If i have a Saab340B that has a configuration of 30 standard economy seat instead of the factory default of 34 high density seats then will it use less fuel? In real life yes but is it something that is taken into consideration on AirwaySim?
Its range will increase but the fuel consumpsion will be the same
Seat config does not affect the OEW of the plane (left out to keep it simple), but when making the actual route calculations the number of seats sold (payload) does affect the _actual_ fuel usage of each individual flight, so a bit of the same thing.