Try reading it again.
"Full information on fuel grading is given in a recent R.Ae.S. Paper by Air Commodore F. R. Banks.*"
"•"The Importance of Power Unit Development'' by Air Cdre. F. R. Banks. Journal of the R.Ae.S., April, 1945."
So the article was based on a paper written by Banks and therefore no misinterpretation or changes from the original paper could have occured?
Did the paper Banks presented even mention the fuel blend used in the Lion engine?
The Fuel blend used in the Lion was not a lot different than the blend first used by Banks in the "R"engine (a lot less lead used in the "R") and the idea that you could use straight run gasoline of around 93PN (after the addition of the lead) in a supercharged engine with 10-1 compression ratio is a little hard to believe.
This was in the early days of lead use and it took a while to realize that the use of lead did not give linier results.
By the late 30s they realized that with a straight run petrol of about 76-77 octane adding 1 cc lead raised it to about 84 octane, 2cc gave just under 87 octane, 3cc gave 87-88 and 4cc gave 90 octane. Using large amount of lead (anything over about 6cc) gave very little in return.
I do like the comparison of an engine running at lean mixture at medium/low cruise power to an engine supposedly going full tilt.
I don't suppose those racers might have throttled back at times? Like going around the turns?
View attachment 490121
On the last lap the only two planes in the air were the British ones.