Jaguar XJ is pussycat and predator on track and road

Such films would have us believe that anyone who travels in with copious amounts of legroom and a trained chauffeur stationed at the wheel will have to escape terrorists or a criminal cell at some point.

Of course, that’s not the case, but there is an ever-growing requirement for large executive saloons to handle the rigours of high-speed driving.

That’s why Jaguar headed to the infamous Nurburgring to hone its new XJ and why it was confident about letting group of journalists put the cavernous long wheelbase version through its paces on road and track at Silverstone.

First, we head to the XJ's more natural habitat.

Lined up in the Silverstone in-field the row of XJ’s strike an unusual contrast with their surroundings.

Race prepared Ferraris and Porsches lurk menacingly in the background and bikers display scary levels of bottle by tearing down Hanger Straight flat-out just yards away.

Sharp, sleek and unmistakably a Jaguar, the XJ is an distinctly modern take on the executive saloon and I’m quickly isolated from the manic pace of life outside as I settle into its leather clad armchairs.

Shutting out the noise and drama I’m presented with an interior with an almost aeronautic air.

It’s a luxurious space bathed in light from a full-length glass roof and adorned with a level of design detail more usually found in a Bentley.

Turbine-style chrome air vents bulge from the leather fascia, while Jaguar’s rotary gear selector rises majestically from the centre console with a prod of the starter button.

XJ prices start at £53,900 and there is a £3,000 premium for the additional 125mm of rear leg room offered up by the long wheelbase version.

That’s around £6,000 less than the BMW 740Li (£62,190) and Mercedes’ (£61,940) long wheelbase S-Class 350 CDI.

Driven here is the Portfolio long wheelbase equipped with Jaguar’s three-litre, V6, twin-turbocharged V6 diesel engine.

It sits below range-topping Supersports spec which is exclusive to five-litre V8 cars in 385bhp or 510bhp supercharged form.

Among this test car’s spec is radar-equipped adaptive cruise control and a stunning 1,200 watt Bower&Wilkins stereo which spent a short time as the most powerful stereo in a production car.

Leaving the confines of Silverstone’s access roads and heading into the surrounding countryside the XJ immediately reveals feels composed, refined and usefully rapid.

Shared with the XF Diesel S, its diesel engine produces 275bhp and a stonking 442lb.ft. of torque, enough to propel the XJ to 60mph in six seconds, while producing 39.2mpg fuel economy and impressive 189g/km CO2 emissions.

Although supple at a cruise, continuously variable damping keeps roll at a minimum when the pace increases.

The XJ feels biddable and accurate despite its 5.3-metre length.

Luckily, I was joined by a motoring hack colleague on my test drive which meant that I was also able to sample life as a back seat passenger.

In the long wheelbase car this cavernous space was developed to appeal to the emerging Chinese and Russian markets, where the passenger is king.

Air conditioned or heated settings for the leather seats, climate control and a pair of veneered fold-down desks bring a British Airways Business Class feel.

Thankfully the driving experience up front ensures that your cabin crew should be somewhat happier than those at 40,000 feet.

Now to the track...

I’m feeling fully relaxed after my passenger ride in the XJ but it’s soon time to install myself behind the wheel for a few fast laps of Silverstone’s Stowe Circuit.

The XJ might not be suited in its scale or luxury status to track driving, but it isn’t ill-prepared for such an application.

An all-aluminium monocoque chassis helps make the XJ the lightest car in its class—some 150kg lighter than its closest rival—and with its adaptive suspension and a an electronically controlled rear differential, traction should be predictable, even in the rain.

Torque from the V6 diesel engine makes a welcome companion and, as the rain comes down, the rear scrabbles for traction out of tighter corners.

There’s a sense—to be expected with a massive 3,157mm wheelbase—that the rear end reacts a moment after the front end turns in but the XJ is corners with minimal lean.

The six-speed gearbox proves remarkably quick shifting and changes down helpfully as I brake into corners.

It’s an unusual sensation hustling the car which I had admired for its refinement and creature comforts moments earlier but in a place where any handling floors could be cruelly exposed, the XJ exhibits remarkable composure.

Whether anyone will ever choose to drive their XJ on track away from an industry test day is highly doubtful but the fact that the car copes so well in what should be alien territory shows the sheer depth of development that has gone into it.

One of Jag’s big-hitters from marketing had told me that the marque had targeted excellent interiors as the key to their future success some time ago, but with styling and dynamics like those demonstrated to me last week, it’s obvious that the quality runs much deeper.

There’s no limo I’d rather be dodging a terrorist threat in.....well, maybe that supercharged five-litre version.