Surprise twist in ongoing avgas debate

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

In a surprise twist in the ongoing debate over a replacement to leaded avgas, the FOE announced on Thursday, May 26, its intent to sue the EPA over what they deem a lack of progress:

“The EPA has repeatedly concluded that lead is extremely toxic to humans, wildlife and the environment and causes a variety of health effects even at low doses,” said Marcie Keever, legal director for Friends of the Earth. “Our letter puts the EPA on notice that we will go to court unless EPA does what the law requires and addresses this pollution. The health of airport workers, pilots, passengers, and surrounding communities from continued exposure to lead in aviation gasoline hangs in the balance.”

The GA Avgas Coalition was quick to respond, issuing a statement that appeared on Friday, May 27. In its statement, the coalition claims that, counter to the FOE’s claims, real progress has been made:

“The threatened suit, alleging inaction on the part of the agency, would ignore extensive work underway or done by the EPA, FAA, and general aviation and fuels industries.”

While your bloggers do not defend the actions, or statements, of either party in this onging debate, we must correct some errors in the comments made by the Avgas Coalition concerning autogas.

“Despite some 40 years of research since the passage of the Clean Air Act, no safe alternative has been identified.”

While it is true that no approved – and affordable – lead-free alternative for 100% of all piston engine aircraft has been identified to date, it is accepted that at least 70% of the legacy piston-engine fleet of aircraft, and essentially 100% of the new fleet of Light Sport Aircraft may, with little or no modification, operate safely and legally on 91+ AKI ethanol-free, lead-free gasoline, aka “autogas” or “mogas.” Autogas has been an FAA-approved aviation fuel since 1982, when the first STCs were issued to the EAA, then later to Petersen Aviation. Since then, some 65,000 autogas STCs have been issued, nearly one-half of the entire fleet of piston-engine aircraft. Most new LSA aircraft use engines that have been designed to operate best on autogas, and most next-generation aircraft engines for heavier aircraft are designed to use autogas due to the limited availability and high cost of avgas in many parts of the world.

“Automotive gasoline is approved for use in only a portion of the GA fleet and faces a number of significant issues.”

As noted above, autogas is an FAA approved aviation fuel for at least 70% of the legacy piston engine fleet, essentially 100% of the new LSA fleet, and is the primary fuel for virtually all next-gen spark ignition piston aircraft engines. A portion of these, experimentals using auto engine conversions, are not approved for leaded avgas, and many of the newer aircraft engines TC’d for autogas (especially Rotax) suffer serious maintenance issues as a result of leaded aviation fuels.

“These issues include, but are not limited to, the economic challenge of developing a second fuel infrastructure to serve a limited market, and the growing difficulty of finding fuel not blended with ethanol.”

The infrastructure for autogas in fact has existed for over a century and is enormous compared to that of boutique aviation fuels such as avgas. Some 110,000 retail gas stations sell gasoline in the US today, and these are supplied by tens of thousands of companies whose trucks roll daily by virtually every one of the 3,500 airports that offer avgas. While there are estimated to be fewer than 10 avgas producers in the US today, there are some 1,300 fuel terminals. Avgas represents less than two-tenths of 1% of fuels produced in the U.S., and only 1/20th of the Jet-A production. Autogas is produced in enormous quantities compared to both of the fuels and, as long as there are cars, will be.

Since ethanol may not be pumped in gasoline pipelines, by definition fuel terminals all have ethanol-free fuel for sale. Only when ethanol is mixed with gasoline at these terminals and trucked to gas stations is it adulterated. All of the mandatory E10 states exempt aviation from ethanol mandates, and terminals are generally happy to sell ethanol-free fuel to those who need it for aviation, marine, farming, public safety, and other purposes. There are thousands of fuel transporters in the US (“jobbers”) who will deliver ethanol-free autogas from the terminal to FBOs, sometimes over a distance of several hundred miles if necessary. Most are also willing to make multiple stops at a number of airports and marinas, since these generally prefer less than a full 8000g load.

For those who self-fuel aircraft with autogas, the number of retail locations selling ethanol-free fuel listed at (3,250 on 5/28/2011 and increasing) is now comparable to the number of FBOs listed on selling avgas (3,513 on 5/28/2011 and decreasing). There are thousands of other retail sellers of ethanol-free autogas that are not listed on, a user-maintained web site. The only true impediment to getting more autogas onto airports is the will of airport management and the need for a modestly-sized fuel tank (4,000g is sufficient in most cases), which many airports have among their surplus fuel equipment.

“Congress has mandated the blending of renewable fuels such as ethanol into automotive gasoline. Given the mandated volume of renewable fuels that must be used and the amount of automotive gasoline U.S. drivers consumed last year, virtually all automotive gasoline produced must be blended. And Congress has shown no interest in creating a niche for unblended automotive gas.”

Indeed, with the US poised to reach the so-called “blending wall” in the near future, at which time it will be impossible for fuel producers to absorb the increasing RFS mandates in the EISA 2007 law, these mandates must be modified, just as the EPA was forced to reduce its mandates on the production of cellulosic (non-corn-based) ethanol by a whopping 95% recently when it became clear that previous goals were unachievable. Congress does not need to create a niche for unblended automotive gasoline, since nowhere in EISA 2007 is there a mandate that all ethanol must be used in all fuels. In fact, ethanol-free premium fuel is widely available in many parts of the US, ironically in the states that produce most corn and ethanol, such as Wisconsin, Minnesota, Iowa and Nebraska. For instance, one finds few sellers listed for Nebraska on, simply because it is offered at most gas stations and consumers there have no real need for this listing.

It is important to note that there is no federal mandatory E10 law. EISA 2007 is not a mandatory E10 law, in fact E10 is nowhere mentioned in the act. It was an act intended to increase the production and distribution of E85 and the production of flex-fuel vehicles which are the only cars that can use E85. The only Renewable Fuel defined in the act is E85. E10 is not Renewable Fuel, it is gasoline made to ASTM D4814 with 10% ethanol blended into it. Because of a hard-coded quota table in the act, gasoline producers have been forced to blend ethanol in the only gasoline that sells, E10. The EPA is the sole government agency tasked with overseeing ethanol blending and can with the stroke of a pen prohibit the blending of ethanol in all premium unleaded gasoline. They have been asked to do this by numerous industry representatives that make engines that are negatively effected by ethanol blended gasoline on numerous occasions.

Since there is no federal mandatory E10 law, states, too, have a say in ethanol’s use. Five states have active mandatory E10 laws and many other states have legally limited the amount of ethanol that can be blended into fuel to 10%, and all mandatory E10 states provide exemptions to these laws for aviation and other off-highway applications of fuel. One state, New Hampshire, recently voted on legislation to completely ban the use of corn ethanol in fuels.

The ethanol industry and the legislation that keeps it afloat has been the target of widespread, bipartisan criticism in the past year. Other “alphabet” groups representing the marine, ATV, snowmobile, power tool, etc., industries have banned together to preserve an ethanol-free fuel for the estimated 650 million engines that are harmed by it. The notable exception in this truly broad coalition representing the interests of virtually all Americans are our own aviation organizations.

A vibrant free-market economy depends on multiple choices; the amazing growth in LSA aircraft, with 115 new designs to choose from, is evidence of this. We applaud the GA Avgas Coalition in its effort to find a new high-octane unleaded fuel for the declining minority of aircraft owners who still need it, but urge them to also endorse the other aviation fuel, autogas, an affordable, lead-free alternative that is available in vast quantities and already represents the future aviation “fuel of choice” in many parts of the world.


  1. says

    Joe – “water-contaminated ethanol collecting at the bottom of the fuel tank” is a serious and dangerous problem. The current specifications for fuel ethanol requires it to be anhydrous. The ethanol distillation process only produces about 95% pure ethanol. The other 5% is predominately water. That water is removed by an expensive, complicated chemical process. Then the 99.4+% “fuel” ethanol is added to gasoline at the terminal. But it is usually NOT added to finished legal gasoline generally. It is added to Blendstock for Oxygenate Blending, or BOB. The BOB that is used will have a lower AKI than the finished blend. For regular E10, the BOB is about 84 AKI and by adding 10% ethanol the finished product is 87 AKI regular. Same for premium E10, the BOB is 90 AKI or lower. There will probably be some other chemical tweaks to the BOB to insure that the finished product is legal gasoline. The ethanol mixed in the gasoline will absorb water until it gets the 5%, or so, back that was removed in the final step for making fuel ethanol. Then just about all of the ethanol and all of the water separate into a corrosive blob on the bottom of your tank and the “fuel” that is left will be some unknown hydrocarbon product but it will not be legal gasoline. If you ever see water while sumping the tank of your homebuilt or LSA that you are running E10 in, you have had “phase separation”: and now you have a serious mess to clean up. If you want to understand BOB, see my web site and click on the link to the “List of pertinant E15 waiver comments” and go down to the “New York State Department of Environmental Conservation (Comment attachment)” entry and go to Page 7 which discusses how E10 is made.

  2. William S. Lyons MD says

    Why isn’t the FOE simply challenged on their assertion that the lead in the air from aircraft is toxic to anyone. Clinical lead toxicity for years has been confined to little children ingesting paint and the rare industrial accident. Get ’em to put up or shut up. Recall the big bru ha ha over the snail darter a few years back. Environmentalists like the FOE got our supercollider cancelled over that inconsequential tiny fish. It was alleged that the darter which existed only the stream the collider required would be at risk of extinction. Of course once the collider was cancelled the nothing fish was found all over the Southeast.

  3. says

    Other than water-contaminated ethanol collecting at the bottom of the fuel tank, what is the problem? Doesn’t a competently performed pre-flight eliminate the contaminated ethanol hazard? Someone please tell me where I am wrong!! Please cite good science and well-designed tests.

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