I  realize this is off topic as well, but perhaps of higher interest.
It  pertains to testing of 94UL in a  Continental.

http://www.flyingmag.com/piloting/1865/flying-a-big-bore-engine-without-the-
lead.html

One  comment in the article near the end I would question is this one:

/"Of  course, because 94UL is lower in octane than 100LL, its potential
energy  will be lower across the board, regardless of whose engine the
future fuel  is being used to power."/

High Octane provides a slower burn rate, but  caloric value should be the
same regardless of Octane number.
What is  the general consensus on that?

Rolf




Rolf,
You are correct, within limits BTUs available are, if anything, higher on
94 UL. Often octane boosters like lead only displace some of the molecules.
If  your engine has detonation because of low octane you won't be able to
use the  additional power though. Most engines get the best milage using the
lowest  octane fuel that they can run safely.
Bill Jepson