Does anyone have fuel burn data for the 380 & 748? I know that a 744 burns around 10 tonnes / hr (obviously it will vary according to various factors such as weight). The 77W (773 ER) burns 20 - 25% less and has roughly the same capacity (slightly less passenger space, more bellyhold capacity). It was reported in Flight that the Lufhansa reports that a 748 has 15% more capacity than a 744 and burns roughly the same amount of fuel. That would make it less fuel efficient that a 77W. The 380 is I believe less efficient than the 787 and possibly 77W. That said the VC10 was less efficient than the 707 but its greater passenger appeal made up for this (at least until oil prices quintupled in 1974).
Cathay reported that fuel accounted for 50% of all operating costs a couple of years ago. OK that included hedging losses but oil was not at its peak for the whole year. At $3.60 / US gallon a 747 will cost $12,000 / hr or $50m p.a. Replacing one with a 77W will save around $10m p.a. Replacing a 744 as it becomes due for D-check is likely to be highly cost effective anf explains why Airbus & Boeing have bouyant order books. Of course if jet fuel prices drop the economics will change. It has been suggested that the a new generation of effectively hybrid jet / props would have been developed fifteen years ago if fuel prices were where they are today at the time but it didn't make sense. It also explains why a large number of old 727 weren't replaced with 757s at the time.
Back to my original point, does anyone have any data as to fuel cost per seat mile (or square metre of cabin space or whatever is the best way to define it) for various types of jet?