Sometimes the most practical engine in the line-up – the diesel variant that real people actually buy with their own money – can be one of those cars that serve merely as a base of operations from which manufacturers spout the various sorts of sexy propaganda for the mightier versions. They’re about as exciting as porridge. It might do the job satisfactorily, but it’s rare that anyone sits down to a portion with massive relish.

And yet here is the Jaguar XJ 3.0D V6 that will see something like three-quarters of XJ business in the UK, and it’s actually quite brilliant. And fast. And exceptionally quiet. If ever there were a case for putting ‘Diesel’ in big fluorescent letters on the filler cap, this would be it.

This engine does service in the XF S diesel, and there’s no change in the surprisingly non-portly XJ, even given the fact that the XJ looks considerably bigger. The numbers give some indication as to what to expect, with 0-62mph in 6.4 seconds, and 155mph, but meted out with unusual frugality: this limo should return 40-ish mpg if you drive it reasonably.

Which for the reasons of hooliganism, I didn’t. The V6 thumps out 275bhp and a particularly satisfying 443lb ft of torque, which you can access pretty much all of the time. The six-speed auto is a mind-reading joy, and if you feel the need you can still access the full-suite of XJ go-faster stuff, including a ‘Track’ setting that sees the dials turn red, and adjusts various car-related parameters and paddle-operation of the gearbox that auto-blips on downchanges.

It’s a bit firm around town if we’re being brutal, but the precision the slight tautness produces down a back lane is worth it. The steering is accurate, the brakes assisted but honest. The XJ feels and sounds slightly hollow though; this is a car that’s been pared back to keep weight down and then had the lux bits reinstated. Still, even with the stereo set to whisper, you fail to notice after about five minutes.

There aren’t many bad bits. People will still worry about the rear end, the clock on the dash looks a bit cheap and the shift paddles could be more tactile, but with this interior and engine/gearbox combo you’re looking at a car that has all the best bits of the German limo competition but with a slice of British brilliance. It’s a confident car that carries Jag further into the realms of unquestioned competition for Merc and BMW. In fact, the XJ feels like the one to have over the Germans. Bring on the group test.

Tom Ford

On your drive for: £1615pcm

Performance: 0-62mph in 6.4secs, max speed 155mph, 41.2mpg

Tech: 2993cc, V6, RWD, 275bhp, 442lb ft, 1813kg, 189g/km CO2