Official Bf 109E specifications, guaranteed by manufacturer within +/- 5%. All Bf 109E accepted by the Luftwaffe had to fulfill these specifications for acceptions within the above limits.
http://www.kurfurst.org/Performance_...chreibung.html
In short, our Bf 109Es are 40 km/h short of speed at low altitudes. FM bugs so far prevented to verify if they can reach 570 at altitude (did not test with latest patch. No TAS indicator either)
Spitliarperformance site as usual reports only speed at 30-min ratings, not maximum outputs.