G100UL: This Is Gonna Be Interesting

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When I was young pup newspaper reporter, I rolled into the newsroom one day at the crack of noon—we were an a.m. daily—to hear a most disconcerting one-sided conversation between the city editor and some unknown entity at the other end of the line. "Yeah, well," he was saying, "it turned out our source was full of s***."

Now this has always been, is and will always be a fact of life in journalism. Journalists talk to people, interpret what they say and write stories. If the sources are wrong, the story is wrong, too. By convention, you figure it out the next day and write a new story or a correction. You kinda hope it doesn't go on for, oh, 25 years.

That's exactly the way I felt when I hung up the phone after talking to George Braly about the new fuel he is testing as a substitute for 100LL. If his suppositions prove true—and, more important, economic—the solution to the avgas problem has been sitting under our noses for nearly three decades. To summarize, Braly is looking into an octane additive that's a known material and is available through the normal course of refining operations. Or more accurately, that's one way to make it.

He declines to say what it is until further testing and economic scratch padding is done, but a quick Web search turns up a host of possibilities. Toluene is one, an additive that's already a blendstock of avgas. There are patents out there for aviation fuels octane-boosted with things like isopentane, n-butane, MTBE and others. (MTBE is an environmental no-no.) I found a paper on using nearly straight toluene as a racing fuel, with good results, except it doesn't vaporize well enough to start in cold weather.

It really doesn't matter what the material is as long as it delivers the octane, does no other harm to the engine and is refineable in sufficient volume to be near the cost of tetraethyl lead. It doesn't have to be cheaper, it just has to be close in cost. And it can't be too good or too cheap, otherwise it will get skimmed off for use in products more profitable than avgas. That's the giant hole in Swift Fuel's economics. If they make 100-octane anything for $3, that giant sucking sound is every refiner in the country buying it for blendstock.

The worst case scenario might be a material that gets 100UL within about $2 of current avgas prices. Compared the specter of losing 100LL entirely, the industry might bite on that and break its nasty lead habit once and for all. Unfortunately, it would usher in the reality of $7 avgas—maybe permanently. Initiatives such as variable timing to accommodate lower octane fuel or other blends are already dying a slow death. An expensive solution that's not too expensive might kill them. But that's the free market for you.

It's too soon to say if G100UL dosed with the mystery octane booster is the real deal or not. Braly tested the fuel, it's got the desired octane and thus good detonation characteristics. GAMI and TAT have a good track record for delivering on their research, but they're not infallible. We'll know more in a month or two.

Coming full circle here, we've been told for years that researchers have tried everything from Thunderbird wine to Unobtainium Oxide to boost octane, but nothing worked or if it did work, the economics didn't. And we, as journalists, pretty much bought that and wrote our avgas Chicken Little stories because that's what our sources told us. So maybe the research wasn't done well or at all. Maybe it was just lazy science.

If they've been wrong all along, and the avgas crisis resolution comes out of a T-hangar project in Oklahoma, I for one will be most amused.

Comments (36)

True : it will most likely be priced right on that most annoying sweetspot of $7 or so. But what did happen to electronic ignition and low-octane fuel ? I think I once read that 80% or so of the GA engines were tested on low-octane fuels way back then. I found a Motorhead article from 2005 on the subject, but little news recently. Anyone ?

Posted by: Peter De Ceulaer | December 10, 2009 3:17 AM    Report this comment

If 'they' can make the change for the world's squillion or so cars from Leaded to Unleaded, then it can certainly be done for aviation. Trouble is - as mentioned above - there just isn't money in aviation. The only way to make a small fortune with aviation is to start with a big fortune.

Posted by: Darren Edwards | December 10, 2009 5:47 AM    Report this comment

$7 avgas? Stick a fork in general aviation 'cause it is done. $4 gas has just about killed it. For me, my Cub is a toy. I don't have a Harley, I don't have a boat, I have a Cub. At $7 a gallon it is going to be a very dusty Cub.

Posted by: Jim Doody | December 10, 2009 6:14 AM    Report this comment

7 dollar avgas?? See ya, I am outta here. I sure hope the price of aluminum continues to go up.

Posted by: Art Ahrens | December 10, 2009 7:40 AM    Report this comment

PRISM (GAMI's electronic solution) works, but like most alternate fuel solutions, the problem is economics. Don't count it out, but it's going to be hard to convince folks to add it to a C-172 they bought for $30K.

As for $7 a gallon gas... Hah! I paid almost that ($6.50) a gallon for 100LL at Signature at DAL last week. And that was with a discount. Others had their gas for $6.90, and the cheapest on the field was $6.00. So we are talking about $9 per gallon gas - and recall that Avgas is already way down from what it was a year ago.

Posted by: JAMES M KNOX | December 10, 2009 8:26 AM    Report this comment

I agree with comments of free market capitolism and the issues with Swift fuels, but I cant see where the price would almost double. There are a lot of "institutional costs" with LL fuel, that one hopes would transfer to this new "stuff". Maybe the $7 number is just to test the water.

Posted by: Burns Moore | December 10, 2009 8:28 AM    Report this comment

I agree with the above sentiments that even todays gas prices are surely killing GA. They are also doing a good job of killing the airlines. We desperately need a $2/gal fuel, and we pretty much need it to be made from something other than petroleum. And not just for airplanes -- infinitely much more so for cars! We are handing way too much money to our enemies.

Something like Swiftfuel is probably the answer. If the Brazilians can figure this out, why can't we?

Posted by: Anthony Vallillo | December 10, 2009 8:34 AM    Report this comment

Swiftfuel's underlying biological process has been known for almost a century. However the promise of unlimited cheap bio-fuel ignores the zero-sum problem of competing agricultural resources for producing food at an acceptable cost. We have to eat before we fly. If you want to pay $3 for a single ear of corn, then we can make all the bio-fuel we want.

As for the economics of refinery-based solutions, we should keep in mind that if the refineries could provide a stream of 100% iso-octane we would already have 100 octane fuel. The other stand-ins for iso-octane have been around on paper for decades. Since there is no way that we can know how much of big-oil's pricing of such alternatives will be opportunistic gouging triggered by favorable regualtory support for lead's demise, $7 per gallon does not seem out of the question.

One of the excuses for the high price of avgas has always been the distribution cost. If we can deliver unleaded avgas in the national pipelines, and the price at the pump still rises to $7 per gallon, somebody is going to make a lot of money on scrap aluminum. Heck, continued prices of $5 per gallon coupled with the growing indigestion with DHS/TSA/CBP/FAA regs will relegate personal use of GA to a small fleet of 2-seat flivers running on an auto-gas STC.

Posted by: David MacRae | December 10, 2009 9:55 AM    Report this comment

The prices in Dallas haven't come down much at all. ADS and DAL were charging well into the $6.00 range during the last spike...and they apparently still are. Go a few miles out of town and the price drops to the $3 - $4 range. Distribution costs are part of it...trucks will always be more expensive than pipelines, but another part is that in some markets they just charge high prices because they can.

Posted by: Chris McLellan | December 10, 2009 10:58 AM    Report this comment

I should have noted that the $7 figure is no one's guess but my own. It could be less. It could be more. Also, there are some economies in not having to handle the lead at the refinery, in the tankers and the pipelines. I don't know how meaningful these are.

Posted by: Paul Bertorelli | December 10, 2009 11:54 AM    Report this comment

The really best solution is for aircraft to able to use MOGAS (I used PEMEX service station stuff in my C-175 in Mexico). It will always be cheaper and available. I can't get a straight answer on what efficiency/horsepower we gain going from something as low as 80 octane but, but, as I recall, old Lycoming engines went from 150 HP to 160 (Tri-Pacer). Big deal, a 7% gain in power for a 41% increase in price (and that's for 87 octane not 80 octane) and I am using the cheapest AVGAS in the state. What is the percent HP gain going from 91 octane to 100 octane? Anybody really know and can actually document this?

Posted by: ARTHUR THOMPSON | December 10, 2009 12:28 PM    Report this comment

Unleaded premium auto gas that is not blended with alcohol would make for a very inexpensive alternative fuel for a large number of aircaft, including those already holding an STC and those which might qualify for one.

But getting the unblended premium out of the pipelines and distributed out to airports is the problem. The fuel distributors would need trucks with additional tanks for this lower octane fuel. Airports would need an additional tank and vending system.

We have been trying to solve this problem in New Mexico but there are a number of hurdles to be overcome. And we can't even get good statistics on how many customers might be able to use unblended premium, and how much they would use each year.

This option, however, also needs careful study and a nationwide solution implemented if warranted.

Posted by: Rol Murrow | December 10, 2009 12:32 PM    Report this comment

I am in upstate New York and drive about 20 miles to Pawlet VT for ethanol free Mobil gas. They have all 3 grades ethanol free and do not sell gas with ethanol, they expect to have it for at least another 12 months. Paid $2.75 for 87 and run it at a ratio of about 4 or 5 to 1 with 100. Works great in my 0200.

Posted by: Jim Doody | December 10, 2009 12:47 PM    Report this comment

Why is it that so many of us that fly airplanes which require only Low-Octane...have to pay so much money to keep High-Octane fuels available to high-compression drivers? Remember when Good Gulf and Conoco simply allowed the consumer to "dial-in" the desired octane AT THE PUMP?
Given the choice, I'd gladly fly my little Cessna on avgas that is UN-leaded ...and let the guys who need 100-octane PAY for and get their lead ADDED AT THE PUMP! How difficult does this have to be?

Posted by: George Horn | December 10, 2009 12:58 PM    Report this comment


The problem involves the supply line and the delivery systems.

FBO's and airports are happy to have only one tank with 100LL serving all avgas customers. And the delivery trucks only need one tank. (We won't talk about jet fuel here.)

Except at busier airports the aircraft fuel market is not very big. With all the environmental and other restrictions it is very expensive to think of adding another tank and a blending system at every airport fueling location.

And then all the delivery trucks would have to have a second tank, too.

The interesting thing is that here in New Mexico the autogas is delivered by pipeline in two grades. It is not yet blended with alcohol. It comes in roughly 88 octane premium and 84 octane regular, prior to blending. These numbers are approximate.

The depot blends in the alcohol and any other additives as the fuels are loaded onto double trucks for distribution to gas stations. The alcohol raises the octane a few points.

So at the pumps you get 91 and 87. The middle grade is a mix of the two. Some pumps can mix a number of ratios for other intermediate octane values.

To provide both a high octane fuel for all the high performance aircaft AND a lower octane fuel for the light aircraft would mean a doubling of the current avgas truck capabilities and airport delivery systems. And it means some way of supplying and delivering a 100 octane equivalent fuel, possibly by taking unblended premium and adding an octane enhancer.

Posted by: Rol Murrow | December 10, 2009 2:52 PM    Report this comment

A few years ago NASCAR switched from a leaded high octane fuel to Sunoco GTX, which is an unleaded fuel with an additive to replace the lead. There were no changes required to the engines and no degradation in performance. Has anyone investigated that fuel for aircraft use?

Posted by: Matthew Carson | December 10, 2009 2:58 PM    Report this comment

Who let copyboy Bertorelli near the linotype machine again?! ;-P Can't somebody around here police that whipper-snapper??

Hey, like most aviashun intel-lecshuals, I worship the ground Reverend Braly strides upon, but in the analogy of journalistic dead-ends and bum sources, this time it's got to be our man Braly. An additive that's been sitting under the noses of the entire petroleum industry for 30 years? Just waiting to be patented into a new AvGas mix? Sounds too much like that Apollo moon landin' they faked a few years back (o.k. 'decades' back, I'm old. Sue me). There's been a lot of fellas in the petro-oleum bizness just beggin' to dump the lead contaminatin' their process equipment, and you think they overlooked this? And besides the cost incentive, what about the money incentive?

Naw, I hate to say it, but something won't test out here. Sure it'll come out to equal 100 ocatane, or whatever George sez (the man knows his numbers), but over 2,000 flight hours sumthins gonna rust up or wear extra hard or gum up the works. If this high faloutin' snake oil was right under our noses it would've been found before now, just like the cookie crumbs in my moustache.

Posted by: Bradford E. Willmore | December 10, 2009 2:59 PM    Report this comment

Well, there sure isn't any shortage of junk science out there, and the environmental movement seems to have more than it's share of practitioners, many of whom will be at the meeting of their mutual admiration and fraud society meeting in Copenhagen shortly.

Hopefully, cooler (no pun intended) heads will prevail in all aspects. I have my doubts.

Posted by: Ronald Cox | December 10, 2009 3:48 PM    Report this comment

It wouldn't take as much trouble as it may seem to put TEL in a seperate tank and add it at the hose. It wouldn't take a seperate tanker-truck each time fuel is delievered. It'd only take ONE delivery of TEL occasionally to re-supply the TEL tank. (in my un-petroleum-industry opinion.)

Posted by: George Horn | December 10, 2009 4:09 PM    Report this comment

It's not just the EPA & the Clean Air Acts; it's also the Energy Independence and Security Act of 2007 that requires 15 billion gallons of grain-based renewable fuels (ethanol) to be used by 2017. According to the AOPA, only 30% of the piston-powered aircraft in GA really need the 100LL octane boost but this translates into 70% of the consumption. Other low-performance engines/planes would be better off getting STCs for their engines and airframes from either the EAA or Petersen Aviation in Nebraska. EAA's autofuel site claims more than 40,000 STCs for Mogas have been issued since 1982. Seems to be the quickest fix granted premium unleaded non-ethanol Mogas remains available especially since 51% of Mogas available today is already blended with ethanol (according to AOPA since March 2008). Anyone ever heard of the Swedish company Hjelmco Oil? It's got unleaded 91/96 fuel and was developed back in 1981. It was supposed to have started certification with the FAA but can't find any info on it. It's only available in Sweden and Japan. Anyone know anything about it?

Posted by: Marcellette Cloche | December 10, 2009 4:39 PM    Report this comment

Is a blend of heptane/Mogas feasible? If so the cost should be 'bout the same as 100LL. As for delivery/storage, those Texas patches are closer to the source and tankage cost is smoke and mirrors.

Posted by: Larry Fries | December 10, 2009 5:32 PM    Report this comment

OK, some interesting ideas but if MOGAS becomes the really ECONOMICAL option then: a)What is the highest octane we could EASILY purchase without ethanol? b) If 100 octane engines are derated by lower compression pistons to accept this MOGAS (say 90 octane) what is the percent power loss? I am sure we will be able to get ethanol free fuel if it becomes THE standard.

Since I have and older Cessna 210D I have plenty of excess power (e.g. I once got to a DA of 24,000' no turbo and moderate load). I would trade a 5% loss in power for a 30% drop in fuel cost. This cannot be intelligently discussed until we KNOW the power loss.

Posted by: ARTHUR THOMPSON | December 10, 2009 6:05 PM    Report this comment

If 100LL goes away without a 100 octane equivalent, kiss GA as we know it goodbye. Right now there are many recreational pilots struggling just to keep flying as it is. Throw in a several thousand dollar mod to get LESS performance and they will just bail. One of my planes has a XP360 with 9.5:1 pistons and can't run less than 100 octane. I think the current administration would like nothing more than to get rid of all those carbon emitting recreational pilots. I just don't see the trends as very positive right now and the way things are going with regards to discretionary income, a vast swath of GA is going to be extinct in the very near future.

Posted by: daniel schultz | December 10, 2009 7:28 PM    Report this comment


I would like 100 octane too but wouldn't you exchange 5% less power, which would be a 1.5% decrease in top speed and possibly NO decrease in cruise under 7000' since you could simply cruise at the same HP (a higher power %), for a 30% decrease in fuel costs? My flying is not much affected by a couple of knots cruise speed nearly as much as it is by fuel costs.

The last time I bought pistons they were about $50 and I can top my own engine in a long weekend.

Posted by: ARTHUR THOMPSON | December 10, 2009 8:15 PM    Report this comment

Well Arthur, I fly mostly acro and my other aircraft are a highly modified Pitts with a Lycon IO-540 that has 11.5:1 pistons and a Stearman with a PW 1340. Although I am an A&P, most other pilots are not. The cost to pay an A&P to make the necessary mods my out weigh the benefits for a lot of the older aircraft. Kiss the warbirds good-by, at least the bigger ones. I just don't see the good side to this at all. As far as fuel burn goes I don't care, with the type of flying I do horsepower rules. Hopefully I am wrong about losing a large percent of GA due to 100LL going away, time will tell.

Posted by: daniel schultz | December 10, 2009 9:35 PM    Report this comment

Since almost all my flying is XC personal travel my concerns are economic and MOGAS will be the last to go and cheapest. Hopefully an additive would be available to boost octane to 100 or even greater for unique cases such as your. But what is even worse is this eco-fanaticism everywhere. I spoke to a Lycoming engineer at Tampa and they have been so bullied by the ecos that they won't dare to point out the ridiculousness of the pollution charge for what is now an infinitesimal fraction of TEL usage compared to the past. Everywhere you turn there is a new federal department to control every aspect of our lives (for the benefit of we inferiors,of course).

Posted by: ARTHUR THOMPSON | December 10, 2009 10:44 PM    Report this comment


Like you, my aircraft is OLD, a 1965 210E. Regardless of which fuel is proposed, expect a problem with certification. First Continental has to sign off on it, and then Cessna. Where do you think our OLD Cessna aircraft will be in the pile when it comes to developing an STC for the use of a lower octane fuel?

That 5% loss in power that you speculate will result, primarily will affect takeoff and climb performance. Cessna isn't going to certify without flight tests to develop a whole new performance profile. The liability risks are simply too great in this litigious world in which we live.

Other factors that will have to be considered are volatility and vapor lock tendencies (perhaps involving mods to cowling and fuel systems), as well as materials compatibility issues that are outside of the purview of the engine manufacturers.

All this can be done, but the will, and the business case for the manufacturers are going to be a problem.

Finally, the FAA and foreign equivalents will have to get involved at some point and that should guarantee that everything will be in place by 2020, assuming that the desired solution can be identified in the next year or so.

Posted by: David MacRae | December 10, 2009 10:59 PM    Report this comment

I do not think Cessna would be that involved but remember that EAA and Petersen STCs came out for 87 MOGAS. You simply pay them for the paper. And many non-Cessna engine mods are out there, original manufacturers were not involved.

It would be extremely easy to determine the results of a 5% decrease in HP either by relatively simple calculations or by flying said plane at a lower MP. If somebody does not want to do something the reasons why it can't be done are endless. Stand somebody against a wall and start loading rifles and all of a suddenly the impossible miraculously happens.

Posted by: ARTHUR THOMPSON | December 10, 2009 11:37 PM    Report this comment

G100UL... unlikely that a team of wrenchers will outshine chemical engineers. But if they do, just remember that the same bunch specializes in putting $100,000 engine conversions into $80,000 planes... can you imagine what the cost might be for their gas?

A new fuel could be STC'd for existing aircraft, including possible aircraft modifications, without the participation of the engine or aircraft manufacturer. That's exactly how EAA and Peterson did the mogas STC's.

Note that some Peterson STC's involved engines that were not originally approved for 80/87 - such as the Piper Warrior and Archer of 160 hp and 180 hp, respectively. However, these require 91 octane, and expensive hardware changes to prevent fuel boiling problems.

Recognize that the high price of avgas is not cost-based. The current US price of 100LL varies from $3.00 to $8.44/gal! The cost of the gas is below the lower number, so the rest is gross margin for the FBO. Using tools like airnav.com are the best bet to keep FBO's competitive.

As long as aviation requires a specialty fuel it will be a problem. Getting the alcohol out of mogas, and increasing availability at airports, is the solution for us low compression flyers. The high compression boys will be SOL.

Posted by: Dan MacDonald | December 11, 2009 5:38 PM    Report this comment

Well Dan I hope for your sake the "High Compression" boys are not SOL. GA needs MORE pilots participating not less. If for example, if I find my self getting out of GA as a result of not being able to fly my planes, FBO's, maintenance, parts, AOPA, EAA, ETC will no longer get my money. Multiply that by thousands of pilots leaving and whoever is left will have to pick up the load. So their costs will go up significantly as well as loss of lobbying power in Washington as there will no longer be any point in supporting GA from those who left. GA runs on LOTS of discretionary income dollars and the margins are getting smaller as it is. Hitting pilots with no substitute for 100LL would have dire consequences for us all in GA. Like I said I hope I'm wrong, but other than a lot of optimistic happy talk I don't see sunny skies ahead.

Posted by: daniel schultz | December 13, 2009 5:21 PM    Report this comment

This sounds like the doom and gloom when 80 octane went away. I'm confident when 100LL goes away, there will be a relatively inexpensive fix to keep us flying. I'm not sure 100LL is the environmental disaster that some are touting, but it can't hurt to get rid of the lead, and maybe we'll get a P.R. boost at the same time. Personally, I've been running alcohol-free mogas for the last several years and I don't miss picking lead out of the plugs!

Posted by: Josh Johnson | December 13, 2009 7:20 PM    Report this comment

When 80 octane went away pilots could still run 100LL. 100LL goes away many pilots will have to modify their aircraft, and some extensively. It's not the same at all. Aside from a small group of busybodies who can't seem to overcome the urge to micromanage other people's lives, there is no good reason to be getting rid of 100LL

Posted by: daniel schultz | December 14, 2009 8:53 AM    Report this comment

This reminds me of the Ben Franklin quote (if I remember correctly) either we hang together or we shall surely hang separately. There is no "us & them" within GA. There is only us. I can understand the 80 guys feeling some sense of "serves you 100LL guys right" but the 80 guys can't live with mogas alone due to the water/ethanol issues. Without GA as a sum total product there probably won't be any GA. We in GA are treading on thin ice, thus we better tread lightly.
Peace to all this most holy time.

Posted by: Burns Moore | December 14, 2009 9:07 AM    Report this comment

When lead was in auto gas we probably emited 10,000 times as much lead as current GA. You can throw out all the technobabble you want to but I survived that era quite well. In fact I live near a town called Galena, a lead mineral. It really worries me how easy it is for causists, in conjuction with the media, to create phobias.

Posted by: ARTHUR THOMPSON | December 14, 2009 8:45 PM    Report this comment

I think one of most interesting aspects of this discussion is not the technical/environmental, but rather the socio/economic. This has become an extension of the class/race warfare battle going on in Washington. The 87 octane population states we don't need 100LL, and by extension the aviation population that requires that specific fuel. Some say that since "I'm an A&P, have XYZ engine that I can fix while watching the half time show, yada, yada, yada", I don't need the 100LL guys. But think for a minute, if the 100LL population is sacrificed on the alter of self-opportunism, what will GARMIN, BENDIX-KING-HONEYWELL, ASPEN, CESSNA HB, et al do as an economic response? My guess is find other economic opportunities and write off the piston GA market. The market will respond to the turbine segment, but for the most part affordable innovation will cease. Eventually even the LSA, EAA and vintage market will feel the effects of NO marketing or political voice. How easy will it be to legislate the little guys away when there are a few left using prime real-estate? Please think about this before crowing "Hurray for me and the devil take the hindmost" We used to call this type of dialog an "intramural firefight" where only the collective group takes self inflicted wounds.

Posted by: Burns Moore | July 31, 2010 8:58 AM    Report this comment


Posted by: sam verma | January 2, 2013 2:02 AM    Report this comment

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