Paul, thank you for pointing out the fallacy that ASTM somehow guarantees a “proper” avgas while GAMI’s STC is witchcraft, not worthy of the flying public’s trust. As you point out, D910 does not mean all producers create an identical fuel, just one that meets a consistent specification. None of the major refiners will tell you exactly what ingredients are in their fuel, just that it meets the D910 spec. How is this any different than GAMI’s proprietary additive package that has been well tested to meet the various FAA fuel requirements? Several years ago, when PAFI 1.0 was in full swing, I had the opportunity to sit at a dinner table next to George Braley. I asked him why GAMI did not enter the PAFI competition. He said that, based on how the FAA structured the process, it was virtually guaranteed to fail in producing a useful result and he felt that going it alone gave him more freedom to test and make changes to arrive at a useful end product. With PAFI, the formulation you came in with could not be changed, which defeats the purpose of a science-based process. I agree with you that the not-invented-here syndrome has played a part in the FAA’s continual obstruction of GAMI’s process, and EAGLE is just another roadblock set up in the hopes that some magic unleaded avgas will appear from the usual suspects and save the day. Maybe it will, but if (when) the EPA delivers a finding of endangerment, it is possible that the one producer of TEL then calls it quits. In that case we, and the FAA, will be in a real pickle without GAMI’s UL100. As for EAA’s concern about homebuilders not having access to an STC, I suspect GAMI would be willing to sell them the engine STC, providing they are using a Lycoming or Continental engine. After all, both manufacturers have said that G100UL will work in any of their spark ignition engines now, or previously, in production. If the builders are using another engine, they are probably using mogas anyway.