Factorio Forums

I've read recently that the 4:7:1 ratio of refineries:light cracking:heavy cracking is not optimal. Can anyone elaborate or point me towards forum resources to reference? Thanks!

People told you wrong.
With advanced oil processing :
4 refineries produce 4 Heavy, 18 light, 22 gas
1 heavy cracking turns 4 heavy into 3 light (total 21)
7 light cracking turn 21 light into 14 gas (total 36)

With basic oil processing (only other alternative) :
4 refineries produce 12 Heavy, 12 light, 16 gas
3 heavy cracking turns 12 heavy into 9 light (total 21)
7 light cracking turn 21 light into 14 gas (total 30)

so best ratio with vanilla and no modules is 4:1:7

With the max 40% Productivity upgrades on cracking (you would need beacons) the 2xbasic oil processing gives a more respectable 38.96 gas but is still beaten by 4xadvanced oil processing giving 42.72 gas.

Tnarg wrote:With the max 40% Productivity upgrades on cracking (you would need beacons) the 2xbasic oil processing gives a more respectable 38.96 gas but is still beaten by 4xadvanced oil processing giving 42.72 gas.

Beacons can't hold productivity modules. The maximum is 20% productivity.

Koub wrote:People told you wrong.
With advanced oil processing :
4 refineries produce 4 Heavy, 18 light, 22 gas
1 heavy cracking turns 4 heavy into 3 light (total 21)
7 light cracking turn 21 light into 14 gas (total 36)

so best ratio with vanilla and no modules is 4:1:7

You're completely ignoring that the different "recipes" take different amount of time to process.

4 refineries produce 4 Heavy, 18 light, 22 gas every 5 seconds
This can only support 0.8 Heavy cracking facilities.
The combined light oil from the heavy cracking and refineries can only support 5.6 light oil cracking facilities.
Only thing about it is that 36 petroleum gas would be produced (every 5 seconds).

The correct ratio is 5:1:7.

I agree with 5:1:7 without any modules and advanced oil processing.
I think the main oversight was, that the refinery has a production speed of 1, while the chemical plants have a production speed of 1.25.

So if I only could support 2 refineries what does that work out to?