Hi/Lo series XF's
Reading the workshop manuals so I could sort the XF limo out, I came across a lot of references to "hi series" and "lo series". However, that's all they wrote, and I've never seen it anywhere else.
So, exactly what are Ford talking about? What _is_ a "hi series" or "lo series" XF?
BTW, I did do a search on these forums, but the search engine doesn't like the words "hi" or "lo", and all I got was a lot of threads with "series".