The company behind the only candidate left in the FAA-driven Piston Aviation Fuel Initiative process to create a high-octane unleaded replacement for 100LL says it's impossible, according to Aviation Week. “There is no such thing as a drop-in unleaded fuel to replace 100 [LL],” Dan Pourreau, business development manager with LyondellBasel Industries, told the publication “We thought initially we were going to be able to do that, but we discovered we can’t do that either.” Pourreau said paper and technical modifications will be required on some engines to allow them to run safely on unleaded fuel. The LyondellBasell fuel UL100E is being evaluated through the congressionally mandated PAFI process at the FAA's test facility in New Jersey.
This is a companion discussion topic for the original entry at https://www.avweb.com/aviation-news/100ll-drop-in-replacement-impossible-says-pafi-candidate