I'm having a hard time understanding the exact fuel burn issue that you're describing. Can you point to the fuel burn reference documents that you're talking about so I can see for myself?
The other thing to keep in mind is that the plane acquisition costs in game are dynamic based upon the demand of the type, so that will vary from game to game depending on what sells well.
The A346 is mostly comparable to the 77E's real life fuel burn, but it's really the maintenance costs on the engines that have caused it's early demise.
The other thing is that the stated fuel numbers for planes are blended averages of the behind the scenes game data, which applies takeoff, climb and cruise capabilities and related fuel burn. So, for example, two different planes with the "same" fuel burn in a game could end up with vastly different real fuel burn when they are used on the same route.
I'm sorry but I don't think anything you said is accurate.
The fuel burn rate between a 777-200 and an A340-500 isn't comparable. If it were, the A340 would still be around.
There are many sources of data available on the net. Even with that, all commercial jet turbines are optimized for cruise performance in RVSM airspace. If your cruise numbers are worse than a competitor's, you are not going to survive long in the market place regardless of your burn in taxi/take-off/climb/descent/landing.
However, I will reference a pprune source, as this information seems to concur with most publicly available data.http://www.pprune.org/archive/index.php/t-220792.html
"Hard figures for the A340-500HGW and 777-200LR are as follows (the figures for the A346 and 773 are comparable):
engines: Rolls-Royce Trent 556
engine's specific fuel consumption: 0.568 lb. of fuel per lb. thrust per hour
engine's maximum thrust: 56,250
engine's cruise thrust: 11,000 lb.
typical seats: 313
engines: General Electric GE90-110B1L
engine's specific fuel consumption: 0.530 lb. of fuel per lb. thrust per hour
engine's maximum thrust: 110,000 lb.
engine's cruise thrust: 19,000 lb.
typical seats: 301
As you can see, the GE90 has about 7% lower SFC (0.530 v 0.568) compared to the Trent 500. This would give the 777 a small advantage alone (the A340 has only 4% more seats than the 777), but the A340's problems are compounded by its higher total thrust requirements, due to its higher weight. Why is it heavier? Primarily because both the wing and the fuselage were pressed into service outside the limits of their original design. The fuselage for example is narrower than that of the 777, so it has to be longer; this increases weight in the same way that bicycle frames with narrow tubes are heavier than those with "fat" tubes (i.e. the walls have to be disproportionally thicker in the narrow tube for equal strength), and also because the longer fuselage must be reinforced to counter bending moments.
The wing's cross section and sweep were likewise optimised for a lighter plane travelling at slower speeds. So the A340 has higher SFC, lower speed (therefore more time in the cruise burning fuel), higher weight resulting in a higher total thrust requirement, and only slightly more seats to counteract these disadvantages. It is no mystery why Boeing sold ten times more 777s than Airbus did A340s last year. The only question that remains is whether Airbus made the right decision in massively reducing development and manufacturing costs by using an existing fuselage cross section. With hindsight it increasingly looks like that was a mistake (because of sharply rising oil prices), and that A340 sales will slow to an inevitable halt in the near future."
For the record, my numbers of SFC for an A340-500 on a per hour basis is 24992 lbs.
Consequently, the numbers I have on a 777-200LR are 20140 lbs per hour at cruise.
The SFC fuel burn ratio of an A340-500HGW/777-200LR at cruise would be ~ 1.241.
Secondly, the A340 has a slower cruise speed (0.82 vs 0.84 approx). This means it will burn more fuel longer than a 777-200LR on the same flight. As an example, for a 10 Hour cruise segment, the A340 would spend a little over 2 percent longer in cruise, each way. On a single leg, this translates to slightly more than 12 minutes longer in cruise, which is an additional 5000 lbs of fuel. Even if one has a lower aircraft gross weight at the end of cruise, and the SFC is something more like 0.5 rather than the average 0.568, this is still wasted fuel compared to the 777-200LR with it's higher average cruise speed.
The maintenance costs were also prohibitive. This is due to Rolls using a three spool engine design rather than a two spool engine design. http://www.pprune.org/tech-log/444991-american-twins-brit-triple-spool-engines-2.html
Even when Airbus and Rolls offered a deal to all carriers to help defray the costs of maintenance on RR engines and used upgrade incentives to increase fuel efficiency competitiveness like they did on Iberia's 757 fleet, it was not enough to save the A340 production line from being shut down as the 777 economics in operational efficiency and maintenance were superior on most levels. GE engines do tend to have a shorter overhaul interval, but if the engines are leased and the refit is planned, a switch-out and RTS isn't especially problematic, except the additional leasing of engine spares which all airlines do anyway.
Anyway, as I was saying in my primary point, the operational data is not reflected in the game as I originally asserted and simply means the economics of the "airline management" aspect are not being modeled to preserve the key aspects of aircraft operations and relative efficiencies which drives new aircraft development and determines just which one is better in the market place. This means during highly volatile economic disruptions like exorbitant fuel prices, there is no penalty for clinging to an inefficient platform and there is no reward for choosing a more efficient platform. This simply means the abstraction of the game from aircraft factual data is so extreme, it makes it less a game based on real world data, but instead based on whoever determined the abstracted values. If one looks at the average fuel burn values assigned to each type in this game, they will see that they are wildly inaccurate even when converted to metric.
Also as I stated before, there are other certain aircraft performance factors that are grossly inaccurate like Cseries CS100: Required runway at MTOW, range with full passenger load. It makes me wonder why even reference actual aircraft. The 777 was specifically designed to replace four engine commercial aircraft using ETOPS but it is made uncompetitive on a straight cost basis, on an operational basis, and I can't see the refit basis being all the impactful unless the difference is greater than 50%. So why use real world aircraft designations at all? I could just go play Airport Tycoon instead.