New apps mod for Assetto Corsa adds an app named "Fuel Manager". This app automatically calculates and sets the fuel needed for a race based on your driving and best lap time. It features a fuel calculator in the setup menu and real-time fuel usage sampling. You can easily turn the app off with a single button press.
All credits to: Damgam
This mod requires the Custom Shaders Patch to be installed in order to function properly.