Low Grade Fuel

It's Animal Fat and Cloth, that's it — no research, no workbench, craftable from the moment you spawn. Three fat and one cloth makes four fuel, so it scales cleanly no matter how big a batch you queue.

Where the ingredients come from

Animal Fat drops from skinning almost anything you kill — deer, boar, wolves, bears, horses, even chickens give a little. You don't need to hunt specifically for it; if you're killing animals for meat and cloth anyway, fat piles up as a byproduct. Cloth comes from the same animals, plus hemp plants if you're near farmland.

The actual grind

Early wipe, fuel is really a hunting problem, not a crafting one — go kill wildlife along the coast or in the green zones near your base and you'll have more fat than cloth most of the time. Skinning knife speeds this up noticeably over a rock or hatchet.

What it's actually for

Low Grade Fuel runs furnaces, lanterns, the tool cupboard's decay protection, and every vehicle in the game. It's also a hidden ingredient in a lot of higher-tier recipes — sleeping bags don't need it, but Explosives, Furnaces and several weapon rounds do. Keeping a passive stockpile going is worth more than a big one-time craft.