Jaguar’s XJ has been given a bit of a makeover. However, you might not notice the new LED headlights, larger grille, revised rear bumper and new tail lights and even the improved luxury and extra tech might pass you by because you’ll likely be too busy revelling in how beautifully the big cat drives.

As subtle as they are, however, those revisions are crucial because the competition has moved the game on significantly in the six years since the XJ was thrust into the limelight so the addition of Jaguar’s InControl Touch Pro service, which is the company’s upgraded infotainment system, is very welcome.

It’s important, of course, that these improvements are thoroughly explored and examined so I arranged a test drive. Someone's got to do it after all and so an XJ in R-Sport trim and with a 3.0-litre V6 diesel under the bonnet offering improved economy, fewer CO2s and greater flexibility duly arrived.

It may be getting on a bit but the styling still retains a degree of the wow factor, particularly in the Glacier White paintwork my test car arrived in. It’s a big car but there’s not an ounce of fat on its body. It’s taut, muscular and primed for action. Unlike most limousines, even in its most basic configuration, this is a car that demands to be driven, not be driven in.

To add to its sporting credentials the R-Sport also gets a gloss black lower grille, front splitter, rear lip spoiler, gloss black rear valance and R-style side sills.

Inside Jet soft grain leather sports seats with red contrast stitching, Jet upper fascia, ivory suedecloth headling, piano black veneer and Jet carpets help set the R-Sport apart.

If that’s all a bit too subtle, the R-Sport logo appears on the steering wheel, tread plates and side power vents so there really is no excuse for forgetting what you're driving.

The only analogue instrument in the cabin is the small clock mounted in the centre of the dashboard. Jaguar have replaced the traditional dials with a digital display. It’s crisp, bright and easy to read but, as a demonstration of the advance in automotive technology, it’s not a patch on Audi’s virtual cockpit.

The infotainment system offers Bluetooth connectivity – including handsfree calling and audio streaming – plus DAB radio and digital TV so the Kardashians can keep up with you, wherever you are. It’s all plugged in to the excellent Meridian sound system.

The InControl Touch Pro system gives you access to compatible mobile apps via the 8in touchscreen when you connect your phone via the USB port. Optimised apps include contacts, calendar and music player.

Sat nav, as you’d rightly expect, is present and correct and works faultlessly. The graphics are refined and sharp, the spoken instructions easy to follow and the system easy to program.

The front seats are electrically adjustable and very, very comfortable.

Although there are roomier limousines on the market, there is still ample leg and headroom in the back, though there is a long wheelbase version if you prefer someone else to do the driving. Rear seat passengers get their own climate controls and there’s a secondary glass panel in the roof – in addition to the one above front seat passengers – to let more natural light into the rear if required.

The ride is on the firm side but I think that’s a fair trade-off for the excellent handling.

The XJ R-Sport offers grip and guile that will leave you believing you're driving something a lot smaller. The steering is consistent and beautifully weighted and the car turns in well despite its mass. There’s plenty of information being fed to the driver through the wheel, which is nice and linear as the inputs increase.

From behind the wheel the XJ feels small and, dare I say, nimble. There are times when the car is quick to remind you of its mass but for the most part it’s not impossible to picture yourself at the helm of the significantly sportier F-Type, such is the poise and finesse of the big Jag.

The on-the-firm-side ride doesn’t diminish the Jag’s long-range cruising capabilities either. Refinement is excellent. Passengers will feel properly insulated from the outside world whatever’s happening beneath the wheels.

The 3.0-litre V6 diesel is inaudible at cruising speeds and during hard acceleration returns a pleasantly encouraging muted rumble that sounds like anything but an oil burner. It’s a wonderfully flexible unit that doesn’t grumble whatever the request. It pulls hard from any speed – not with the brutal kick in the back like the supercharged V8 – but with a firm, insistent and consistent nudge.

Mated to the wonderfully slick 8-speed gearbox the whole package provides subtly searing pace, if you want it. Alternatively you can just sit back, relax, and watch as the world silently passes by.

The boot will swallow 520 litres of your luggage but I don’t imagine that is particularly high on buyers’ list of concerns when considering this car.

The XJ R-Sport is available with either the 3.0-litre V6 diesel fitted to my test car, or 344bhp petrol engine of the same size and configuration. There’s a significant drop in economy if you opt for the petrol version, although you do have the choice of all-wheel-drive.

The diesel offers excellent refinement, blistering pace and impressive fuel economy with ‘just’ 304bhp so unless you’re set on drive being sent to all four wheels, choosing it over the petrol version should be a no-brainer.

It’s a tougher call when it’s facing rivals from other manufacturers who have moved the game on significantly in recent times. However, while the XJ might have fallen behind in some areas, it remains a cracking drive, is beautifully put together and is still the best-looking car in its class.

It really is the cat's whiskers.

Jaguar XJ R-Sport

Price: £70,975

As tested: £72,510

Engine: 3.0-litre V6 diesel

Transmission: Eight-speed automatic

Max power: 304bhp

Max torque: 516lbft

Acceleration (0-62mph): 5.9sec

Maximum speed: 155mph (limited)

Urban: 39.8mpg

Extra-urban: 54.3mpg

Combined: 48mpg

Emissions (CO2): 155g/km

For more information visit www.jaguar.co.uk