ACMS
Thanks for your reply.
However, do you really compared fuel burn on this long trips using CIs around 20 and CIs aroung 180 and M.84? Take into account that these fuel burns comparisons will only make sense provided all other variables comes very close (TOW, taxi times, vectoring/holding, average winds and temperature, etc).
I sincerely doubt any airline has done it and got the real numbers. Ops geniuses normaly rely on manufacturer FMC predictions.
They may have a surprise in case decide building a data base, with a significant number of flights going "fast" (M.84 or CI 180) and the others going on M.83 or CIs around 20.
As far as the data I built reveals, the only significant difference is flight time.
The bottom line: in effect, will be more expensive to go slow, putting into the equation time related costs.