Details on Superscoring

I have a question. When colleges superscore, do they look at the composite only?
Another question: does the subscores factor in? On english, i got a 18 on usage mechanics but a 15 on rhetorical. Since i can choose which questions to do, and if i get a 18 in rhetorical, do i have a 36? Or does it omit the subscore and calculate the xx/36? Sorry if the question is confusing. I got near perfect in one of the two superscores for englsih and reading and im hoping to utilize my time wisely to get a higher score.

Here is how is works for super scoring.

Say your first ACT was ( I’m just making up numbers)…

34 E
31 R
32 S
29 M

Second ACT was
33 E
34 R
31 S
31 M

The super score would be the highest score from each section

34 E
34 R
32 S
31 M

Section subscores will not be used in the super score.

thanks, and @HereToHelpYou , thanks for the free act tips!!! I felt really confident today. Especially on english and reading, science was a little difficult since i didnt practice it since my last test.

Good for you @ikim16, I was happy to help you. Thanks for letting me know.