[KrisKrinkle]

Can those percentages be altered? Using different processing, can they make less gasoline and more of the other stuff from the same barrel?

[nascarnation]

I believe the answer is yes, within some limits.
I’m sure experts on here will give a more precise answer.

[ConservativeInPA]

They don't refine every barrel of oil that way. This is just a representative model of what could be refined from a barrel of oil. Not all oil is equal. There are different grades of oil that found in different oil production areas. For instance, in Pennsylvania oil has been historically used for lubrication, i.e., Quaker State Motor Oil, and for the production of kerosene. So, some oil is more suitable for one type refined product and others not so.

Natural gas isn't consistent in quality either. The futures basket quantity for natural gas is in thermal units because not all sources of natural gas have the same potential energy per cubic meter. Different locations also have different levels impurities, hence you will sometimes hear talk about dirty natural gas (not some environmental whacko talking about clean energy.)