The main issue with using barrels to transport large quantities of fluids around is the tedious work of moving the empty barrels back to the filling area. Not to mention you hold less fluid in a cargo wagon of barrels when compared to a fluid wagon. You need to watch how many barrels are in the base so you don't deadlock full of empty barrels. But with this mod, it adds a Single-Use Barrel so you don't need to worry about recycling empty barrels!

You can also change how much fluid is stored in a barrel and how many it stacks to!