By now you’ve probably read our reviews of the various new versions of Jaguar’s 2010 XJ.

If one thread runs through all of them, it’s the one marvelling at the unlikeliness of this car’s transformation from old-fashioned, old-English luxury conveyance to modern thoroughbred sports saloon.

To understand the completeness of this metamorphosis, you need to get stuck into a few of the gorey details pertaining to this great big Brit four-door.

For starters, the XJ’s got the same steering rack as an XFR; only its longer wheelbase and slightly softer chassis makes it any less agile than the smaller M5-basher.

Next, there’s a mass issue to consider: because an aluminium XJ Supersports actually weighs less than the largely steel, identically engined XFR. If it’s any slower, therefore – and it isn’t much slower – it’s because of the way the larger car’s drivetrain and running gear are configured.

Then there’s the more sophisticated ‘Dynamic’ chassis mode that the XJ has relative to the XF. When you press the button marked with the chequered flag in the XJ, you get slightly meatier steering feel as well as higher-rate damping and sharper pedal response.

Stick the transmission in ‘S’ mode and you also get a more sporting software setting for the automatic gearbox. Tug on a paddle to enter manual mode and you’ll find that even the diesel version of this car will hold a gear right up to the engine’s redline, giving you total manual control of the car’s gearshifts.

Also, that gearbox is clever enough to delay a downshift, rather than aborting it without letting the driver know. Say you’re braking hard into a corner, and click twice on the left-hand paddle in quick succession to go from 4th to 2nd.

In most flappy paddle ‘boxes you’ll only get 3rd, because the software involved makes a decision that you’re going too fast for 2nd at the moment the command is made. The XJ’s ‘box, however, recognises that you’re slowing down, and delivers the change into 2nd at the point at which it becomes possible without over-revving the engine. Jaguar calls that ‘bending the shift line.’

That’s just one of the ways that they make this 5.2-metre executive saloon feel like a proper driver’s car: it’s one of the many lengths they’ve gone to in the process of giving the XJ the same dynamic DNA that you’ll find in an XK or XF.

If you ask me, they have emphatically succeeded in creating a large executive saloon that transcends the normal restrictions and definitions of its class. This is a Porsche Panamera Turbo and Aston Martin Rapide rival; it makes a Mercedes S-class look boring and obsolete.

Technorati Tags: , ,