This depends entirely on how the H.S. Class is taught. All AP Classes are not of the same rigor. There is a huge variation of quality this depends on the teacher & how they teach the class.

And what you mean by substitute for college level classes varies. Depends on what college class you want to replace, and at what university. Typical AP course is only a one semester/one quarter not an entire year. Non calculus AP Physics doesn't really help you unless all you need is a Gen Ed Science credit. AP Calculus can replace anywhere from the first semester to the whole year, it depends on what your going to do with it. Are you a Engineering Major or studying pre-Med?