After the ‘evolution’ in design terms that the new Jaguar XK represented when it was unveiled in 2006, the S-TYPE replacement, the XF – first shown in 2007 and on sale from early in 2008 – marked a far bigger step forward for the brand. It was, in sheet metal, the revolution that Ian Callum, Jaguar’s design director, had long promised. When it was unveiled he said: “This car is modern. We have to make quite a definitive statement as to how we are moving forward. I believe that when this car is launched, it will be the most modern in its class.”

He was right too. Though still a ‘three box’ saloon, the XF didn’t look like it; low and lithe, its profile is coupe like – which was quite intentional. Its deep-set mesh grille also ushered in a new saloon ‘face’ for Jaguar, while its interior was a world apart from what had gone before. Not in terms of materials, wood and leather still being there in abundance should the customer so choose, but its styling was very contemporary and a bold departure for Jaguar. And there were plenty of ‘surprise and delight’ features too.

Open the door, sit down in the driver’s seat and – courtesy of keyless start – the start/stop button on the centre console would pulse red. Press it and as the engine fired, a rotary gear selector would rise from that same centre console – there was no gearstick – while the dash vents, closed with the engine off, would rotate open to face the driver. Touch sensitive controls for the interior lights and glovebox, plus phosphor blue illumination were some of the other ‘delights’ – and they did just that.

Three specification levels were offered – Luxury, Premium Luxury and then one specifically for the range-topping SV8 model. All, though, were well equipped with features such as touch screen sat-nav system standard on every XF. Under the bonnet, customers could choose from four power units, all carried over from the S-TYPE: 2.7-litre V6 diesel; 3.0-litre V6 petrol, 4.2-litre naturally-aspirated V8 and, for the range topping SV8 only, a 420bhp supercharged version of the latter.

Each engine drove through the six-speed ZF automatic unit, by then commonly used in Jaguars, and just as it did in the XK the box’s installation in the XF included a sequential shift facility via steering wheel mounted paddles. The suspension system was also a development of that used on the XK, which meant unequal length wishbones at the front and a multi-link rear setup, both of which were sub frame mounted for maximum refinement. The diesel and naturally-aspirated petrol models had a passive damping system as standard, while the SV8 used the latest generation of Jaguar’s well-proven Computer Adaptive Technology Suspension. Braking was via 326mm discs front and rear on all but the SV8, that car using bigger 355mm front discs.

On the road the XF went as well as it looked. Not only were its dynamics excellent but it was well screwed together and, in SV8 form, very quick indeed. However, less than a year after it went on sale, some far quicker versions were to appear.

Still in development as the XF was launched, early in 2009 Jaguar’s next generation of diesel and petrol engines appeared: a 3.0-litre V6 twin-turbocharged evolution of the previous 2.7 diesel, and an all-new 5.0-litre petrol V8 in both naturally-aspirated and supercharged forms (the existing 3.0-litre petrol V6 was also retained).

The 3.0-litre diesel was not only cleaner and more economical than the outgoing 2.7-litre unit, it was significantly more powerful too. Available in 240bhp ‘standard’ and 275bhp ‘S’ spec, the engine used an innovative ‘parallel-sequential’ twin-turbo system with Honeywell-Garrett turbos. Whereas the old unit had two identically sized small turbos, the new engine used a larger primary variable vane turbo on its left side, and a smaller fixed-geometry turbo on the right. The exhaust manifolds were linked via a crossover pipe that features a shut-off valve before the secondary turbo. In low speed running this valve remains closed ensuring that all the exhaust gasses drive the primary turbo. When required the shut-off valve in the crossover pipe opens thereby sending exhaust gasses to the secondary turbo which spins up and comes on boost in less than 300-miliseconds. It’s quite a bit of kit – and in either specification returned a claimed combined figure of 42mpg.

Though obviously not as fuel-efficient as the diesel, the direct injection 5.0-litre petrol V8s were the most advanced in their class, and with power outputs of 385bhp and 510bhp in naturally-aspirated and supercharged form respectively, gave the XF some serious go… In fact, so quick was the supercharged engine that the previous SV8 designation was dropped, and the ‘R’ suffix made its first appearance in the XF line-up, the XFR topping the new range. That range still started with Luxury and Premium Luxury spec cars, but an even plusher ‘Portfolio’ spec was also introduced, this only being available with diesel V6 or naturally-aspirated V8 power. The supercharged XFR had a spec all of its own which included the same adaptive dampers used on the 5.0-litre XK/XKR, a quicker steering rack, and a trick electronic limited-slip differential.

Despite the upgrades under the skin, the exterior appearance of the XF remained largely unchanged at this point – though the XFR had a meaner body kit – but in 2011 that changed as the entire range was given a facelift. On the very latest cars new, slimmer LED headlights are sandwiched by a new front bumper and bonnet to give an even prettier front end, while the flanks feature revised wing power vents, and the rear end new tail lights. Still contemporary, Jaguar’s first saloon to represent its new design language, is now more modern still – and there’s even a four-cylinder turbo diesel ‘eco’ engine capable of 53.2mpg driving through an eight-speed auto ‘box.