# How do I get the most solid fuel out of my crude oil?

I got a limited amount of crude oil and want to turn it into the maximum amount of solid fuel. However, solid fuel can be made from heavy oil, light oil or petroleum gas.

• Should I switch my refineries to basic or advanced oil processing?
• Should I crack my heavy oil into light oil?
• Should I crack my light oil into petroleum?

Let's assume I have no other uses for any of these resources.

I omit water requirement as not important.

# Should you crack oil?

You can transform 2 heavy, 2 petroleum or 1 light to 1 solid fuel.
You can crack oil products: 4 heavy → 3 light → 2 petroleum.

Heavy oil gives you 0.5 solid fuel per heavy unit. Heavy cracked to light gives you 0.75×1 = 0.75 solid fuel per heavy unit.

Light oil gives you 1 solid fuel per light unit. light cracked to petroleum gives you 0.66×0.5 = 0.33 solid fuel per light unit.

Result: You should crack heavy into light, but avoid cracking light into petroleum.

# Basic or advanced oil processing?

Best values you can get per oil product unit: heavy → 0.75 solid fuel, light → 1 solid fuel, petroleum → 0.5 solid fuel

Basic oil processing gives 3 heavy, 3 light and 4 petroleum per 10 crude.
Advanced oil processing gives 1 heavy, 4.5 light and 5.5 petroleum per 10 crude.

Total solid fuel per 10 crude:

• Basic oil Processing: 3×0.75 + 3×1 + 4×0.5 = 7.25 solid fuel
• Advanced oil Processing: 1×0.75 + 4.5×1 + 5.5×0.5 = 8 solid fuel

Result: It is better to use Advanced Oil Processing to maximize solid fuel yields.

• There is one reason to turn petroleum gas into solid fuel: if you're not currently using petroleum gas for anything else, you need to use it somehow to avoid stopping oil refining. – Kevin Reid Nov 27 '16 at 15:37
• How is this affected by productivity modules? Perhaps I should do the calculations and update this post. – Michael Graff Jan 16 '18 at 22:37