Wilbus, this excerpt ist from Alfred Price "FW190 in Combat" page 46, in which he quotes britisch tests from the FAE.
And the speed attained in the dive was 580 mph TAS (934 km/h) at 16k not 550 mph TAS.
LOL maybe HTC has confused the tiffies dive characteristics with those of the FW190, as the tiffie manages in AH what the real FW190 was capable of in WW2 and the AH FW190 is limited in the way the WW2 tiffie was.