Why the controversy about unleaded avgas?

Ben Visser is an aviation fuels and lubricants expert who spent 33 years with Shell Oil. He has been a private pilot since 1985.

The most common question I get concerning unleaded avgas is, “why all of the controversy?”

In an effort to try to answer that question, I would like to explain the players and what their main concerns are.

The player with the biggest stake in this is the engine manufacturers. They are being asked to build and guarantee the durability of engines that operate on fuels available in the future. The only problem is no one knows what the future fuels will be. This is like being asked to write a cookbook but not knowing what ingredients will be available. In addition, they are being asked to modify all existing aircraft to run on this unknown fuel. Now you throw in our liability laws and a few thousand hungry attorneys, and you can start to see they have a problem. There are several possible solutions, like diesel engines or modified spark ignition engines that run on lower octane fuels. But none of these solutions will cover everyone. We also have engine rebuilders, especially ones that work on radial or “orphan” engines who are even further up the same creek.

The other big player is the oil companies. These are the people with really deep pockets. And guess what? They intend to keep those deep pockets. Avgas is only a few tenths of 1% of the fuel business. If the oil companies feel that they cannot make a profit from a new fuel or if the new fuel represents a high liability risk, they simply will not participate. We must remember that oil companies have the expertise and facilities to produce, handle, and distribute avgas safely and guarantee it, so it is a little like the playground where the kid with the ball makes the rules.

Next we have the people who produce specialty or boutique fuels. They are running around buying special fuel components for $60 a gallon and telling everyone that they can produce this stuff for half the cost of current avgas. Now I do not doubt that they can produce a product. My concern is the cost, where will it be made, what unknown problems will be found in the field, and who will guarantee the performance.

And then we have the government agencies that are caught in the middle. The EPA is being lobbied by  environmentalist groups that heard if you eat lead-based paint it can be a health hazard so therefore want it removed from avgas, even if there is no health risk, may risk the lives of a lot of people, and could ruin an industry. But who cares if it makes them feel good?

The EPA must also deal with the FAA, who must deal with the real world consequences of lead removal. And both must deal with the politicians. I was trying to find something to say about this group that was fit to print, but so far I don’t have a thing. I will get back to you on that if I come up with something.

We also have the news media and the alphabet groups. The aviation news media has been reporting on the decline of general aviation so long that we are looking for anything different to report on. Just look at me — I used to have to think about something intelligent to write about each month. Now I just read all of the junk written about unleaded fuels and get so disgusted that new columns just roll out.

Meanwhile, the alphabet groups are running around saying, “we solved the problem, just look at us, we solved the problem.” That is like the local weatherman who reported that if it does not rain it will be a dry year, and then demanded a raise because his forecast was right.

Finally, we have the flying public. On the positive side, they get to watch this soap opera unfold. On the negative side, they have to gamble on what is the best course of action for their plane. It’s kind of like learning to do a high wire act without a net.

You can contact Ben Visser at Visser@GeneralAviationNews.com.


  1. says

    I work for a small business that, among other things, designs fuel farms for FBO’s and corporate aviation departments. We have been following this topic closely as it directily affects our business. I have blogged on it several times on our website and just posted a link to your article on our company Facebook page. The bureaucrats and the alphabets are definitely making this harder than it needs to be, but isn’t that always the case?

  2. Ben says

    Here’s a crazy idea, why not just leave everything as it currently is. I’d like to see a study with real science behind it that says there is a health risk with 100LL after it goes through the combustion process…

  3. says

    Ben, you’re exactly right. The partial solution for non-turbo engines only raises the cost to the rest of us who have depended for years on the safety and efficiency afforded by factory turbocharged engines.

  4. says

    Good morning Ben. You’ve got this just about right. We are dealing with a chronic lack of leadership. It’s the biggest issue ever faced by the GA community and it is ill-prepared to deal with it.

    The alphabets are bureaucracies which are capable of giving us a nice history lesson, are claiming to have our “backs and “not to worry”. This is not helpful.

    The FAA seems not up to the task. They correctly claim it is not up to them to specify a fuel — only to certify what others present to them. No leadership there. They punt to ASTM.

    ASTM is a volunteer, consensual seeking body which meets twice a year and is tasked to identify, approve and “hold” standards and specs. The members have competing agenda — and the whole thing is completely dominated by the refiners. Consensus is achieved only when noboby’s business interests are threatened. So little motivation and certainly no leadership there either.

    So it’s up to the entreprenuers like Swift and GAMI to get things going. But it takes $$ — lots of it — and these guys are at the complete mercy of these other bodies. Arbitrariness and unnecessary uncertainty reign supreme with the process they face. Even though the prize might be quite rich, who will fund in such a climate?

    Have you read the draft for AC20-24C — supposed to provide new guidance to the industry from the FAA re: how to get fuels and lubricants certified? A “passing the buck” exercise by the FAA — an uncertainty accelerant!! Yipes!!

  5. says

    Well put, Ben. We in the U.S. however tend to think of engines still as monochromatic: Continental or Lycoming. If one is dealing with existing engines, that makes sense. As 70%-80% of all the airplanes powered by these engines may run on 91 octane ethanol-free Mogas, we already have an unleaded avgas available. The best part is, it is the same fuel as used in hundreds of millions of cars and other vehicles. Aviation already suffers from the high cost of small production volumes, so why not at least piggy back on vehicle fuel to lower costs? All we need to do is convince the EPA they would be making a brilliant move by banning ethanol in premium gas. Who cares if they then take credit for lowering lead pollution by nearly 200 tons / year, and lowering the cost of aviation for the majority of pilots? That does not solve the problem of 100LL, but it sure gets us a long way there and at a minimal cost to all.

    Thinking longer term, we have a larger array of aircraft engine options in the pipelines, and nearly all of these engines are designed to operate best on Mogas, not 100LL. Rotax and Jabiru are just two examples. There are others, like Belgium’s ULPower, who is working on a new family of engines up to 130HP. There are now two twin-Rotax airplanes on the market (Tecnam P2006T and DynAero TwinR)
    with performance exceeding many legacy twins but burning under 9GPH total. Again, the ideal fuel for these four-seaters is premium Mogas, provided we keep the ethanol out.

    For legacy engines, Mogas is ideal, it’s legal, safe, and affordable. For future engines, Mogas is the recommended fuel.

    Instead of focusing solely on a diminishing part of the piston-engine fleet, why not put at least as much effort into keeping ethanol out of premium gasoline and getting low-cost self-service Mogas pumps on our airfields?

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