All kudos to no.naim for the FS17 version. I did just the conversation and wrote the change capacity script.

You can choose the capacity after purchase (default key K). 54000, 75000, 100.000Liter. Choose wisely, depending on the material you transport. Once you started to fill it, you can't change the capacity anymore. You've to unload it first.

Features:
- Capacity: Chooseable after purchase: 54.000, 75.000 or 100.000 liters
- Dosing rolls on/off
- Wheel choice
- Moveable drawbar