It seems to be more complex than I have expected.
I tested all combinations between old and new .cfg and .air files with full cargo (30000 lbs) and 100% fuel in all tanks.
With Climbing rate at 1500 ft/min climbing speed reached at 145 kts in all combinations.
Cruising speed at 10000 ft reached to 200 kts.
But I think there are influences at climbing phase if you are using pitch from autopilot panel or trim.
Using pitch it is possible to run in stall.
Another observation I found that .cfg-file will be changed after each flight. (seen at change of date/time of the file)