Quote Originally Posted by PaulMillner View Post
Let's see... it says, "91 Octane Minimum"

But then... note the thread title, "Piper completes flight tests of Archer fueld by 93 Octane"

It seems we have a disconnect here...

Of course, in parts of the mountanous west, even 91 UL is difficult to find... RUL is 85... MUL is 87, PUL is 89...

Paul, Lycoming requires 93 aki minimum for autogas. That is probably why Piper used 93. But Petersen's STCs require 91. Disconnect? Mebbe, but that might be why. Lycoming SI 1070S.