THERE’S no mistaking the new Jaguar XJ. The trademark styling cues are still all there, despite an almost revolutionary change in its design to attract younger buyers.

That means the expansive grille, big wheels, low-slung profile are all present and correct, but the XJ of today is a world apart from its predecessors.

Officially the XJ is a four-door saloon, but the clever people at Jaguar have designed it in such a way that it looks coupe-like in profile – a clear statement of the car’s performance potential.

Slide down into the supersupportive leather seats and the XJ’s cabin replicates the wow factor of the sleek exterior. With its slim window line, the XJ feels snug, with a high shoulder line leaving you cocooned in luxury.

The XJ aims to make its occupants feel special and comfortable, and it does so in fine style. Opt for the long wheelbase version and you get extra legroom for your rear passengers.

Subtle enhancements to the cabin are now available for this year’s XJ range to allow greater personalisation and flexibility of use.

A new rear comfort pack offers seats that now feature electric adjustment of the backrest recline angle, four-way lumbar support and a massage function. Increased comfort is also provided by new winged headrests, footrests and the ability for the front passenger seat to be stowed away forwards when unoccupied to increase legroom even further.

On the long-wheelbase Portfolio derivative a new executive pack transforms the rear of the XJ into a high-speed mobile office space with the provision of fold-down laptop trays and an electric rear sunblind for increased privacy. The package also includes upgraded carpeting, combination wood and leather steering wheel, gloss wood veneer choices and chrome mirror housings.

The superb cabin remains hushed even when the diesel engine is working hard, and there’s a pleasing rasp from the exhaust when doing so. The Drive Selector also allows you to switch out of standard mode into dynamic or winter, with adjustments made to steering weight, gearbox mode and suspension stiffness – all the better to match your mood.

Even in standard mode, the XJ offers a firmer ride than the competition. It can still waft along and insulate you from the worst that the road has to offer, but this is a car you buy because you want to be behind the wheel and not sat in the back. Tweak it into dynamic mode and you can push the XJ hard, with responsive, light steering and fine balance. It’s as good at playing the sports car as it is at pampering you on the way home.

The touch-screen system results in an uncluttered dashboard, and the now-standard Jaguar gear selector does its bit to keep fussy controls to a minimum. There is no shortage of toys either. The clever dual-view screen allows the passenger to watch a DVD or television while the driver can only see information and the satellite navigation display, the seats have the option of heating, ventilation and massage, and the top-of-the-range Bowers and Wilkins audio system’s sound is epic in its clarity and power.

If it is one of the XJ’s principal aims to make its occupants feel special and comfortable, then it does so in fine style. There is no finer cabin in this price bracket.

Taking this a step further is the aforementioned long wheelbase variant. There has been some disquiet over the amount of legroom afforded to rear seat passengers in the standard length XJ. This issue has been fully resolved in the long wheelbase variant, and for many this car will be the default choice.

Furthermore, on the road you would never know you were driving the longer XJ. This car is just as responsive and agile.

But the car’s ability to waft and glide you to your destination in reality comfort and luxury is only half the story. As with the previous generation, this XJ has an aluminium structure – 50 per cent recycled – which gives it a weight advantage over the competition, That’s good for economy and performance: the tested 3.0-litre V6 diesel version can achieve an official average figure of just over 40mpg – and during a week-long test I found that figure easily achievable.

When you consider that this car will also reach 155mph before a limiter comes into play and will soar from 0-62mph in 6.4 seconds, that’s a remarkable piece of engineering and design.

There’s no question that replacing the XJ was a hard task for Jaguar.

Expectations were always high and no XJ has been able to step out of the shadow of the original 1968 version – until now.

With a clever and considerate blend of technology and thoughtful but bold design, this new XJ is a welcome step forward for Jaguar.

And in long-wheelbase trim it’s better than ever.

It makes its more conservative rivals look positively dull.

JAGUAR XJ 3.0 V6 DIESEL PORTFOLIO LWB

PRICE: from £69,520.

ENGINE: 3.0-litre diesel unit developing 275bhp.

TRANSMISSION: six-speed automatic transmission, driving the rear wheels.

PERFORMANCE: maximum speed 155mph (limited), 0- 60mph in 6.0 seconds.

ECONOMY: 40.1mpg.

CO2 RATING: 184g/km.