The two newest servers, Andromeda and Bravo, have an additional feature designed to prevent massive fleet buildup. By adding an ongoing fleet expense the newest servers seek to limit the amount of fleet a player can possibly support. This is supposed to make the game more competitive, and possibly prevent the problem of previous servers being controlled by a handful of very high level players with huge fleets.
Fleets have a maintenance cost that is deducted from the empire hourly income. There is a limit of fleet that doesn't pay maintenance and above that limit there is a maintenance cost for any additional fleet.
Free supported fleet = Economy^1.6+(Economy/100)^3.2
Fleet Maintenance = (Fleet above limit/125)^0.7
Actual Limits and CostsEdit
Although it is not clear exactly how these figures are rounded the fleet limits look like this:
Economy= 10 --- Fleet limit= 39
Economy= 100 --- Fleet limit= 1,585
Economy= 250 --- Fleet limit= 6,884
Economy= 500 --- Fleet limit= 20,986
Economy= 1000 --- Fleet limit= 64,680
If your economy were 5000, the fleet limit would be about 1.1 million. If you were to double that amount to 2.2 million it would cost you about 12% of your income for maintenance.
If a player with economy of 5000 had a fleet of 5.5 million, it would reduce his income by about 30%.
In fact, the eco 5000 player could support up to about 25 million in fleet before he overpowered his economy.