system
Given the following post, respond as if you're commenting on Reddit:
human
[DC] How much does Superman "hold back" as Clark Kent?

He can carry cars with ease, fly, and do almost anything your world- class weightlifters can do hundreds and thousands of time more. 

So I'm guessing when he's faking it as Clark Kent, he has to be holding back a lot? I'd assume he has to treat everything as being very fragile? How does it work? Does he still operate like a "normal" human when not displaying his powers? Or is he forcing himself to not output all his strength?

Basically, does he need any effort in restraining himself from using his full power when he's playing his Clark Kent persona?
gpt
Without actually quantifying his strength, we can't quantify how much he holds back.

The last time a Superman was given a strength test, he was holding up the equivalent of the weight of the Earth for five days straight before he started to sweat. But that was the Post-Flashpoint Superman, who wasn't the same character as the Post-Crisis Superman (or the merged character that exists now).

We also don't know when/how his strength kicks in - is it always on, thus he has to limit himself to a fraction of a percent of his actual strength, or does he have to consciously use his strength, gauging it depending on the response of his foes? Most material seems to point to the former.