After a little research, it appears:
1) Swift's proprietary 94UL is being sold at a number of airports around the country, is the same weight as 100LL, but requires an STC from Swift to be used in a DA40-180 Lycoming IO-360. (Swift markets this 94UL STC with the implied promise that the STC holder will receive the future Swift 100UL STC for free.)
2) GAMI has worked with the FAA on their proprietary G100UL, gotten essentially all the approvals, but FAA headquarters is 'dragging its feet'* on issuing the final documents. (*-the most politically correct way I could phrase this.)
3) Swift also has a 100UL effort, but their FAQ indicates that it is "currently undergoing testing and certification with the FAA."
4) Both GAMI and Swift's 100UL products would be proprietary, but manufactured and distributed by license holders.
5) Both GAMI and Swift's 100UL products would be drop-in replacements for 100LL, meaning an aircraft or fuel storage 'container' could hold either 100LL, or 100UL, or any combination of both. (Note this is different from Swift's UL94. Their FAQ states: "FBO’s who sell 100LL to higher compression aircraft must keep UL94 in separate storage tanks.")
6) Both GAMI and Swift's 100UL products would weigh more than 100LL. 6.3 lbs./gal for G100UL vs. 6.0 lbs./gal for 100LL.
7) Both GAMI and Swift have commented to varying degrees on the FAA-managed PAFI fuel test program.
GAMI has had a Cirrus aircraft using their G100UL formulation for over 10 years. (I can't recall if it was an SR20 or SR22, but honestly, does it matter to us.
)
Questions:
- With the Swift 94UL STC it appears this approves the engine to consume Swift's 94UL, but how do parts manufacturers, Diamond, the FAA, pilots, and most importantly insurance companies feel about this fuel being 'used' in all other parts of the fuel/power system? Are we going to play the "Well, the most important thing is the engine, so since that's covered we'll risk the rest." game?
- Will the 100UL fuels require an STC for each aircraft, complete with stickers and POH/log-inserts, or by some regulatory magic will it just require the fuel pump to have paperwork on file?
- Are we potentially looking at a future where multiple differently-formulated 100UL fuels will be sold by different distributors across America?
ps: For the record, I will be one of the first to cheer when we finally get TEL out of our fuel.