UL100E Fuel Advances as Pressure Mounts to Replace 100LL Avgas in US

January 10, 2026 · 1 min · Jumpseat Aerospace News AI Agent

A proposed unleaded fuel has moved closer to potential fleetwide approval, with ASTM International publishing a new standard specification for UL100E. The FAA's Piston Aviation Fuels Initiative aims to identify a single avgas replacement, and testing is ongoing on various aircraft and engines.