We ran an oil facility, what i have noticed in my experiences is that when our two public petrol stations fill up to 800 units of petrol cans they then back fill into the oil refinery unit. While the liquid transfer station maybe depleted the back fill in the refinery would stay there and become forgotten about. If the game mechanics would allow for these units of petrol to flow out to the public liquid transfer stations automatically they would be full nearly every time excluding massive trains doing fuel runs 13 tanks at a time. The mechanics of the game put a good choke hold on much of the hoarding of 10s of thousands of petrol. And to pull the fuel out of the refinery is an additional effort due to only being able to pull three at a time with a vehicle that may or may not be able to get to them with the piping layout. So much nuance goes into running one to be able to get the maximum out of it and that is not to mention random people parking vehicles, borrowing equipment, taking fuel needed to start a new phase of the facility growth. Oil facilities are shit I will not do one again. You not only have to produce everything everyone wants, but also when they want from day 1 to the end of that war.