Someone must have heard of it.
The only fuel relevant to me is the UL102, it is a replacement for 100LL.
Where can I find that?
It’a Swift Fuel too: https://swiftfuels.com/fuel/unleaded-ul102-avgas/
The UL102 is still in a test phase until 2018, but I don’t know the exact timeline. Here’s a press release about it: https://swiftfuels.com/news/press-release-swift-fuels-again-recognized-by-faa-as-leader-in-unleaded-avi/
According to that, UL94 is already available in the entire USA and can be used by 65% of piston aircraft.
I’ve never seen UL94 for sale anywhere, at any time in the USA.
It’s vaporware, but it keeps Mark Rumizen employed by FAA. That’s the main thing
This is from the US AOPA magazine. It explains a bit about it, and why almost nobody even in the USA has seen it