I have just got an S Type diesel, 2005. I saw that the previous owner was managing about 24mpg. I got that up to 29.5mpg with a weeks worth of leisurley country driving. But now, back in the city it is back down to 26mpg.

I was hoping for better than that. What do you get as an mpg?

 

A friend used to get 38mpg (UK gallons) from his.

 

Thanks for the reply. I saw on Top Gear an 'economy' run where Clarkson was in an XJ diesel and he got 35mpg, often booting it on the motorway. I'll give it a few weeks and then see if it gets better. I am sure it is not my driving. I could get 30mpg out of my Volvo S80 2.4 170bhp petrol in normal driving.

 

Had a near 200 mile country run, sometimes taking it easy and sometimes not and got an average of 39.1 mpg. I supose if I took it very easy, the 46 mpg suggested as the best figure for the diesel would be possible, just.