Change motorboat fuel type and consumption rate

[Luizza]

Messing around in the devkit, just trying to learn all the things and have fallen down at my first learning project. I want to change the fuel a modded version of the motorboat consumes, making an 'ecoboat'. Where on earth do I find that value, I read every single entry and I still have no clue, it doesn't appear to be in the  dino 'food' section, or am I missing it?

Any expert out there can point me in the right direction? No need to tell me exactly what to do, just where do I start? Give me a clue