I use the F-14 because those figures are the only ones which I know to be definitely true with the loads given, as opposed to other figures for other planes. Besides, with a max take off weight of 30000 kg, that is closer to the F-14 max takeoff weight than the F-15E. As I said, even if you add 1000 L to the 6500 L figure, or even more – let’s say it now has 8000L. How are you going to get twice the range with a heavier payload? This is not a slight increase, this is a MASSIVE increase in performance that isn’t likely to be achieved on a Spey type engine, even with some weight loss and fuel gain (which at most brings it’s empty weight down to 15000kg and fuel load up to 8000L).

I’m questioning F-14, because I’m not sure how having swept wings will affect the fuel efficiency, but then again, I don’t know enough about the aerodynamics to judge one way or another. Anyway, I’m out of this JH-7 issue as far as this thread is concerned.