So as a New player to the game I have no idea what this "classic" means so could you list the ratios and add pictures?

Currently in game if you doing basic
you put in
100 Crude

you get out
45 Petro

Currently in game if your doing advanced oil
You put in
50 water
100 Crude

you get out
25 heavy
45 Light
55 Petro

if this mod changes this could you at the very least List what it gets changed to?

Hi, please look at the change log. Specifically the first couple of entries should have everything.

There was a lot that got changed by the devs as a direct result of the recipe changes.

There was one big change, and a few smaller changes. The one big change was that basic oil processing used to give you all three outputs instead of just petroleum gas. The three outputs it gave were more heavily weighted towards heavy oil. The smaller, unrelated change was to make producing rocket fuel require a little bit of light oil in addition to solid fuel. And then there were a bunch of adjustments to the tech tree to account for the fact that you couldn't get anything but petroleum gas until you had chemical (aka blue) science.

But, the big change is the most obvious one. A lot of people wanted their old factories to continue to working, and also disliked the 'dumbing down' of oil processing. It was a controversial change, which is why FuryoftheStars made this mod. :-)

I'm not sure how that could be adequately represented in an icon.

Ok, I went ahead and took the time to make up some comparison images of the recipes. The techs are too hard to capture like this. You're going to have to review the change log for the rest.

Thank you. Useful mod.