Hi Knegel,
>this calculated comparison show a very similar fast 109F4 in low/med alt.
The Me 109F-4 was actually tested. However, it was apparently run at 2700 rpm/1.42 ata, which might not have been cleared all of the time.
Using a slightly slower Me 109F-4 test as basis, the Me 109F-4 running at 2500 rpm/1.35 ata would outrun and outclimb the Spitfire IX with Merlin 61 easily below 7 km, but above that, the Spitfire would be superior.
The Spitfire V would actually hold a slight speed advantage at sea level, breaking even at 2 km. Otherwise, it's completely outclassed by the Me 109F-4.
The Me 109F-4 would be slower than the Fw 190A through the entire altitude range, except around the Fw 190A's gear change altitude. It would of course outclimb the Fw 190A by a generous margin.
Regards,
Henning (HoHun)