Hmm, that sure is a tricky one. For a start, is there SI analog for “bhp”, or should CM just use “*”?
The tricky bit is those inputs in Content section: those are for editing, and the idea is to keep all the mods’ data in the same style, so modders, releasing their content, would still use the same units Kunos use. I can add some sort of two-way conversion in there, but some users might put some extra data or even unreadable values in there, and that data will be lost.
By the way, you can see power-to-weight in Content section if you have this option enabled:
Then, since it’s not a real input anymore, CM can (relatively) safely convert a value before displaying it.