First drive: Jaguar XK power boost

SIX years is a long time in the world of automotive styling, particularly when it comes to the luxury sports car segment, which is largely image driven.

So it's a credit to Jaguar that its XK range - the leaping cat brand's fastest selling sports car ever with more than 70,000 sales globally since the XK8's 1996 Geneva motor show release - is still one of the most beautiful shapes in modern motoring.

But when design does not advance, neither do sales. So when it came time for a reluctant late-life freshen-up of the XK8 and XKR coupe/convertible range before its all-new successor arrives in 2005, Jaguar's resistance to styling change for a model sold almost exclusively on the basis of style was both surprising and predictable.

Indeed, when the mildly facelifted 2003 XK line-up arrives in Australian Jaguar showrooms around late October after its Sydney motor show local debut, even Jaguarphiles will find it difficult to pick the visual exterior differences - which include subtly revised grille and lighting designs and new wheel and colour choices.

Although many customers may not notice them, the biggest changes to XK - apparently some 900 in total - have occurred underneath its sexy skin. XK8 models are now powered by the heavily updated 4.2-litre version of Jaguar's quad cam AJ-V8, which debuted in this year's facelifted S-Type medium sedan.

Stroked by 4mm from its previous 4.0-litre displacement via a different crankshaft, the revised engine also gets a stiffer block, oil-cooled pistons, new exhaust manifold, an air inlet "power door", new camshafts, small-pitch silent camchain, bigger cyclinder-head porting, updated fuel system and faster, vane-type variable cam phasing.

The result is four per cent lower emissions and noticeably more power and torque across the rev range, the peak figures now being an 8kW better 224kW at 6000rpm and 420Nm of torque at 4100rpm. In addition, the supercharged version of the uprated engine benefits from a new exhaust system delivering a better (but 10dBA quieter) note, resulting in a maximum of 298kW at 6100rpm and 553Nm at a lower 3500rpm.

In concert with XK's other big change - the addition of a segment-first six-speed automatic transmission built by German gearbox specialist ZF - the facelifted car realises significant gains in performance and driveability.

Employing 30 per cent fewer parts, weighing 8kg less and matched to a revised J-gate shifter with better definition, the smaller new transmission is more adaptive and responsive, and features improved shift time and quality.

The extra engine performance combined with a lower, more responsive first gear ratio delivers incremental gains in acceleration for the naturally aspirated XK8, 1685kg coupe versions which now accelerate to 100km/h a few tenths quicker in 6.4 seconds, while the 1775kg XK8 convertible completes the dash in 6.6 seconds.

Because most of its gains have occurred in the midrange, the supercharged XKR's 0-100 figures remain the same: 5.4 seconds for the 1735kg coupe and 5.6 seconds for the 1815kg XKR convertible. All models remain speed limited at 250km/h.

Elsewhere, all 2003 XK models now benefit from four new interior trim colours, automatic headlights, power-adjustable steering column and Dynamic Stability Control in addition to traction control. Jaguar's Adaptive Restraint Technology System is added to standard twin front and side airbags, and ABS with Emergency Brake Assist.

XKR models now get standard Xenon headlights with washers (optional on XK8), Brembo brakes (optional on XK8 only with 20-inch R Performance wheels) and Computer Active Technology Suspension.

All Australian XKs now offer the option of a built-in compass display for the electro-chromatic interior mirror and, joining S-class and 7 Series, radar-operated Active Cruise Control (good for a range of 150 metres and able to apply up to 25 per cent of brake force) with Forward Alert, and audible alert that can be used independently of cruise to warn of rapidly closing traffic.

R Performance options (pricing for which is yet to be announced) will continue to be offered for XK models, including a range of BBS alloy wheels and an Aluminium Pack including alloy instrument surrounds, J-gate fascia and door release levers, pedal pads and leather steering wheel and gearknob.

Meantime, the R Performance Handling Pack option for coupe models has been revised to offer a sportier steering and suspension tune, thanks to different springs and anti-roll bars, revised suspension bushing, lower ride height and revised steering assistance.

XK's new factory-fitted DVD-based satellite navigation system will not be made available in Australia because its former CD-based mapping system is not compatible.

Despite this and price increases of between two and 3.5 per cent - including a bigger gap between coupe and convertible models, and between XK8 and XKR models - Jaguar Australia expects the model update, advertising and exposure in the next Bond film to increase XK sales from around 80 this year to up to 100 in 2003.

The same 50/50 coupe/convertible model split is also expected - as is the high, 35 per cent female ownership - and, despite the XK8's increased performance, the XKR is still expected to comprise half of all XK sales.

"We don't expect the mix to change between XK8 and XKR - maybe a per cent here or there - because people at this end of the market aspire to the Jaguar image, not mere numbers," said Jagaur Australia CEO Danny Rezek.

New XK pricing:
XK8 Coupe $188,000
XK8 Convertible: $216,000
XKR Coupe $209,000
XKR Convertible $237,000

DRIVE IMPRESSIONS:

IT'S amazing what a difference just 200cc and an extra gear ratio can make.

Of course, that's over-simplifying what is a significant and highly effective V8 engine upgrade for Jaguar, along with the addition of a superb, class-leading six-speed auto from ZF.

Combined, they give XK the kind of performance and driveability that owners of current 4.0-litre cars could only dream of.

And while the supercharged XKR offers more of the bloodrush excitement it has become famous for - plus an equal increase in overall usefulness - the biggest gains have been made by the naturally aspirated XK8 models, which now offer a performance level closer to that of Jag's sports car flagship and make the extra $21,000 that little harder to justify.

Thanks in big part to the improved automatic transmission performance and lower final drive ratio (although fifth and sixth ratios are both overdriven, making for stratospheric top-end gearing), the XK8 engine now delivers a little more crisply and more obligingly, and still has that great bent eight note.

It's even more evocative in the convertible and after a day of touring English backroads, it is easy to realise the allure of a big, luxurious British sports car with lazy V8 responsiveness.

There's no doubt the XKR's abilities are considerably more formidable, particularly off the line and in its meaty, willing midrange, where it offers deceptively rapid progress even for a large, heavy two-door like this. And all the time offering excellent low speed ride attributes, a high level of interior comfort and a slightly more refined supercharger note and feel.

But the biggest surprise was the atmo car's high-speed ability. Just as stable, planted and confidence inspiring at speed as its supercharged sibling, at the fast Gaydon test circuit the XK8 was even faster than both XKRs on offer, creeping inexplicably away with ease to very near its 155mph (250km/h) speed limit - despite identical gearing. Perhaps it was the extra few kilos or the inferior aerodynamics of XKR's slightly wider rubber, but the XK8 was impressively superior in the hands of all who sampled it.

Of course, we're talking speeds that are highly illegal in all but one state of Australia, where the blown XKR will be the quicker device for point-to-point motoring. This is something all XKs accomplish with satisfying grace, offering immense levels of mechanical grip, well weighted and relatively communicative steering and a well balanced, taut chassis that has the perfect compromise between protective understeer and progressive oversteer.

New driver aids like stability control make for heightened confidence at the limit, but for our money the big Jag's braking performance should have been upgraded to match the extra urge. Sure, the XKR now gets standard Brembos, but the XK8 in particular felt more oriented to initial pedal progression rather than bite and caused concern on a couple of occasions.

Like the standard car's handling, braking is oriented more toward comfort than outright performance, but just because it's a stylish grand tourer that spends more time cruising boulevards than switchbacks, does not mean it should be this inferior to benchmark rivals like the Porsche 911.

Yes, the famously inefficient interior packaging - comprising the same high-mounted (fully electric, leather) seats, low roofline and tight legroom - and the dated, cheap looking soft-top stowing arrangement (which Jaguar says is a must to accommodate the golf bags used by most XK buyers) remain the same as before and would be regarded as inexcusable in any German equivalent.

But the XK still delivers in the critical area of style - in spades.

Throw in a considerably wider performance envelope, particularly in entry level XK8 coupe guise, a tighter drivetrain with more tractability and a number of handy new driver comfort tools - for not ridiculously more money - and this more serious XK is even more able to fulfill the tasks most owners will ask of it.