Can anyone here with a XJ81 with the 6.0L V12 tell me what oil you are using?
I have done some research using google to look at various threads and there does not seem to be good consensus on this issue.

 

That's sorta like expecting a good consensus on the best beer

My V12 gets 20/50 expect in dead winter when I switch to 10/40. Non-synthetic, whatever is on sale that day. I usually throw in some ZDDP additive. What the hell, right?

The 20/50 is a bit of a favorite for some but there are logical arguments against it.

I use Baldwin filters, by the way, even though you didn't ask

Cheers
DD

 

That's what the workshop manual says:




I am personally using 10W/40 (HC-synthetic) but I don't operate it in winter.