I think so, in most A/C for every 5K you land with you burned at least 1-1.5K carrying it there on an average flight. Lots of variables, so "your milage will vary". But, if one was to extrapolate it out across every sortie the company flies every day/night, it becomes a
VERY large number very quickly. So for a company like FDX it might be like buying and burning an extra 150K of Jet-A a day, every day. Assuming 2000 sorties/day.
Now for the "math in public part, 150K x 365= 54,750K /6.8lbs/gal = 8,054,750 gallons per year! At what cost per gallon? Will that be Cash, Credit, Debit, or Profit Sharing?
Remember, that's just 5k extra at arrival per sortie.... but it has consequenses (sp), don't get me wrong, when I think I need the gas, I put in every drop I think I need, for all the reasons stated prior in the thread, right to the point I reach max gross, and then the freight starts coming off the jet.
It's all a calculated risk/reward, and the folks making the calculations are not in the jet like you and I are.
Just make your own decision concerning fuel loads, just be prepared to defend your decision.