Guys,
The top speed of the Me109G10 in AH is slightly faster than the 451mph being quoted here.
According to my own data, the Me109G10 achieves a top speed of 451.5mph at 22,200ft. (±0.1mph)
However, it doesn't appear to be that fast on the analogue gauge. The performance appears to be spot on, but there is a calibration error in the gauge, possibly because HTC have modeled the fact that aircraft instruments were not that precise.
Hope that helps.
Badboy
Forgot to mention that was with 25% fuel