THE Poms may be much maligned at times, but when a car like the Jaguar S-Type R comes along you know there's plenty of smarts and guts still residing up north.

Okay, so Jaguar is now owned by Ford and the purity of the Coventry cat has been degraded over recent years by the curse of commonisation and economies of scale. But on the plus side the Yankee dollar has enabled Jaguar to negotiate some tough times and given these British craftsmen the opportunity to build a car like the S-Type R.

Sitting at the top of a thoroughly revamped S-Type range, the R is a true rear-wheel drive Euro sports sedan in the mould of the BMW M5: great power, poise and prestige.

Like the rest of the range it benefits from the comprehensive mid-life update bestowed on S-Type this year. From our experience so far, the changes - which make a significant impact on all aspects of the car bar the retro exterior - have elevated the S-Type from good to great.

And that epithet applies to no model more appropriately than the S-Type R.

R is Jaguar's high-performance branding - what M is to BMW and AMG to Mercedes-Benz. Jaguar also builds the wonderful XKR and XJR as well as offering a range of R high-performance accessories, but the S-Type is the latest and greatest.

At the heart of the matter is a double overhead camshaft 32-valve all-alloy 4.2-litre version of the AJ-V8, which first saw service in the S-Type as a 4.0. For the update it's not only its capacity that has been addressed because the normally-aspirated unit that goes into the SE and Sport models is virtually all-new.

But the R goes a step further, adding a belt-driven Eaton supercharger, forged pistons with oil cooling jets, twin intercoolers for the supercharger and revisions to the air inlet systems. The result is 298kW at 6100rpm, 553Nm of torque at 3500rpm, a claimed 0-100km/h dash time of 5.6 seconds and an electronically limited top speed of 250km/h.

Attached to that is the ZF 6HP26 six-speed fully adaptive automatic transmission. Only previously seen in the BMW 7 Series luxury car, it's the only transmission choice for the R - the opposite of BMW's M5, which only offers a six-speed manual transmission here.

The auto is mated to Jaguar's unique J-gate shifter, which continues to draw its critics and fans, but continues to be refined now with manual shift-by-wire changes. There's also a Sport mode to drive the changes right to redline.

Coping with all this power and potency is a sports version of the standard and virtually all-new double wishbone front and substantially revised multi-link rear suspension. There are stiffer springs and electronically controlled dampers called CATS (Computer Active Technology Suspension), with front and rear rates automatically varied according to speed and cornering position.

There's plenty of other electronic support, with traction control, dynamic stability control and even panic assist braking as standard. Surprisingly, though, considering the immense power, the R misses out on the simple mechanical support of a limited-slip differential.

All S-Types have a 10 per cent stiffer body structure, but the R goes further by having a solid rear bulkhead for added rigidity, eschewing the split-fold rear seat offered with the rest of the range.

Providing the stopping power are Brembo brakes with braided hoses, four-piston aluminium calipers and a high-capacity booster. Keeping it all in contact with the road are 18-inch Zeus alloy wheels, mated to ContiSport tyres measuring 245/40 front and 275/35 rear.

Inside, the makoever continues with a substantially revised driver's environment. The ovoid shapes and green neon are gone, replaced by the full sweep of grey birdseye maple across the dash that Jaguar calls the "Spitfire wing", interrupted only by a large and familiar vertical centre console arrangement which is evocative of other members of the Jaguar family.

Leather trim, new seats and a comprehensive standard safety and comfort equipment list complete a pretty impressive package. New features include a nifty electronic park brake that is operated via a tab behind the J-gate shifter, side curtain airbags and optional electronically adjustable pedals.

It's a lovely environment in which to operate a wonderful car - and it's not that good simply because it's fast. It's the way it goes about it.

Tramp the throttle hard and power and torque meld into an irresistible wall of urge, all the while backgrounded by a delicious, rising whine from the supercharger and the sort of chattering only four cams, eight pistons and 32 valves can produce.

There's no detectable break in this power rush at any point in the rev range between idle and redline. It's intoxicating, completely accessible and a substantial danger to your license, so easy is it to venture to speeds highly illegal anywhere in Australia except the Northern Territory.

But it's not the engine alone achieving all this. Due tribute must be paid to the ZF gearbox, which tames and translates the engine's message. There's no bump-thump, no shilly-shallying up and down the box and certainly no indecisiveness.

The greatest delight of the ZF is not that it works so well when pressing on - which it does, virtually eliminating the need for manual use of the undoubtedly improved J-gate shifter, such is the level of its intuitiveness - but that the car is so damned useable at subsonic speed.

Around town and in heavy traffic there's no grumpiness, no hesitation and no heaviness. It simply trundles around as much at ease as the base 2.5 S-Type or any one of many other thoroughbreds we could name. Stunningly impressive stuff.

All this is beautifully complemented by the chassis, which manages to pull the same conjuring combination. Subtle, controlled and sporting on the open road, yet still not too tightly wound to make progress uncomfortable on Australia's chopped out roads. It's not as supple as an SE, but the latest iteration of CATS brings it pretty close.

Despite its 1800kg weight, the R steers impressively, changing direction much more nimbly than you would expect. Only the biggest holes tend to unsettle and send uncomfortably loud crashing noises through the cabin. Significantly over-enthusiastic throttle applications can also get the rear-end breaking away, but the electronic aids pull it all back into shape before disaster strikes.

The brakes and tyres wrap up the package, offering superb levels of grip and control.

The negatives are few and the same long-documented faults of S-Type that not even a makeover this comprehensive could fix - that cramped interior, small boot and restricted vision. And there's that reliability bugbear still around too because our R lost a cooling fan, causing a major haemorrhage.

Despite that the R deserves to be compared with the greats such as the M5. And some media around the world already have. The verdict? Even the notoriously parochial British gave the nod to the German car for sheer sporting excellence.

We tend to agree with that call. But we'd still happily park an R in our fantasy garage. It's sheetmetal proof the Poms can still build great cars.