The GAfuels Blog is written by two private pilots concerned about the future availability of fuels for piston-engine aircraft: Dean Billing, Sisters, Ore., an expert on autogas and ethanol, and Kent Misegades, Cary, N.C., an aerospace engineer and aviation journalist.
Hjelmco Oil of Sollentuna, Sweden, has provided 100LL and 91/96UL unleaded avgas for over two decades. It recently documented its research concerning unleaded 100-octane fuels making use of ETBE as an anti-knocking component. Hjelmo has provided details on similar work performed at Cessna Aircraft, including Cessna’s rigorous in-house fuel testing facility.
A CD-ROM recording of the Cesar Gonzales forum can be ordered here: http://www.forums4.us/fl2010.php
Look for Forum: 144 Path To Unleaded UL AVGAS Cesar Gonzalez
This was an excellent forum. There is an answer to a question at the end of the talk that was worth the price of admission.