, autogas, 91/96UL, 94UL, 100VLL, 100UL, Jet-A, etc. and allow the free market to determine which are best mix at a given airport? Isn't that in essence what Michael Kraft is saying, adapt to conditions at hand?

Posted by: Kent Misegades | August 9, 2011 8:03 PM    Report this comment

Kris, read the autogas STCs and fuel specs, for instance, from Rotax. Autogas as one can buy it at hundreds of terminals meets these specs and has been used with great success for three decades. It is an FAA-approved aviation fuel, period. Federal aviation fuel taxes are paid by FBOs for autogas, just like avgas, and in most states the aviation fuel tax is quite a bit less than combined federal + state highway taxes on autogas bought at the local gas station.

Brad - As autogas supporters have stated many, many times, it is not a fuel for everyone, and it is not a drop-in replacement for 100LL for all aircraft. The Petersen/AirPlains ADI system might one day be available for the IO-550, at a cost of course. On the other hand, for many aircraft, leaded fuel causes major maintenance issues now, and for most aircraft owners has more octane than needed, making flying more expensive than needed.

I do not understand the animosity towards those of us who advocate more fuel choices. Why not embrace them all - 100LL, autogas, 91/96UL, 94UL, 100VLL, 100UL, Jet-A, etc. and allow the free market to determine which is the best mix at a given airport? Isn't that in essence what Michael Kraft is saying, adapt to conditions at hand?

Posted by: Kent Misegades | August 9, 2011 8:09 PM    Report this comment

I agree with Kent's assertion that we aviators seem to be arguing amongst ourselves towards no good goal.

Kent does not assert he will provide for Brad's IO-550. He is promoting a solution for others in GA.

I need a 100LL drop-in to power my low-engine time 340 to get me where I need to be. I support AOPA and others in their efforts to get this done.

However, I do not oppose Kent's efforts to make an an alternative fuel available for others.

It may seem that sometimes I have a negative view about that, as I post significant issues that Kent and others will have, but no animosity intended.

However, I will question the assertion that one can buy from terminals. If the one is a business making significant purchases, maybe they can buy to specification. If the one is an individual, no way.

Posted by: Edd Weninger | August 10, 2011 12:32 AM    Report this comment

Kent, you’re telling me to read the Peterson STC? Did you not notice that I quoted it?

Not only have I read the EAA and Peterson STCs, I’ve read the Rotax manuals as I owned a 912 powered SLSA and I’ve even studied the TCDS for my other Lycoming powered aircraft as well as Lycoming S.I. 1070. That’s how I learned that they are already certified to run on unleaded 91/96UL AVGAS. 91/96UL that you didn’t even seem to know existed even though you claim to be an EAA Chapter President, Aviation Writer, and “Supplier to GA Airports”.

The reason we are facing the 100LL “crisis” is that the GA community has been duped into believing the lie that 2 aviation fuels are too expensive to distribute. Adding a third fuel to the mix, aviation-grade Mogas, is just going to further fragment the market. Of the active GA fleet, too few can use Mogas to make it a viable option but EVERY aircraft that can run on Mogas can also run equally well (if not better) on 91/96UL and likely 94UL (when and if it is ever certified).

As far as I’m concerned, those of you who choose to use “Pump-Gas” can continue to do so at your own risk, just don’t pretend that “Pump-Gas” is a viable aviation fuel for the rest of us who are truly informed.

Posted by: Kris Larson | August 10, 2011 12:57 AM    Report this comment

Edd, thanks for the clarification. I'm all for multiple solutions, including that from Mr. Larson. You are correct about terminals - they do not generally sell to individuals. But thousands of small fuel companies (jobbers) around the country haul fuel from them daily, probably driving right past most of our airports to deliver to our country's 110,000+ gas stations. The infrastructure for Avgas/Jet-A is tiny by comparison.

If we ever hope to lower the cost of flying, we need to take every opportunity to tap into larger production volumes, for instance in engines (Rotax, auto conversions), avionics (iPAD) and fuel (autogas). Boutique stuff is always more expensive.

I suggest you check with AirPlains of Wellington, KS, on the potential certification of the Petersen-developed ADI injection system for your 340 (nice airplane!) that would allow it to run on autogas one day.

I do not expect 100LL to disappear overnight, really. Even though airports in Europe have been removing 100LL tanks in some places due to lack of demand, I am not aware of any issues with its supply there. I also do not expect environmental groups to push so hard in the US that they'd do harm to GA. If they see us moving part of the fleet to lead-free autogas, that ought to be proof that we're doing something about this nagging issue.

Posted by: Kent Misegades | August 10, 2011 6:59 AM    Report this comment

Kris,

I am really glad to see we agree on something - why should we accept a single fuel solution, after all, many quiet, small GA airports have scraped together their pennies to add Jet-A fuel in recent years in the hopes that corporate aircraft would find them.

You are clearly the 91/96UL expert, so please educate me on the engines and airframes that the FAA has approved for it. I am only aware of the European EASA approvals that the FAA has not yet recognized.

Clearly my information is not up to date on 91/96UL. I have urged Lars Hjelmberg for the past two years to find a means to produce his fuel in the US. I know that he is frustrated that the FAA has not accepted the EASA's blanket approval of his fuel, which I reported on last November in our GAfuels blog at GAN.

Again, I am all for as many solutions as the market will bear. For many of us, autogas is ideal, and has a great track record since 1982. As far as pump gas goes, the reality of ethanol today means that the best supply is to be found at terminals where it is easier to verify that it meets our needs.

Posted by: Kent Misegades | August 10, 2011 7:15 AM    Report this comment

The problem that I have not read is that when I asked the local FBO to get "pump gas" w/o ethanol or "mogas" I was told that it was impossible because his insurance would not let him.

Posted by: Roger Kempfer | August 10, 2011 7:31 AM    Report this comment

Roger, I suspect your FBO receives his fuel insurance coverage through his Avgas/Jet-A supplier, which is typical. Since none of the major avgas suppliers offers autogas (yet), understandably they are not willing to cover sales of autogas from another supplier. Many aviation insurance companies are happy to provide the coverage, and it can cost well under $1000 per year. AUA in Greensboro, NC, is one company, there are plenty of others. Check also with your own airplane insurance provider; many offer FBO fueling coverage.

Posted by: Kent Misegades | August 10, 2011 7:55 AM    Report this comment

Over the past 2 years I have made 18 round trips between MN and CO using mogas purchased at KSGS and KLMO. These flights were made on very hot days, cold days, at higher altitudes (10K or 11K), in an STC'd, fuel injected airplane, without troubles. The plugs are clean, valves don't stick, and the engine is free of gray lead sludge.

The arguments against mogas presented in earlier posts are weak, given approval by the FAA, many years of successful use in thousands of planes, and absence of AD's. Variations in mogas composition appear to be well tolerated by aircraft.

Edd - The only testing that I am aware of pilots performing on mogas purchases is for the presence of ethanol. This is to verify that the "non ethanol" sign on the gas pump is correct.

Mogas has actually improved since the original STC's were granted. The EPA requires a lower RVP to reduce evaporative emissions, which increases the boiling point and reduces the possibility of vapor lock.

Posted by: Dan MacDonald | August 10, 2011 8:44 AM    Report this comment

We sell 93 octane mogas at our FBO in Albert Lea, MN. (KAEL). It is produced by Kock Refining in Pine Bend, MN--the same refinery that produces jet fuel and 100 octane. The quality controls are the same as 100 octane, and the delivery system is by Wayne Transport, using dedicated trucks and drivers.

I mention this because in all of the years SELLING Mogas, and thousands of hours of USING it ourselves in our fleet of Warriors and Skyhawks, we have never had a fuel-related incident. If you live within a 500 mile radius of Minneapolis, your airport can buy it as well.

The down side--even with all of these STCs, and all of these stringent controls, we sell very little MOGAS--even though the price is $1 a gallon less than 100 octane. When we see an auto fuel STC on an airplane, we always ask--"100 or Mogas?" Very few STC holders opt for the Mogas. You have to ask "WHY?"

I believe it is the uncertainty of the fuel specs, and the smell. The smell is put in at the refinery--that should be able to be handled. As to the uncertainty--why not take a page from the farm fuels handliing--color code AVIATION MOGAS red, so that pilots know it meets specs?

Posted by: jim hanson | August 10, 2011 9:03 AM    Report this comment

Wish we had an edit function--that should be KOCH refining.

Posted by: jim hanson | August 10, 2011 9:05 AM    Report this comment

When we see an auto fuel STC on an airplane, we always ask--"100 or Mogas?" Very few STC holders opt for the Mogas. You have to ask "WHY?"

I think you and I discussed this before. This is a common attitude that came up in our surveys. A buck a gallon difference is not enough to erase the slight doubt about quality and specs--even for owners burning 8 GPH or more.

Our surveys turned up two issues: One related to long-term storage and varnishing and several vapor-lock stoppages. The stoppages I'm a little doubtful of because the data wasn't there to support the outcome. Doesn't matter. If the owner lost confidence, he's no longer a mogas customer.

And he's not going to be selling the idea to his hangar mates.

Posted by: Paul Bertorelli | August 10, 2011 9:16 AM    Report this comment

At my FBO, the old "80/20 rule" seems to be right--AGAIN! 80% of the airplanes CAN burn auto fuel, but the remaining 20% of the airplanes burn 80% of the gas. The heavy singles, light and medium twins fly more and burn more.

If the environmentalists want to MANDATE what fuel they want us to burn, let them put their money where their collective mouths are: There is a "SUPERFUND" to deal with environmental problems--I would be glad to put aviation diesels on my Cessna 414--IF the superfund would pay the difference between the RAM engines and the new diesels.

That's the problem with runaway environmentalism--a few people want to dictate what the REST of us should or shouldn't do--and with no consequences.

There's the solution--autogas for small airplanes--and have the environmental funds pay the Delta for the conversions.

PERHAPS, when faced with REAL CONSEQUENCES of depletion of their Superfund, the enviros will decide that there are BETTER issues for them to be concerned about.

Posted by: jim hanson | August 10, 2011 9:23 AM    Report this comment

Paul--"A buck a gallon difference is not enough to erase the slight doubt about quality and specs--even for owners burning 8 GPH or more. "

That is why I'm suggesting the color coding of the fuel--it would assure the user that the Mogas was indeed aviation fuel, that it meets specs, and that it was handled correctly. It would make a HUGE difference in acceptance--at virtually no cost.

Posted by: jim hanson | August 10, 2011 9:26 AM    Report this comment

Acceptance varies by region and airport, to be sure. I recently heard that the Lebanon, OR airports sells twice as much autogas as they do 100LL. Ask also the folks at Lockwood Aviation, or the airports in Barnwell, SC or Suffolk, VA and you'll hear too of the fuel's popularity. It is not for everyone, to be sure, but those who have used it praise its many benefits and cost savings. All the mis-information about it that has been spread through various channels in the past few years has not helped, either. Ignorance regarding autogas by FBO/Airport managers, many pilots, and even major Avgas producers is still surprisingly high. Paul's efforts to get the facts out are helping, however, many thanks.

Posted by: Kent Misegades | August 10, 2011 9:27 AM    Report this comment

Kent said- "...I also do not expect environmental groups to push so hard in the US that they'd do harm to GA. If they see us moving part of the fleet to lead-free autogas, that ought to be proof that we're doing something about this nagging issue..."

Not quite! In California there is a group currently threatening to sue both refiners and vendors of 100LL for poisoning the environment. This includes both large and small FBOs.

They have seemingly said they would withdraw the threat of a suit if an out-of-court settlement is reached.

Sounds like 'Al Capone' extortion to me, but it is apparently legal.

Posted by: Edd Weninger | August 10, 2011 10:40 AM    Report this comment

I purchased my Warrior in 1984 and shortly after that got the STC for mogas. Have never used it. Why? All the info that I have read said to never use it because of the rubber seals, connections, etc. I am not an A&P but over the past 20 years I have never had one to tell me that it is OK to use it. Further I have received letters from Lycoming telling me that although there is an STC for it that it was not recommended in their engines. I put a new engine in it in 1994 and in bold print I was told NOT to use it. That's why it doesn't sell and I would be happy to save a buck or more a gallon at todays fuel prices. The flying public in small aircraft have been warned too many times, in too many "official" publications not to use it. Even the LSA groups I have talked to tell me that they use 100LL because it's not easy to find and you don't have to lug 5 gal. can around. On a cross country trip it's just about impossible to find enough airports on your route of flight that have it.

Posted by: Roger Kempfer | August 10, 2011 11:35 AM    Report this comment

Much ado about nothing.

A bunch of flim-flam nonsense to scare the bejesus out of American aviators!

The Lycoming article and blog, above, pretend as though there really is a 100 octane gasoline available to motorists and aviators, when there is only heptane gasoline available, with various ratings due to different blends of additives.

Like many, I've been using mogas, yes, pump gas, for over 20 years, without incident, with clean valves and plugs, and combustion chambers, and an absence of grey lead sludge in my crankshaft and crankcase.

My six cylinder engine was engineered for low octane gasoline, an 80 "octane" rating, specifically.

Does anyone really care, anymore, to be scared out of their wits, by Lycoming and the FAA? These people have stifled GA in the USA, and unbelievably, have sent GA running to China!

The Chinese don't really care what the control freaks say here, they will run squid piss if they want, and eat scorpions for box lunches, too!

Posted by: Ron Brown | August 10, 2011 12:27 PM    Report this comment

So...can I use other fuels in my 1962 Beech Musketeer with an O-320D2B engine?

Posted by: Francis Butler | August 10, 2011 7:25 PM    Report this comment

So...can I use other fuels in my 1962 Beech Musketeer with an O-320D2B engine?

Posted by: Francis Butler | August 10, 2011 7:25 PM    Report this comment

After all the comments I've seen here, I still don't get the "warm fuzzies" such that I'd go out and do what's necessary to try "pump" gas in my Mooney. I've seen too many conflicting things here with no clear support either way. Not enough case studies to support that within reason I will not see problems. There is also not enough clear evidence that it is unsafe to run "pump" gas. I can say that after reading the article, Lycoming raises some good points and supports them well.

I know, there are people who have been running "pump" gas successfully for years. But that is not suitable evidence for me to decide to give it a try and be the one, maybe in a million, that experiences vapor lock in flight, or costly repairs to rubber seals, or detonation, etc.

There is also the availability factor that's already been mentioned.

So if someone can, please point me to facts and figures that can convince me that the probability of failure while using pump gas is low enough that it meets my personal risk factor. Then I'll start to seriously consider it as a viable replacement for the entire fleet.

Posted by: steve egolf | August 11, 2011 8:20 AM    Report this comment

Figures? How do you seperate the bozo that simply fills up 5 gallon cans of an UNSPECIFIED fuel at the local gas station, stores it in 5 gallon cans in his hangar, and uses it in a non-STC aircraft installation from a an operation that

Buys directly from the refiner Has a certificate specifying date, RVP, Octane, no alcohol, etc. Has a "chain of custody" for handling with a trained transport company?

ANY problem involving mogas caused by those who don't check will be blamed on the fuel.

MOGAS will not be accepted until it can be DOCUMENTED for properties--IDENTIFIED as such, and has the approvals of the airframe manufacturers, engine manufacturers, and the FAA. Only after these quality controls are met will people accept it. Fortunately, most of these approvals and tests are already in place.

If any fuel meets these approvals, it needs to be identified as such--put red dye in it so that skeptics can identify it for what it is.

Posted by: jim hanson | August 11, 2011 8:34 AM    Report this comment

Steve, STCs for autogas have existed since 1982. To obtain them, the owners (EAA and Petersen Aviation) must subject a given engine/airframe combination to exactly the same rigorous tests as for Type Certification. The toughest part of these tests involves heating the fuel on the ground, then rapidly climbing to altitude. If the engine coughs once, no STC. That's why there are none for the Mooney - some issues with the fuel pump, I understand. If a Mooney owner still uses autogas, they are as guilty as if they had topped off with Jet-A. As long as pump gas is D4814 compliant (it all is these days), contains no ethanol, has the minimum AKI octane rating as required by the STC or TC, and has not been sitting in a tank for over 6 months, it is safe to use, and that is according to the FAA. The RVP vapor pressure is also no longer an issue as modern fuels and engine controls allow cars to run well on RVP of 9 or lower. Avgas has its share of problems, too: poor condition of tanks/filters at many airports, water contamination, lead deposits, lead emissions to the environment, and it too can cause vapor lock under certain conditions. Using pumpgas, mogas, autogas, or whatever you want to call it has nothing whatsoever to do with luck and those that claim this insult the hard, costly, thorough work of the EAA, Petersen Aviation and the FAA who have approved its use for three decades.

Posted by: Kent Misegades | August 11, 2011 9:07 AM    Report this comment

Why is it that the EPA and other wackos don't have to prove that leaded avgas causes cancer. They get a pass on any stupid idea they decide to push.

Posted by: kent tarver | August 11, 2011 10:15 AM    Report this comment

Kent, I agree with your comments re: the testing that was done and would use it if I could find it w/o lugging 5 gal. cans around which is not practical on a cross country flight. I have searched the internet and there is a list of airports which have mogas. In VA there is only one and it's the opposite side of the state. FOB's who don't carry it simply say it's an insurance/liability problem and not interested. What I find really interesting is that you find it w/o ethanol the most in the corn belt states.

Posted by: Roger Kempfer | August 11, 2011 11:47 AM    Report this comment

A few days ago Mr. Kraft specified engine conditions for their fuel cert, one of which included 500F CHT. I cannot find it now. Did it get edited out?

George Braly, Walter Atkinson and John Deakin of advanced pilot seminar and GAMI engine test cell fame state bluntly that CHTs above 450F is engine homicide and leads readily to heavy detonation. CHT relates directly to detonation margins and hence octane requirements. Owners can avoid detonation by installing a multi-probe engine monitor configured to alarm at 400F to remind the pilot to manage engine cooling and avoid detonation.

Lycoming's 500F limit implies the pilot is just a passenger or ignorant. I'm not saying all installations are well designed, but minor mods can drastically reduce CHTs to a max of 400F climb and 380F cruise where detonation cannot occur.

Posted by: tom connor | August 11, 2011 11:53 AM    Report this comment

Roger, agreed, lugging fuel is a pain, which is why I recommend working with your FBO to get quality autogas delivered to your airport. It is available at two places in VA, W90 and KSFQ, and a few more will add it this year. The Little Oil Company in Richmond, owned by a pilot/homebuilder, is looking into supplying autogas around Virginia. Insurance is really a non-issue for FBOs who want autogas, policies are available and inexpensive.

Posted by: Kent Misegades | August 11, 2011 12:04 PM    Report this comment

Another simple solution the the auto fuel problem would be electronic ignition utilizing a knock sensor, the way cars have been doing it since the 80's. I have been using pump gas for years, simply back the mags off one degree and insulate your fuel lines to prevent vapour lock. I have 250gal tank in my hanger and fill it from the farm fuel truck. No problem.

Posted by: Ray Toews | August 11, 2011 5:19 PM    Report this comment

I'm always surprised by the people that worry about elastomer seals in their GA aircraft. Where on Earth, do they think we get our elastomer seals? They would not be available to us, except for one thing: the automotive industry. Your car handles the fuel just fine, and the seals for your plane come from the auto industry! How can there be a concern?

Yes the elastomer seal industry is huge, and if you have ever read the data in the catalogs, no seal does everything, but all seals are rated for suitability to various liquids. As time passes, there will be some deterioration, but, it's always to be expected, and it's usually oxidation, which takes years to crack the rubber gaskets on your fuel senders, and O-rings I have seen last 38 years, like the bottom seal of an oleo strut, which is subject to movement wear.

Replacing seals, is really routine maintenance, for anyone with experience. Luckily, the time intervals really stretch out!

Posted by: Ron Brown | August 11, 2011 7:48 PM    Report this comment

I'm always surprised by the people that worry about elastomer seals in their GA aircraft. Where on Earth, do they think we get our elastomer seals? They would not be available to us, except for one thing: the automotive industry. Your car handles the fuel just fine, and the seals for your plane come from the auto industry! How can there be a concern?

Yes the elastomer seal industry is huge, and if you have ever read the data in the catalogs, no seal does everything, but all seals are rated for suitability to various liquids. As time passes, there will be some deterioration, but, it's always to be expected, and it's usually oxidation, which takes years to crack the rubber gaskets on your fuel senders, and O-rings I have seen last 38 years, like the bottom seal of an oleo strut, which is subject to movement wear.

Replacing seals, is really routine maintenance, for anyone with experience. Luckily, the time intervals really stretch out!

Posted by: Ron Brown | August 11, 2011 7:54 PM    Report this comment

Kent, Thank you for the information on The Little Oil Co., in Richmond. On the other side of the state from us but will contact them and see if they will contact my FBO. I have tried to discuss the matter with little success. About 75% of the a/c based at our field could use mogas. Thanks again.

Posted by: Roger Kempfer | August 11, 2011 8:19 PM    Report this comment

Roger, Dearybury Oil in Spartanburg, SC, will supply airports in VA/NC/SC/GA/FL/TN with 91+ AKI ethanol-free autogas. They have supplied Barnwell (KBNL) for years. Bill Dearybury understands aviation's needs.

Posted by: Kent Misegades | August 12, 2011 6:41 AM    Report this comment

Kent, Thanks for all the info. I will find out this weekend or when I come back from AK in Sept. who the local FBO gets to supply our fuel. Do you know a company that can supply the western part of VA with Mogas, 100LL and Jet fuel. We have quite a bit of biz jet traffice. Thanks.

Posted by: Roger Kempfer | August 12, 2011 6:55 AM    Report this comment

Roger, contact Mickey Hines, the manager of Abingdon, VA Highlands Airport (KVJI). He can advise you on avgas/Jet-A fuel suppliers in western VA.

Posted by: Kent Misegades | August 12, 2011 7:32 AM    Report this comment

Gentlemen, I have a Cessna 337 Skymaster with IO-360-C/D engines rated @ 210 HP. Can I use mogas in my engines?

Posted by: Gene Pettit | August 12, 2011 10:12 AM    Report this comment

Gene, as far as I know, there are no autogas STCs for the IO-360, probably related to Lycoming's use of Bendix injection which vapor lock with autogas. Contact Petersen Aviation for details.

Posted by: Kent Misegades | August 12, 2011 10:39 AM    Report this comment

Gene - The 337 has never been flight tested and if it were, it would fail given that the engines use Bendix injection. Nor have those engines been detonation tested. Hence the 337 remains an avgas burner.

Posted by: Todd L. Petersen | August 12, 2011 10:48 AM    Report this comment

Gentlemen, I failed to mention I have "Continental" IO-360-C/D engines in my Cessna Skymaster. Does that make any difference as far as the use of mogas in these engines?

Posted by: Gene Pettit | August 12, 2011 8:26 PM    Report this comment

My mistake. It could make all the difference. However it'd still need to go through hot fuel flight testing to find out, and the engines would need detonation and endurance testing first.

Posted by: Todd L. Petersen | August 12, 2011 9:17 PM    Report this comment

"Why is it that the EPA and other wackos don't have to prove that leaded avgas causes cancer. They get a pass on any stupid idea they decide to push.

In the 70's, EPA exclaimed there were huge lead deposits on the side of highways - the result of Leaded Fuels. A few years ago, they proclaim there are huge lead deposits on the highways - due to Lead Tire Weights. I surmise they knew that lead tire weights in the 70's. Did the math one time. GA deposits ~.00000002 oz lead /sq ft/yr. That lead would not stay on the surface, it will percolate into the ground and become even less "concentrated" (as if .00000002 is "concentrated"...). It's re-distribution and dispersion of lead.

Posted by: Marc Salvisberg | August 17, 2011 12:15 PM    Report this comment

Part 2

The oft touted FOE lead pollution at that socal airport? Ground samples were biased and taken on the outside of the runup area. When that fact was brought up by a (their own!) professional researcher (that I talked to), they were not interested in averaging the testing over the airport facility - only the runup area. Even their own hired researcher disagreed with their methodology. I've emailed FOE multiple times on their website asking for airport locations of data and received nothing in return.

EPA and Cal-EPA and CARB are the people who brought us MTBE - and I would not be surprised if MTBE, in the few short years that they mandated it's use in CA has caused as much damage to the environment than all leaded AVGAS ever used.

CARB? The 2011 CA legislature shorted social programs, law enforcement, parks and schools. The Cal-EPA overall budget was not shorted at all. Essentially the same as 2010. California Air Resources Board (CARB) budget? Up 20% and the rest of the CAL-EPA programs? Water, etc? Down 20%.

Posted by: Marc Salvisberg | August 17, 2011 12:16 PM    Report this comment

There is a def power difference in fuel. We are involved in racing where Sunoco 260 GTX is the required fuel. It's 2% TO 3% (and up to 5%) lower in hp output that typical California 91 octane premium. Our "cheating / budget stretcher" for the slower, mid to back pack guys is to run pump gas. Of course, each engine "likes" a specific fuel and the results from our hi compression, high revving engines are likely going to be better or worse than a 2500 rpm / low compression / 2 valve engine. So - what I'd like to see is hp comparisons with the different fuels. I'd sure hate to give up 5% power over the 100LL that I had been using - lord only knows that PA28-140's with 2 people or PA28-160's with a full load or C-150's with anybody in them are happy giving up much power!

Posted by: Marc Salvisberg | August 17, 2011 12:35 PM    Report this comment

Geez! Did I get up this AM on the wrong side of the bed, or what??? :-)

Posted by: Marc Salvisberg | August 17, 2011 12:38 PM    Report this comment

.

Posted by: Marc Salvisberg | August 18, 2011 11:52 AM    Report this comment

I am flying piper Navajo in India.I can buy MTBE in here.Can I just mix 30 MTBE to 91 octane auto fuel and it will become 100 octane.will this work in Lyc TIO540 engine?

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