Unleaded avgas: You’d have to be insane to try to develop it

I received numerous comments about my recent article on the bonehead editorial in another magazine that called for the removal of brain-dumbing lead from avgas (Misguided public opinion could end avgas, April 20 issue). One of the notes was from a Dr. Lyons concerning the futility of trying to replace leaded avgas. He also pointed out that the EPA is considering reintroducing lead in auto gas.


I received numerous comments about my recent article on the bonehead editorial in another magazine that called for the removal of brain-dumbing lead from avgas (Misguided public opinion could end avgas, April 20 issue). One of the notes was from a Dr. Lyons concerning the futility of trying to replace leaded avgas. He also pointed out that the EPA is considering reintroducing lead in auto gas.

In my opinion, the EPA thing is just a release to make it look like the government is doing something about the energy shortage. If lead were re-introduced, the yield of most refineries would be increased because less energy would be needed to meet the octane needs of the current unleaded gasoline pool. The problem is that the only vehicles that could use it would be cars produced before 1975. Since the fuel could not be transported by pipeline, it would take more energy and cost more to transport it than one would save in the refining process. Illegitimus non carburundum.

Now, let us talk about the futility of replacing 100LL with an unleaded product. This is truly one of those mixed emotion questions. On one hand, the industry has spent millions of dollars trying to find a perfect solution to a problem that does not have a perfect solution. On the other hand, the controversy has sparked a great deal of interest and new thinking in the industry. The development of an unleaded avgas is limited by our liability laws and economic reality. If one analyzed all of the knowledge about the fuel requirements for internal combustion engines being used in general aviation today and the unleaded fuel components available, one would come to the conclusion that it is impossible to produce an unleaded fuel economically that will meet or exceed all of the performance parameters of our current 100LL (with no negative side effects). Once you accept that premise, you then must conclude that a significant percentage of the existing fleet will not operate without problems on an unleaded fuel without some engine modifications.

This leads us to two deal-killing problems. First, almost no one will buy an unleaded fuel that cost more but offers less performance and possible engine problems unless they are forced too ? i.e., read unless the current 100LL is discontinued. Second, who will offer modifications for all of the various aircraft that are in the current fleet and then guarantee that the engines will operate trouble-free?

If you are a relatively sane person, would you consider working on a project that has two impossible problems facing it? Are we really hoping that someone will make a world-class scientific break-through to save our industry? Break-throughs usually cost a lot of money and general aviation is a very small industry.

So why bother? Shouldn’t we just forget about it and spend the small amount of development money available in our industry on more important areas that actually have a chance of working?

In my next column, I will look at the positives of the controversy and then make some SWAGs about the future.

Ben Visser is an aviation fuels and lubricants expert who spent 33 years with Shell Oil. He has been a private pilot since 1985. You can contact him at Visser@GeneralAviationNews.com.

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