Jaguar XJ 5.0 V8 Supersport

What is it?

You’re looking at the quickest version of Jaguar’s new limo, but it’s got a different name. There’s no Jaguar XJR in the new big-car range, even though the outgoing car had one. It’s allegedly because the marketing types reckon this car’s sheer size - you can get it in both short and long wheelbase versions - limits its outright sportiness in comparison with the XKR and XFR, and possibly because the whole ‘R thing’ may now be under review, given that Honda and Volvo, among others, use much the same nomenclature.

However, far be it from Jaguar not to provide a top-performance version of any new model. This quickest XJ is a 503bhp supercharged V8 which develops more torque than any other model, even the diesel, and which the figures say can hurl you from 0-60mph in just 4.7sec, which is not far short of a Ferrari’s time. Top speed is still limited at the usual 155mph, though the car would doubtless be good for 170mph-plus in ungoverned form.

What's it like?

Despite the extra potential, the most remarkable thing about the Supersport is its similarity to the rest of the XJ range; it uses the same tyre size, the same suspension bushes and rates, the same controls and instruments.

The only differences are some interior trim details (such as a leather roof lining) and an ‘active’ limited-slip diff, similar to that used for the XK and XF models. It employs electronically actuated brakes on its output shafts to improve cornering traction and aid agility. Jaguar suspension engineers insist you can feel the difference, between “slippery and no slippery” but it’s a faint difference, simply because the standard car sets such high standards, and has impressive traction-keeping gadgetry of its own.

On the road the car’s 270bhp-per-tonne performance is usually discreetly deployed. True, the car has prodigious low-speed thrust, but unless you use wide throttle openings the engine noise is not much more than a V8 murmur.

When you’re really use the power (handy even in motorway traffic for threading the car into gaps it would otherwise miss), the sound changes to that of a pure performance car, just as with the two smaller R models. The thrust is the same, too, not least because this car weighs slightly less than an XFR. This is a light car for its power, and feels it.

What is noticeable, though, is the extra agility of the short wheelbase XJ, which turns a little more sweetly, but maintains its line just as accurately. And given the extra nose mass of the V8, it seems to ride just a shade more quietly over some noisy surfaces, too. Like all XJs, it feels to have been carefully honed: Jaguar is determined to lose nothing to its opponens on refinement.

Should I buy one?

It’s worth pausing before you do: some Jaguar people say the normally aspirated V8 is now just about as quick as you need a car to be. And this is the priciest XJ of all; you pay £87,455 before options, or £90,455 if you want the extra five inches of rear room.

Still, all that power and torque is seductive, and almost too easy to deploy. Against the opposition, and looking at its performance and standard equipment, it’s almost a bargain.