Teledyne Continental Motors has done a number of tests with unleaded gasoline that is supposed to be made to the ASTM spec for 94 UL avgas.
There have been several PR releases about these tests, including a report at EAA.org
Apparently the tests are a complete success and Continental is ready to certify all of its engines for the new unleaded avgas.
The funny thing is that Continental also says on its website not to use unleaded gasoline in its engines.
... read the rest of Continental sends mixed messages on unleaded fuels (586 words)