Series 1 XJ6 Cruising Speed

What is the comfortable highway cruising speed for the S1 with original BW12 and rear end?
I believe it’s 3.31 …

TIA

Hi Demian, our car is exactly that specification and runs well and quietly at 110 - 120kph. Overtaking is a top gear exercise and I am usually up to 140kph when I ease back into the lane. Highway running yields 21mpg (imperial) on a regular basis. Paul

Genuinely appreciate that Paul.
Thank you…
Still tinkering and looking to use her as an everyday car, Or considering purchasing a later model S type.

But it just would not have my affections as this one. I would like it, but it is not my dream car.

I’m eccentric, Jaguar nut as all of the rest here, always managed before with an old Jaguar, so I believe I can manage for the most part. I haven’t a big commute.
I just enjoy them too much.

May just get a cheap economy car for the grind of course.

Anyway, thanks again.