Originally Posted by
PJZajkowski
From the SWIFT website describing UL94:
"This proprietary unleaded fuel formulation is a blend of hydrocarbons designed to meet the fuel specification standards of ASTM D7592, D7547, and D4814. This fuel is FAA-certified for use in up to 65% of the US piston fleet; up to 100,000 aircraft are already certified to use the fuel based upon existing Type Certificates and/or Autogas STC's. An additional 25,000+ aircraft, those whose engines are rated for minimum Grade 91/96 Avgas, are eligible to purchase an FAA Supplemental Type Certificate (STC) for the use of Unleaded UL94 Avgas."