Reason why I'm writing this suggestion is pretty basic "Fluid handling" solutions.
To the point - if I count well, we have 7 types of liquids in game:
- water,
- oil,
- heavy oli,
- light oil,
- petroleum gas,
- libricant,
- sulfuric acid.
After we discover Fluid handling, we have opportunity to fill empty barrels - BUT, only with crude oil.
Since ver 0.13.0 we can build Flamethrower Turret which demand rafined or crude oil in order to work. Crude oil can be barreled and picked up by logistic robots who may deliever it to request chests all over close to deffence lines and then can be pump by assembly machines into the storage tank (or direct) which may supply nearest area (far far away from our refining plants).
Same goes to Sulfuric acid. Proccessing Unit and Battery assemblers in most of the times are far away from Sulfuric acid tanks since they needs several other items in order to craft.
1) My suggestion is to add possibility to fill barrel with ALL 7 types of liquids in order to move them as an items. Same as Storage Tank, full barrels shall receive color of liquid it contain. Empty barrels shall be called "Empty barrel" not "Empty crude oil barrel" as it have place now.
2) Another suggestion regarding this subject is possibility to reduce Storage tank capacity as it have place with all types of chests. Storage tank at the moment have 2500 units, and we have no option to decrase this number.
3) Cistern wagon - it's sad that we have only 1 type of cargo wagon in game, since we have numerous liquids to handle.
4) Minor idea is to add Pump energy consumption (fuel or electricity) - at the moment it's perpetuum mobile which is irrational

That's it for now. I would like to other players oppinions. Maybe someone discover any MOD which is close enough to my ideas.
Regards,
Res0r