Jaguar XK/R

The XK is a fine car but hasn't reached its potential. Solution? Add supercharger. The extra oomph turns the new XK/R into a real Jaguar, leaving John Simister purring with satisfaction

Price: £67,495 (coupé), £73,495 (convertible). On sale now
Engine: 4,196cc, V8 cylinders, 32 valves, supercharger, 416bhp at 6,250rpm, 413lb ft at 4,000rpm
Transmission: six-speed automatic gearbox, rear-wheel drive
Performance: 155mph (limited), 0-60mph in 4.9 seconds, 22.9mpg official average
CO2: 294g/km

"An XK with the volume turned up" - that's how Mike Cross, the man charged with making Jaguars feel as Jaguars should, describes the new XK/R.

Its parts are Jaguar XK plus a supercharger - and the whole is a car that stands a chance of making its relative within Ford's Premier Automotive Group, the Aston Martin DB9, look just a tad extravagant.

The Aston costs £106,850 and has a 450bhp V12. The Jaguar costs £67,495 and has a 416bhp V8. That's enough power for most needs, you would think, especially as it is matched with very strong lower-speed pulling ability. The shape of both cars is the work of the same designer, too: Ian Callum, Jaguar's design director for the past few years.

We like the new XK with its all-aluminium body and structure. So do customers, who have bought it in encouraging numbers since its launch in January, adding positive vibes to the slightly negative aura currently surrounding Jaguar as a company. (Is the uncertainty a fine piece of unintentional sabotage by Ford just as news from Jaguar was getting much better? Who knows?)

Yes, the XK looks good in a modern but clearly Jaguar way. It's fast and fun to drive, with great handling and a terrific automatic transmission, and the required credibility is achieved. If there's a flaw, it is that the V8 engine's 300bhp requires some effort to extract: its low-speed pull is not fantastic. But it sounds sweet and revs with glee, so it's not a big problem.

Drive the new R version, though - discreetly toughened up with its mesh grille and its bonnet vents and its deeper valances - and you drive a car properly in touch with its potential. You're ambling along with 3,000rpm showing on the rev counter, you're in fourth gear (selected manually, so in fourth it will stay despite what happens next), and you floor the accelerator. A torrent of torque flows to the rear wheels and the Jaguar leaps forward, under perfectly metered control but crackling its crisp exhaust beat in obvious enjoyment as the supercharger hums its background whine. There's nothing wrong with the way this XK goes. From a standstill, 60mph is yours in 4.9 seconds.

I'll stay in manual mode for a while, because here are some tempting mountain bends. Brake for the corner; the XK/R has bigger, stronger brakes that feel very reassuring. Flick down from fourth gear to third with the left-hand paddle-shifter; the XK/R shifts gears more quickly than the XK, but can still execute the ratio change with perfect smoothness. Now turn; the adaptive suspension damping system momentarily stiffens the rear dampers 0.3 seconds before the fronts, which helps the nose point into the corner. Apply power, hold tight, feel the XK/R cling tightly to the road as it hunkers down and aims for the next bend.

This is a big car but a very wieldy one, with quick, positive steering which feels a little heavier, "meatier', more natural, than that of the regular XK. You can feel variations in weighting as the grip changes under the front wheels, which means that reality isn't completely filtered out by a wall of power assistance, as is too often the case nowadays.

I love this car's gearbox. It's the ZF six-speed automatic as used by many high-end car makes, but with Jaguar's own programming, which is better than anyone else's. Jaguar could have made the automatic gearshifts completely "seamless", so you would sense nothing more than a change in engine note, but the company considers that drivers prefer the feeling that something mechanical is happening during a gearchange. So there's the merest pause in power - never abrupt, just enough to feel right.

Even better, though, is the way the sequential manual shift works. It's quick, definite and obedient, and like a Ferrari's "F1" gearbox (which is a "robotised" manual rather than an automatic with a manual mode) it gives the engine a blip of revs for a perfect downshift before fully engaging the lower gear. So-called Tiptronic-type manual shifts in automatic transmissions usually feel too remote and disconnected, often not doing exactly what you want the instant you want it, so I find that I often don't bother using them after about 10 miles of experimentation. They're too annoying. But the XK/R's is a joy, encouraging you to shift up and down the gears just for the fun of it.

There's also a Sport auto mode, which makes the gearbox more responsive so that it "kicks down" more readily. This is less satisfactory, because the sudden shifts can be abrupt and unexpected. Regular auto is plenty responsive enough.

Jaguar understands how a sporting car's suspension should feel better than any other car maker, in my view. The XK/R feels firm, but it's never, ever harsh over bumps. It still "breathes" as a Jaguar should, but simply feels more planted and more responsive at speed.

And here's an extraordinary thing. Both the coupé and the convertible XK/R have the same suspension settings, whereas most convertibles are more softly sprung than their closed siblings to help disguise their floppier structures. Such is the XK/R's bodily stiffness that it's the most solid-feeling, all-of-a-piece big convertible I've ever driven.

Would I have the convertible over the coupé, then? No, because the coupé is still the purer concept and the sharper drive.

At its price point, the XK/R is in an intriguing position. It's cheaper than, say, a Mercedes-Benz SL500, yet really it's a rival for the faster, harder-edged SL55 AMG. Similarly, it's a match for a Porsche 911 Turbo, but with the advantage that its pleasure potential is more accessible because it always feels keen. The Porsche, by contrast, feels torpid unless and until you let it rip, by which time your licence will be in grave danger.

It seems strange to declare a £67,495 car a bargain. But in its context, Jaguar's delicious XK/R is exactly that.

The rivals

BMW M6: £81,760

Mad 500bhp V10 engine sounds rather like a previous-era Formula One car, but sequential gears can't match the Jag's auto and it's a harder car to flow with.

Mercedes-Benz SL55 AMG: £97,265

Big supercharged V8 delivers 500bhp and a menacing exhaust note; SL comes as standard with a folding metal roof. Lacks XK/R's dynamic finesse, though.

Aston Martin DB9: £106,850

Looks luscious, sounds fabulous; spoiled by harsh ride, road noise and unco-operative manual transmission. Improved as an automatic, but the XK/R is a better car.