im pretty sure the meta is just as "tall (units upwards in drill builder)" as possible with storage behind that. im having a lot of feul problemss but its a great game
I add 2 tanks per 1 drill and it seems to give me plenty of fuel.
Unless I add tools like the coal grabber thing. I'm still finding out how much fuel to add to balance those properly for me.
with 2 or 3 battery packs, 2 coal grabbers and the worst drill, i've managed to get infinite fuel and be able to go until i break.