Jaguar XJ makes you proud to be British

The Jaguar cat has a grin on its face wider than its proverbial Cheshire cousin. It has been many a long moon since anyone has seen that, with more than a decade of watching the West Midlands car-maker through gritted teeth as it struggled with under-investment and a tired product range that still bore the mark of Sir Henry Lyons, decades after it should have moved on.

Many feared, myself included, that the 'brand essence' of Jaguar would be lost when it was finally sold by Ford – along with Land Rover – to Tata Motors. But since then the Coventry cat has gone from strength to strength on the back of two exceptional new models under the design leadership of Ian Cullum who joined Jaguar from Aston Martin. Both the XF and the newer flagship XJ have won more awards and accolades than Colin Firth and The King's Speech.

Latest financial figures reveal that Jaguar Land Rover has enjoyed a 400pc surge in profits, driven by booming demand from the newly-rich in India and China. The company shrugged off talk of economic gloom by making �275m in the final three months of 2010, up from �55m during the same period in 2009. The jump helped boost profits at Tata Motors to �330m. Tata is India's biggest builder of commercial vehicles as well. Perhaps the only small cloud on the horizon is that Tata says it has plans to build both Jaguar and Land Rover in China too, which must raise a few concerns among the 12,000 West Midlands workforce.

When I first clapped eyes on the XJ my initial impression was that from the outside it simply looked like a stretched XF. But on closer examination it is sleeker and sharper, with an aggressive coupe silouette. A panoramic glass roof is an integral part of the design concept, enabling the car to have a lower, more streamlined roofline, while dramatically enhancing the feeling of light and space inside.

Enter the cabin and you enjoy the lap of luxury, but unlike the XF there a couple of styling cues – the analogue clock and the oversize air-conditioning outlets – which hark back to a past era. While it perhaps does not feel quite so spacious as its German rivals it's a lot more stylish and interesting.

Jaguar proclaims: 'The new XJ is a thoroughly modern interpretation of the quintessential Jaguar. It is the most emphatic statement yet of our new design direction.'

But before I get into more detail what are the 'sexy' bits about the XJ? Well, just like the XF, the rotary gear change knob smoothly rises from the centre console on start-up and gears can also be selected via paddles behind the steering wheel. But more surprising is the 'virtual instrument panel' so the main dials in front of the driver are TV images rather than physical bits of kit. I thought it was a tad gimmicky at first, but quickly got to see how useful it was when, for instance, the rev counter disappeared to be replaced by different information at the push of a steering column switch.

But the best bit was the eight-inch dual view touch screen at the centre of the console that can project DVD movies or TV programmes to the passenger while on the same screen the driver can only see vehicle functions or follow satellite navigation.

Jaguar offers four engines in the XJ – three 5.0-litre petrol units of differing power output and performance – and a 3.0-litre diesel equipped with twin sequential turbochargers, the more sensible choice if you want to help make the Earth's oil resources last longer.

Sometimes the most sensible engine in the line-up can also be the most dull. And yet this diesel V6 – that will see something like 75pc of all XJ business in the UK – is quite brilliant. Exceptionally quiet, it's fast too with 60mph coming up in just six seconds and a top speed of 155mph.

But the bonus is fuel economy, thanks partly to the lightweight aluminium vehicle architecture. I covered around 500 miles in the test car, over a variety of everyday routes, and it returned 38.9 mpg. Had I not been occasionally seduced by the stunning performance of the diesel engine, I reckon it would have easily nudged the other side of 40mpg.

The V6 thumps punches 275bhp and a satisfying 443ft.lb of torque, which is on tap all of the time. The six-speed automatic interprets the power perfectly and if you feel the need you can 'go boy-racer' and switch to the 'track' setting that sees the dials turn red, and adjusts various car-related parameters and paddle-operation of the gearbox.

In a previous life, the XJ was renowned for its supremely comfortable (some might argue sloppy) ride. In this respect the new XJ is a little surprising, because it's a bit firm around town if I am being honest. But the precision this tautness produces on country roads is worth it. The steering is accurate, the brakes sublime, with most noise coming from the 20in wheels with which the test car was shod. Despite its size, the XJ does not feel and handle like a big car, proving more nimble than you might expect.

There are three trim levels offered on the new XJ, all of which start at luxury and get progressively more luxurious with more kit. The test car was a range-topping Portfolio model, with standard wheelbase, and dripping with just about every extra known to motoring man. Yet despite this Jaguar did come up with a few extras including a �500 TV and an �1,800 driver assistance pack that features adaptive cruise control with forward alert, blind-spot monitor, advanced emergency brake assist and active seat belts. Still, if you can afford the �66,500 for the standard Portfolio, why not splash out a couple of grand more!

So what's not to like about the new XJ? Well I am not convinced by the rear-end look, and the space for rear passengers is not as generous as you might hope for in a car of this size – Jaguar does make a long wheelbase version, though.

Aside of these minor points it is quite brilliant and makes you proud that it's British-built and designed. In soccer parlance it's West Bromwich 5, Stuttgart 0.

JAGUAR XJ 3.0 D V6 PORTFOLIO

Price: �66,500 (range �55,500 to �94,000)

Engine: 3.0-litre, 275PS, V6 turbo diesel

Performance: 0-60mph 6.0 seconds; top speed 155mph (electronically limited)

MPG: Urban 29.6; extra urban 50: combined 40.1

CO2 rating: 184g/km

Benefit-in-kind tax rate: 28pc

Insurance group: 49 (out of 50)

Warranty: Three years/unlimited mileage

Will it fit in the garage? Length 5,122mm; width (including door mirrors) 2,110mm; height 1,448mm