I found this 2007 thread on the old Roadfly forum when I was searching for something completely different (cue Monty Python background music):
Antifreeze coolant in-depth synopsis

 

Thanks Michaelh!, its sure is confusion deluxe trying to get these old specs. I did get a reply with recommendations from Febi(excellent customer support!), "Febi coolant 171998 based on the Ford release ESD-M97B49-A" so that's what they recommend, blue color apparently. I did at first bye the later wss spec(before I read up on what's what with Jag coolant), don't know what's in the system now but will flush several times before adding new, might have been replaced with never spec.

So changing to later wss would work? read some scary stuff in some other thread....

Cheers!

 

Indeed it is.

My car came with DOW (at least I'm pretty sure it was green). When I started servicing it myself that had changed to yellow - or was it orange? - so I assume that the dealership changed it at some point, probably when it had a reman. motor fitted in 2004.

I was aware of the confusion (i.e. I was confused) over the colour as identification so I did a full flush at my first change.There's a good article on flushing the system by Mr. Texas Dan here:
http://matt.zenfolio.com/xk-coolant-...tat---v1-1.pdf

although his choice of G-05 coolant is possibly wrong, depending on which side of the argument you take.

I now run Jaguar WSS-spec OAT coolant . Possibly that's wrong, but was the 2004 reman built with updated parts so it's not an issue?

All I can say is that I've had no issues in the last 12 years or so since I first filled with OAT, although my car doesn't see a lot of miles.