I am going to try to explain this quirk using the Aerosoft F-16. I think all can agree that this plane is fairly tough on framerates. I have my fps locked at 35 and a normal flight will start on the ground at about 22 fps. Once I get higher up that increses to 35 in the VC which is absolutely perfect for me. I have always wondered about on the ground though. Obviously it is tougher on frames and the fps will suffer but I am wondering why it is that if I set my fps to lock at 40, rather than 22 it will be about 28-30 on the ground. Why is it that with a higher fps lock I can get higher fps on the ground? You would think if I set the lock to 35 I would still be at 28 on the ground right? Why is it that the ground fps is always about 10 lower than the lock? If I can achieve 30 on the ground with 40 lock, why cant I achieve 30 on the ground with 35 lock? What function in FSX keeps it from doing what would seem logical?