Originally Posted by
hamster3null
At normal cruise altitude and accounting for takeoff, though without correction for below-average # of pax.
Sure, dropping to 12000' would lower the range, but we don't know the exact descent profile and we don't know how long it stayed there. It would certainly not last full 7.5 fours at 12000' all the way through. (I can't find data on fuel burn at 12000' for any large aircraft, but even going down to 25000' would cut maximum range by ~10%)
See my previous answer, even 25k does not correlate with the last radar position.
Then there was a suggestion to increase range but flying more slowly and reducing fuel burn. It does not work that way. There are 3 speed ranges:
Maximum - gets there fastest but uses lots of fuel.
Range - goes furthest for the fuel burn.
Endurance - flies for longest time but not as far.
To fly the farthest is follows it would need to fly at best speed which is Range speed and cruise climb.