That's why any executive car maker worth their salt has got to have a decent diesel at its disposal, because while the slippery stuff costs a little bit more you get an awful lot more for your gallon. Look through the sales figures of any swish saloon and it's no longer the silky straight sixes and the thumping V8s that are the big sellers. It's the ones you fill up with the black pump.
Jaguar's been lucky to have a superb diesel - the 2.7 litre, Citroen-derived V6 - to call on in recent years but it's this smaller, 2.2 litre unit that really matters for the XF. Finally, more than four years after the saloon's introduction, it's got an engine that can actually hit the 5-Series, the A6 and the E-Classs where it hurts. The 2.2 XF diesel could and should be the firm's biggest seller.
The improvements aren't just limited to the engine room, either; you might have noticed the XF got a facelift last year, meaning the slightly-clumsy headlights are gone in place of some much sharper, XJ-style ones. I can think of few cars whose looks actually improve after the now compulsory midlife makeover, but the XF's one of them.
Anyone venturing inside won't find the church pew dashboards and acres of cream leather you got in this car's ancestors but what you get instead is Jaguarness with added modernity. The way the rotating gear selector for the slick eight-speed auto rises out of the centre console, for instance, is very Gadget Show, but the use of wood, leather and tech make the cabin infinitely more interesting than the wall-to-wall black leather you'll get in BMW's 5-Series.
So would you buy one over the Beemer? Both cost £30,000, both will prove cosseting and comfy companions and both come with all the toys any thrusting middle-management type demands, but it depends on what you're looking for. The BMW, by a whisker, is the more refined of the two and will go ever so slightly further on a gallon, but the Jag's better looking, more characterful and more fun when it strays off its natural habitat of the motorway's outside lane.
I'd take the Jag.