Allow Foreign aid to FA oil.
The price of oil is the most highly variable out of all the market transactions. Being able to FA oil would decrease how much it would vary normally.

Counter argument is, in an attack, you gain cash, you gain food, and kill military, only oil is not affected.

So if oil should be able to be FA'ed, then it should be able to be taken while grabbing someone. (I do not care about this point, but would also stop people from stocking oil for this sole reason)

In say 1a, a facist oiler cannot support his clanmates as directly as say a casher, because he can not give his oil away.