Performance of the Fw 190A on the Deck?

[Franek Grabowski]

Bill, it is obvious that P-51B/C was aerodynamically slightly different than D/K. I cannot say for sure, but I suppose there might have been some other slight differrencies, eg. in props. That said, drop of maximum speed was the result of several minor changes, and not only one factor. Still, 10 mph is within marigin for error and may purely depend on quality of factory fresh aircraft, not to mention worn out airframes.
Overall, the point that Graham tries to make is not that the weight is unimportant. He just merely points out, that differencies of weight caused by fuel consumption are mariginal for aircraft performance in horizontal flight. It does matter in vertical manouvers, though. This is obvious for anyone, who ever attempted to calculate such things, just as it is obvious, that adding a few pounds of putty and lacquer will increase the horizontal speed!