........yes Sir and the cost related to it would decrease that same fuel saving profit..wouldnt it?
yeah but the question was not about Cost as such. it was about derating/flexing and how that affected fuel consumption.
ie keep the variables the same.. same engines wear same conditions. for a particular flight the fuel consumption would be less ...
It goes without saying that the overall costs would increase with constant use of full rated thrust. That's why most operators reduce takeoff thrust when they can.