Weeks after the FAA approved an STC on GAMI’s G100UL unleaded 100-octane avgas for virtually all piston gasoline engines, the EPA has formally proposed a finding of endangerment on 100LL, a pivotal step toward banning the blue fuel. EPA Administrator Michael Regan signed the proposal on Oct. 7 and is submitting it for publication in … Continue reading EPA Proposes 100LL Endangerment Finding