[Seadog]

Originally Posted by Kurfürst

Agree. In addition the papers David showed specifically mention that ca. 3-4 Bomber Command stations were only to be supplied with 100 octane fuel.

So I guess the million dollar question is who (BC Stations, FC Stations, manufacturers etc.) used and what amount of the fuel, and in what role (operational/non-operational flights, test trials).

Show us evidence for at least one operational 87 octane RAF FC combat sortie during the BofB or admit that you have no evidence to contradict the multiple sources that state 100% 100 octane use by RAF FC during the BofB, such as:

...I do not believe that it is generally recognised how much this
superiority would have been affected had not the decision been
taken to base aircraft engine design on the use of 100-octane
fuel instead of the pre-war standard grade of 87-octane rating.
In fact, it was only a few months before the Battle of Britain
that all fighters were changed over from 87- to 100-octane
fuel, a change which enabled the Rolls-Royce Merlin engine
of that period to be operated at an increased supercharger
pressure which immediately gave an extra 200 h.p. or more.
Subsequent engine developments made possible by the use of
100-octane instead of 87-octane fuel have since permitted a
truly phenomenal increase in the power of the original engine
without any change in its basic size or capacity.
It is very interesting to refer back to the records of serious
discussions which took place only a year or two before the war
when certain authorities expressed the very gravest misgivings
at the proposal to design engines to require a '' theoretical type
of fuel" (i.e., 100 octane), which they feared would not be
available in adequate quantity in time of war, since we were
mainly dependent on America for its supply. Fortunately for
Britain, the majority of those directly concerned took a different
view, and I might quote a rather prophetic statement made by
an Air Ministry official at a Royal Aeronautical Society meeting
in February, 1937, who, in referring to the advent of
100 octane, said: " Let there be no doubt, however, that
petroleum technologists and fuel research workers now have
the opportunity to provide by their efforts an advance in aircraft
engine development, with its effect on air power, which
the engine designer by himself cannot hope to offer by any
other means."
May I conclude by also quoting a reply reported to have
been made recently in the U.S.A. by Mr. Geoffrey Lloyd, M.P.,
Joint Parliamentary Secretary to the Ministry of Fuel and
Power, in answer to the question: " Do you think 100 octane
was the deciding factor in the Battle of Britain in 1940 ? "
To which Mr. Lloyd replied: " I think we would not have won
the Battle of Britain without 100 octane—but we DID have
the 100 octane."
Nevertheless, let us not forget that between the fuel and the
airscrew there are also many other links in the chain, any one
of which, had it failed, could have vitally affected the issue,
while all the technical superiority in the world would, of course,
have been of no avail at all without the efficient training, skill,
and courage in combat of the Battle of Britain pilots.

Flight Magazine, Jan 06 1944
http://www.flightglobal.com/pdfarchi...0-%200044.html