I am fully aware that most vehicle repair manuals have some sort of copyright protection but my confusion is regarding what specifically is protected and more specifically, things like fluid capacity values and bolt tightening specs.
If this information is copyright protected (the actual specifications / values listed) how is it that multiple manuals from completely different companies all list this information in a nearly identical way? Sometimes there are differences, but mostly not.
Looking in the front of various manuals, it seems that the copyright protection is on the manual producer themselves, pictures, methods etc. For example, Haynes / Chilton does not reference Ford copyrights or that they have permission from Ford in a Ford Escort manual. Is information like this considered common property ie. no ability to copyright?
Reason for asking: Has to do with online repair blogs and how to stay legal.