Jaguar XKR

The Jaguar XKR was always fast, but the latest version – lighter and more powerful – is out of this world

If you are a true car enthusiast, then you might feel frustrated at waiting so long for our report on the latest Jaguar XKR. So think of it as a build-up to a climax; Jaguar has launched three impressive new engines this year, resulting in numerous new permutations of XFs and XKs, and we could hardly report on them all in quick succession.

The supercharged XFR and the twin-turbo diesel XFD we have covered. The cars powered by the non-turbo V8 we have not, because in the XF's case you're better off with the excellent (and frugal) diesel, and in the XK's case ... well, let's just say the XK V8, fine car as it is in many ways, has strayed from what a grand-touring Jaguar should be.

I'll return to this theme later, but let me first introduce the XKR. I was blown away by the XFR saloon, transfixed by the torrent of effortless energy on tap and the feeling of unflappable security it imparts when travelling quickly on challenging roads. The XKR coupé is about 140kg lighter than the XFR. So fireworks are guaranteed.

Out on the public road I did not reproduce the tyre-smoking cornering style the XKR allows to those able to afford replacement rubber on a regular basis, but on the test track I did indulge my curiosity. First, though, the new XKR as road machine, updated with sharper detailing and the rotary transmission selector from the XF range. Its new V8 engine, exactly five litres in capacity and able to generate 510bhp as well as 461lb/ft of pulling power, has direct fuel injection and the promise of rather better fuel economy than its 4.2-litre, 416bhp predecessor. That peak pulling power arrives at just 2,500rpm and doesn't abate until 5,500rpm.

The Jaguar XKR was a very fast car before, but now it's close to bombastic. All that energy and the relatively light weight, that comes from the aluminium chassis and body structure, make the XKR feel like a car in which mass has been magically spirited away, as if it's being driven on the moon rather than planet Earth.

The engine's efforts are channelled through one of the best automatic transmissions made today, a six-speed unit which can either be left to its own, well-judged devices or controlled manually via paddle-shifters behind the steering wheel. What makes it so good is that the automatic mode is always smooth, unlike that mode when applied to a "robotised manual" transmission as offered in Aston Martin V8s, Lamborghinis, some Maseratis and Ferraris and the Audi R8, yet in manual mode it is virtually as responsive as those cars' systems and gives a similarly well-judged blip of the throttle to smooth the downshifts.

More than ever before, the XKR feels like a supercar of an ability and sophistication far beyond its price of between £72,400 for the coupé to £78,400 for the convertible. But with the new adaptive damping system for the suspension, continuously variable instead of switching between two settings, comes a firmness over bumps at the upper end of what a Jaguar owner's expectation range would consider tolerable.

That's acceptable for the hardish-core XKR, but the regular XK now shares much of this firmness and the much-admired ability of a Jaguar to "breathe" over bumpy roads has been sacrificed. Anyway, switch the "Jaguar Drive Control" to Trac DSC, and the stability systems are loosened and the XKR's "active" differential can show its metal's mettle. This, like Ferrari's E-diff and a similar Audi system, alters the torque-split between the rear wheels to ensure they always help the car to aim in the optimum direction without triggering the slowing-down effect of a stability system which relies on brakes.

On the road, it makes the XKR wonderfully interactive with your steering and accelerator inputs. On the track, the DSC still intervenes too readily so you turn it right off. Then you can drift the XKR as though it's an old-fashioned racing car, and make as much tyre smoke as you dare. All that torque, all that subtlety of control, all that beauty: the XKR is hardly cheap, but nothing comes close for the money.

THE RIVALS

Aston Martin V8 Vantage: from £83,191. Now with 4.7-litre engine and 420bhp, Vantage remains a beautiful car with enjoyable handling. Harder work to drive than XKR.

BMW M6: from £83,700. At 507bhp, comes close to Jaguar power, but uses V10 engine and high revs. Transmission complex and not always smooth, sound amazing, fun considerable.

Maserati GranTurismo S: £88,005. V8 with 433bhp, hot on pace and aural drama. It's the car the GranTurismo should have been from the start, but lacks XKR's musclepower.