Not only has the number 20% savings been floated out for consumption, but so has a 30% savings on maintenance cost. However, for anyone to figure out what derives a maintenance number is harder to come by, unless you have statistical data from many operations, and over many years under various conditions of operation. It is a nebulous number to corner, and define coming from an outside analysts point of view, without having inside data from a broad scoping operation.
So one must trust Boeing's research number of 30% maintenance savings for the 787, over its other conventional suite of aircraft in operation. Compare operations costs with today's fleets in the airlines when buying a 787.
Now fuel costs are a more direct number one should consider when viewing the scope of advantages for the new 787 design. Flying from Japan to Germany is a substantial distance. It is 5,880 miles one way. A conventional Jet will burn x gallons to get to Frankfurt from Haneda Airport, Japan and then returning with using approximately the same amount of fuel. A 20% savings means not loading the airplane with not so many gallons for its weight,fuel and weather conditions it faces. The Airline will calculate passenger weight, and fuel weight when determining exactly how many gallons needed to safely carry the aircraft to its destination. As of November 2, 2012, jet fuel cost around $2.96.9 a gallon. Even though the price per gallon has decreased a little, it still is a major cost risk for airlines. The 787 mitigates that risk over its competition with the 787. If older aircraft raises its ticket prices from needing to burn more expensive fuel, and compounds it further by carrying additional fuel weight on long hauls, then the 787 is a windfall for those airlines having the 787 fleet.
That very concept is not even noticed by passengers as they sleep on a long haul flight. But attention will be made by a passenger when buying a ticket for $75.00 dollars less and seated on a newer aircraft.
The total fuel capacity for the 787-8 is 33,528 U.S.
gallons (126,917 liters). At 33,528 gallons a full load will cost $99, 544.00 at current fuel prices. However, ANA will not fill the 787 with a full load of fuel on this flight. Even when even loading the 787 with a full load of passengers, crew and luggage.
A-330 Maximum Range Fully Loaded is 10,830 km (5,850 nmi) fuel capacity is 97,530 L (25,760 US gal).
A-330 Maximum Range fully fueled is 12,040 km (6,500 nmi) with a light load.
What this means is that a fully loaded A-330 will not make the 5880 miles safely, even with a guarantee that no head winds will occur. They would have to lighten the load further with a carry-on luggage only configuration. The A-330 will have to segment the journey rather than non stop it.
A 787-9 would do do just fine with 280 passengers. The 787-10 still needs further program refinements before actual numbers on fuel economy are factored.
A final thought on this example would take the 25,760 gallons used on a full tank from the A-330, and place it into the 787 and see if would get there on the same fuel. Even though Boeing claims increased performance over the 767 as a 20% improvement, it would also becomes an over achiever against the A-330. Since it has the fuel capacity available to go even further for its destinations.
I will use a burn comparison between the 767 and the 787.
A fully loaded 767-300 travels a maximum of 4,260 nmi
(7,900 km). With a 20 % improvement for the 787 over the 767 performance, would mean the 767-300 full load of 16,700 gallons would push it only about 4,260 miles. Those same gallons in the 787-8 would take it almost to Frankfurt from Tokyo going 5,325 miles, just 550 miles short of the runway on the same fuel. This means ANA only has to load an additional 2,000 gallons on the 787, to bring it up to about 18,700 gallon load on the 787 for this route. The A-330 would need all of its 25,760 and then some to make the journey. The difference in cost is now a difference between (25,760 gals., for the A-330)- (19,000 gals, for the B-787) equaling 6760 gallons in fuel savings flying the Boeing aircraft. 6760 (gal) X $2.969 a gallon cost provides the airline with savings on one-way of about $20,000, and $40,000 round trip.
There you have it from the 787 20% fuels savings advantage Boeing has over its own 767 model. You apply the fuel capacities an distances for the A-330 to the capabilities of the 787 has over its 767, which is causing Airbus to look at those gallons lost to the Boeing 787, and wondering how to bridge this problem.