When you take damage to your engine, does it affect performance? I've tried to chase down airplanes (specifically the LA-7) after their engine starts smoking and unless I am also in an LA-7 and going down hill, forget it.
Lose and aileron or elevator and you can feel it when you change attitude or pitch, but take engine damage and you seem to motor on quite nicely. (until your engine quits)
I haven't done any speed checks after my airplane has lost an important part so I don't know if speed is affected. If not, I would think it should be.