B Carey, FAA releases draft plan for Avgas transition, Aviation Week Network, 12 January 2026

In US, the FAA seeks public comment on its plan for more general aviation aircraft and helicopters to use unleaded Avgas by 2027, and US-wide by 2030.   The three potential candidates comprise GAMI G100UL, LyondellBasell UL100E plus Swift Fuels100R, and any effects of intermixing are of current concern.   In US during 2023, some 180 million USG of Avgas were consumed.