Scrub radius:
https://en.wikipedia.org/wiki/Scrub_...20be%20present.

I guess, as neilr knows, what a scrub radius is, without looking it up, he knows what he is talking about and you should listen to him and think twice about buying those XF wheels...
I am sure, the Ford-designers (The S-Type was designed while Jaguar belonged to Ford), would be pretty good at designing something like that. They might be pretty bad at designing a fuel efficient engine, but I am sure they would be good when it comes to suspension, esp. Jaguar. I know what I am talking about - I worked in Ford and Jaguar design teams. So, they would have thought about the offset and changing it would then probably not be a good idea.

I mentioned that bringing the wheels further out on my van was a massive improvement, but that van wasn't designed by Jaguar. Well, it was designed by Ford, but I wouldn't think they care too much about the design of a simple van...

PS: My van was like a Fred-Flintstone-car: Every change was an improvement!

 

This article is easy to understand too: https://www.carthrottle.com/post/wha...-it-important/

I have been there, bought wheels with wrong offsets and spoiled the way the car drove. No accidents or major problems but switching returned the car to its original "correctness". One can change if one wants to, but it is always good to know what the trade-offs are