Factorio Oil Refinery Ratios: Optimal Blueprint Layouts Explained

Basic oil processing is the simplest oil refinery ratio in the game: one refinery turns 100 crude oil into 45 petroleum gas every 5 seconds. There is no heavy oil and no light oil, which makes the layout easy to pipe and easy to understand. For the first few hours of a run, that simplicity is valuable because petroleum is all you need for plastic and sulfur, which means it unlocks red circuits and blue science quickly.

Advanced oil processing is the long-term answer because it gives you all three fluids from the same crude input. One refinery takes 100 crude oil + 50 water and outputs 25 heavy oil + 45 light oil + 55 petroleum gas every 5 seconds. The immediate petroleum gain is only modest, but the real win is flexibility: heavy oil can become lubricant, light oil can become solid fuel or rocket fuel, and any excess can be cracked downstream into the gas you still need for plastic and sulfur.

The practical rule is simple. Use basic oil processing only as a bootstrap, then rebuild into advanced oil processing as soon as you can support water piping and cracking. A blueprint built around advanced processing scales better because you can repurpose excess fluid instead of boxing yourself into a petroleum-only design that must be torn out later.

Advanced oil processing only works when you keep fluid backups from stalling your refineries. Heavy oil cracking converts 40 heavy oil + 30 water into 30 light oil every 2 seconds. Since one refinery only produces 25 heavy oil every 5 seconds, you need just a quarter of one chemical plant to consume that heavy output if you are cracking all of it. That is why refinery blocks often share a small row of heavy crackers across many refineries instead of pairing them one-for-one.

Light oil cracking is the bigger number. A chemical plant converts 30 light oil + 30 water into 20 petroleum gas every 2 seconds. If one refinery cracks all of its heavy oil first, the total light stream becomes the refinery’s direct light output plus the converted heavy oil, which works out to roughly 1 refinery : 0.25 heavy crackers : 0.85 light crackers. At larger scale, a clean fully-cracked block is approximately 20 refineries : 5 heavy crackers : 17 light crackers.

That full cracking ratio is useful as an upper bound, not a mandatory target. In a real base you usually hold some heavy oil for lubricant and some light oil for solid fuel or rocket fuel. The better approach is to blueprint enough cracking to clear overflow, then control those crackers with tanks or circuit conditions so the refinery block only cracks the fluids you are not currently consuming elsewhere.

Downstream demand determines whether your oil refinery ratio actually works. A refinery block that is technically balanced on paper can still starve if plastic, sulfur, and lubricant are drawing from the same tanks without clear priority. The safest method is to think in consumers per second, then size your cracking around the excess after those consumers are fed.

Plastic is usually the dominant petroleum sink because red circuits scale aggressively and modules amplify that demand later. Sulfur looks smaller at first, but batteries, processing units, and science expansion will keep it relevant through the rest of the factory. Lubricant is different: it only uses heavy oil, so it should be treated as a protected reserve before heavy cracking turns everything into light oil.

A stable oil blueprint is less about one perfect static ratio and more about priority. Put storage tanks on heavy oil, light oil, and petroleum gas. Feed lubricant directly from heavy oil first, then allow heavy cracking only when the heavy tank rises above your chosen reserve. Do the same for light oil: keep enough buffered for solid fuel or rocket fuel, and only crack the overflow into petroleum gas when that buffer is full.

In practice, that means your refineries run continuously, your lubricant line never gets stranded, and petroleum expands automatically when plastic or sulfur demand spikes. If your base is small, pumps on circuit conditions are enough. If your base is larger, split the block into repeatable modules: a refinery header, a heavy-cracking row, a light-cracking row, and dedicated product bays for plastic, sulfur, and lubricant. That modular approach makes expansion much easier because each new block copies the same fluid priorities.

The simplest checklist is: reserve heavy for lubricant, reserve light for fuel, crack only surplus, and size petroleum consumers to the cracked output rather than the raw refinery output alone. Once you do that, your Factorio advanced oil processing blueprint stops behaving like a hand-tuned puzzle and starts acting like any other scalable production block.