Save and re-zip the file with the same folder structure and place it in your ETS2 mod folder.
: Extreme versions found on the Steam Workshop can increase capacity to 5,000 liters or even up to 50,000 liters to eliminate the need for frequent refueling.
If you prefer not to use a pre-made mod, you can manually adjust the fuel capacity by editing the game's definition files: Use the scs_extractor.exe tool to open the def.scs file.
In the base game, fuel capacity is tied to the truck's chassis and brand. For example, the typically offers around 1,140 liters , while many Volvo models are limited to 800–940 liters . Mods for version 1.44 significantly expand these limits:
Truck's fuel tank capacities are, actually, too unreal? - SCS Software
: Some versions increase the capacity to 2,000 liters for all standard SCS trucks.