I found out if you take the old fuel load value (example 5050) and you want to change it for good use with new RPM data, you can use a simple formula. 5050 / 15500 (old Gp2 revs) x 17800 (my new Gp2 2000 revs). This makes a value of: 5799. This is a perfect value, fuel consumption is O.K. now. This works for several tracks, i tested it already.
Maybe it's an idea to take this value and formula within your physics editor.
