User blog comment:B214/Question and Answers 6/@comment-185.112.105.215-20180923044832/@comment-108.7.146.103-20181002230209

In what sense do you mean maximum power? In terms of destructive capability? Relative to one another?

See http://highschooldxd.wikia.com/wiki/Issei_Hyoudou#Equipment for details.