Hi Jon
I was thinking about buying a diesel the other week and did a bit of looking into this Ad Blue, since I’d never used it before.
As far as I can make out, Ad Blue is ONLY injected into your exhaust pipe (NOT your engine) and it is only used to convert the harmful nitrogen oxides in your exhaust gasses into cleaner, more breathable air (very similar to a catalytic converter in a petrol car).
As the Ad Blue is only there for one specific, narrow purpose and doesn’t go anywhere near your engine, I would think that any additives you put in your fuel tank or engine oil should be fine and not conflict with it in any way 😊
I hope that’s helpful, but please do your own research on the internet or ask your Jag specialist, coz there’s lots of useful info out there.
(Just so you know, I didn’t buy the diesel in the end, so haven’t tried it myself!)
Happy motoring!
Si