With these 3 aircraft, fuel efficiency may not be the sole issue.
In terms of fuel burn and operating performance, the A380 and 747-8i are expected to be 0.018USG per ASM, and the 777-300ER has a similar fuel burn performance. These fuel burn rates are equal to costs per ASM of about 5.8 US cents. The similarity between the 3 aircraft may be because the A380 and 747-8i benefit from their larger seat counts, but suffer from their relatively inefficient four-engine designs.
Performance/range is also pretty close. With typical airline seating configurations, range performances are 8,250nm for the A380, 7,900nm for the 747-8i, and 8,000nm for the 777-300ER. So all 3 aircraft can operate on most long-haul networks without constraints.
The differentiator is seat capacity and its important consequence for route planning. The A380 and 777-300ER have typical average airline configurations of 482 and 314 seats and 747-8i will probably have 380-430 seats when it gets into service. A lot of the selection criteria will depend on which size suits an airline’s capacity requirements best.
I have got an analogy for the A380 vs 747 debate which comes from the small boat sailing world and the HobieCat range of catamarans. The 747 is like a Hobie 16, which is probably the most popular and widely built/sold small catamaran. It is quite a stretch from sailing to airline economics but here goes.
Take a Hobie 16 (aka B747) and load it up or empty, strong winds or not, rough sea or smooth lake, brand new plane or aged and ragged, it just gets up and goes – every time.
The A380 is like the Hobie 17 – absolute thoroughbred, fast and exciting, but very demanding and finicky. In exactly the right conditions with exactly the right crew, it is a winner.
The Hobie 16 sold in much higher numbers than the Hobie 17, and sold widely across the world. The Hobie 17 was a limited seller. Likewise, for those routes where the A380 fits - long haul and more demand than a 747 can service - it is a winner. But outside that – the economics fall over quickly and the Boeing camp are going to be selling their aircraft. And they have got a great growth path built in - develop the route with a 777 and when that gets too busy, bring in the 747-8i without increasing frequency or slots
