In my January column I wrote that not all 100 octane fuels are the same. Now it has been reported that the 100UL avgas program has been more or less put on hold. The reasons given were technical problems and the change in administrations in Washington.
This begs the questions: “Why did the program go on in the first place?” and “Why would big oil companies put so much money into a program that may not go anywhere?”
The history of 100UL starts in the 1990s when there were several lawsuits brought in several West Coast states. The EPA started to outlaw 100LL, but the FAA stopped that on safety reasons. The compromise was that the FAA would work on a safe way to “get the lead out.” This started a long process of committees working to develop a 100 motor octane unleaded avgas replacement for 100LL.
I attended several of these meetings before retiring and they were interesting. At one of the meeting in Oshkosh, I asked about exhaust valve recession problems with unleaded fuel and the problem of lead bonus, in which leaded fuels offer significantly higher anti-knock properties than unleaded fuels of the same octane.
On the first question both engine manufacturers jumped up and claimed that valve recession was of no concern because they had hardened seats and had not seen any problems with people using unleaded mogas.
On the second question the response was the belief that they were sure that all that was needed to satisfy the entire fleet was a 100 octane unleaded fuel.
The next day I questioned several aircraft engine rebuilders and technical representatives from the engine manufacturers. They all said they had seen numerous cases of valve recession when unleaded mogas was used.
But the program went on, first with numerous candidates. This was narrowed down to five, then three candidates for further evaluation. The final three were two fuels from Swift and one from Shell. Then Swift dropped out and the program stalled.
The question about why an oil company would invest millions in a product that was not approved goes to how big companies operate. I am sure that a manager saw the unleaded fuel debate and figured this has got to be a great opportunity. The logic here is that if 100LL is outlawed, then the company with a qualified 100 unleaded avgas would have a gold mine and the manager would get a big promotion.
The liability question, the valve problem, the possible knock problems, etc., would be of no concern if the company made money. Besides, at the time it sounded like the EPA would outlaw 100LL in the very near future.
But things change and now the future of 100UL is in question. So what will happen next?
I would guess that not much will change nationally in the next two years and maybe six years, depending on the 2020 election. There is a chance that some states will try to outlaw 100LL, but without an approved 100UL product that could be a problem.
However, many state government officials do not let facts and logic enter into their thinking and the legislative process because it slows business down way too much.