I need it for specific project, where this is set as code standard.
But, whatever I put, it always displays with tab size of 4. If I even put it into Base File.sublime-settings - User, as deault for all file types, it also will not display 8 for C files. It works for other file types. Not for C.
SublimeText2 dev version 2135 (latest at this date)
A couple things to check: Do you have detect_indentation set to true? If so, it may be automatically setting the size to 4 because it looks like a file has 4-space indents. Do you have the indent width set separately in Packages/C++/C++.sublime-settings? If so, this will override even your user settings.