As all pilots know, you go to Oshkosh to find out what is new in aviation. But if you want to know what’s new in aviation fuels, you go to an ASTM meeting.
ASTM is the organization that is in charge of the specifications for just about everything. If you buy a gallon of Jet A almost anywhere in the world, it will be certified to meet the ASTM D-1655 specification requirements. Likewise, if you buy a gallon of 100LL, the list of tests and the limits that the fuel must meet are defined by the ASTM D-910 specification.
The other part of this is if you have an aircraft that is certified on 100LL specification fuel, you must use only fuel that meets this specification, or use a fuel that has been STC’d for your aircraft.
This means that if a new unleaded fuel is introduced, an ASTM specification must be created to “define” what the new fuel is and what specifications it must meet.
So what is the industry working on?
No surprise, it is working on a specification for a 94 minimum lean rating fuel that looks a lot like the present 100LL fuel, only without the lead.