As the FAA's technical testing of unleaded avgas replacements grinds on, owners and manufacturers are still wondering what the approved fuels will look like and whether they will be true drop-ins. At a briefing last month at AirVenture, three members of the FAA Piston Aviation Fuel Initiative offered an overview that warned that the clean drop-in fuel isn't necessarily in sight yet. AVweb was provided with copies of the briefing slides.
This is a companion discussion topic for the original entry at https://www.avweb.com/ownership/100ll-replacement-drop-in-or-not