Display MoreThere are a few options to refinine oil .
Iam pretty sure that a single refinery can do every step of the way (Cracking the oil and refining the components) but has horrible efficency.But correct me if Im wrong
You can get better if you use the oil cracking unit (a multi block) to crac kthe oil before refining it.
And the best way is the distillation tower which is obscene but requires a ton of stainless steel and other high tier materials.
The Buildcraft refinery? All that can do is oil to fuel (which GregTech treats as diesel), though with fewer steps than GregTech machines. If you mean the GregTech single-block distillery, I see 38 recipes for it, none of which output cracked fuel/oil. Cracking the fuel doesn't look like that great an option for feeding a single-block distillery, though possibly it's a decent option when using some distillation towers.