I thought maybe higher level units require a higher maintenance cost, but the civilopedia says support is 1 gold per turn per unit, but different government's give free units based on the number of towns, cities, and metros you have.

You don't maybe have captured units do you? Like artillery? Capture units are free, but I'm wondering if you upgrade them they switch from captured to normal? I don't think that's correct either.

In the editor, under units, there is simply a 'Req. Support' checkbox. So not a variable amount.

Under the Governments tab, there is a Cost/Unit setting and Free Units Per Town/City/Metro settings. So the 1 gold per unit according to the civilopedia is not completely accurate.

The only other thing I can think of is corruption being recalculated/shifting after the upgrade causing the gold per turn to be altered.

If you have the Smith's Trading company, I suppose income can drop due to overall treasury going down

Oh that's true. You need to keep 1000 gold in the treasury at all times get the max bonus (which is 50g per turn). So if your upgrades cause you to drop to say 950g in the treasury, your gold per turn would drop by 2.5g (not sure what direction it would be rounded), but that could certainly account for a 1 to 3 gold per turn difference.

Err. Just remembered, not Smith's Trading Company...that pays for the maintenance on 'Trade Installations' (such as marketplaces). Wall Street is the one that gives you gold per turn based on your treasury.

Originally posted by B.O.B.:

Err. Just remembered, not Smith's Trading Company...that pays for the maintenance on 'Trade Installations' (such as marketplaces). Wall Street is the one that gives you gold per turn based on your treasury.

Oh, yeah. My memory kills me off sometimes T__T

Ah, good call, guys. And it does happen later in the game, which would make sense given the timing of Wall Street's availability. I will see if that is it or not. I'm sure it is.

Thanks for the input.