Each individual should be free to decide for themself.
GAMI has done extensive testing on detonation, especially compared to 100LL.
GAMI’s long AML for engines includes the R-2800 engine used on many military airplanes and the DC-6B airliner. (It came in many power levels and design vintages.)
I understand that some people derate the engine to use lower octane fuel (with 100/130 hard to find and 130/145 perhaps near impossible).
Wikipedia quotes Lycoming as saying that special oil is needed with unleaded avgas, via an additive or some brands of oil, to properly lubricate the valve train.
Wikipedia notes other potential UL avgas offerings including Swift’s, but is mostly out of date on them. It refers to a new ASTM specification for unleaded Avgas (ASTM D7719).
Swift abandoned the STC path and went with the PAFI program, though its website is confusing. It has STC licenses on sale for $100 pr airfram-engine combination. But web stie is confusing between UL94 and 100UL.
You got that backwards. Swift was in the original PAFI and bailed on it in favor of what appears to be an STC application. They haven’t stated that plainly. Their UL94 is a ASTM D7719 spec fuel. The spec covers high aromatic fuels broadly. You still need STCs to use it, or blanket approval from the engine manufacturer.
The hurdle is that fuel distributors don’t want to sell a third fuel. Without the blanket STC, only a few customers will use it. Most airports only have facilities to dispense Jet A and Avgas. Adding temporary support for a third fuel is considered too expensive. If the entire piston fleet can switch at once, then 100LL can be easily replaced.
Distribution is not FAA’s problem; only safety is within FAA’s wheelhouse. FAA should immediately approve GAMI’s STC package or specify the safety reason for continuing to withhold approval. The market will determine distribution.
The problem I see with the STC route is gaining the on airport infrastructure to support the sale of a new fuel. FBOs will not invest in the infrastructure until there is a crystal clear path and even then they may resist spending the money (ie. wait on a path to apply for a government grant that currently doesn’t exist). Because of this I think an STC for an alternative fuel is a bridge to no-where.
I wish I had been at AirVenture to attend this forum. I am hoping there was a video recording capturing it. Does anyone have a link to view it after the fact?
To clarify; the “questions, not comments” rule was for everyone, not singling out Braly. That stipulation was what he cited when I asked him later on why he did not take the microphone during the Q&A.
And FYI, I was sure to have Paul review the copy before it was posted, for exactly the reason you mentioned - “Paul Bertorelli, who has followed this debacle for years.”
Still not hearing WHY E0 mogas, whatever octane, cannot work. It only took auto industry a couple years to get rid of lead. It’s taken, so far, over 40 YEARS, and the FAA still has nothing but hype and hyperbole.