There is no doubt that there is some sort of demonstrating our superiority ooze about these turn radii graphs... but regardless the figures seem to be about right.
It is entirely another question why this so called superiority is given so much importance. Even the graph shows that the turn radii difference between the Hurri and the 109 was about 200 feet, or about 60 meters. Even the span of these aircraft was 11-12 meters, and actually that's about the distance a 109 wingman kept from his leader... or even less. So what's all the fuss about it?
BTW the figures are rather similiar to what Morgan and Morris came up with in 1940 (for 12k feet - both figures are more of an educated estimate, not trials):
http://kurfurst.org/Tactical_trials/...ls/Morgan.html
