I find it implausible that the A340-300, with 4 gas guzzling engines made in the 1990s, only runs at 39,936 fuel flow. Not sure if the numbers can be hot-fixed at all, but for the sake of realism & accuracy they really should be. It's the one of the most efficient long-haul aircraft in the game.
I also don't think this is an isolated problem. The C919 has a ridiculously low fuel flow of 11,827 and holds 190 passengers. Only downfall is the 1898 mi range. But this is almost unbelievably efficient when the A320NEO (189 passengers) sits at 14,994 and B737-8 max (200 passengers) is at 15,401. I think I smell fish here...