By DAVID HASSALL 15 June 2009

JAGUAR’S exciting new XFR arrives in Australian showrooms in August priced from $208,450, undercutting its German super-saloon rivals by between $30,000 and $55,000.

First presented at the Detroit auto show, the highly-anticipated XFR – Jaguar’s fastest production four-door saloon – is powered by an all-new 5.0-litre supercharged direct-injection V8 engine developing 375kW of power (10kW down on the overseas model) and 625Nm of torque.

The new flagship of the revised 2009 XF model line-up effectively replaces the SV8, which was powered by the previous-generation 306kW/560Nm 4.2-litre supercharged V8 and joined the range shortly after the XF replaced the S-Type in Australia a year ago.

The XFR is the highlight addition to the mid-size XF range. Its engine is new, raising the stakes considerably over the old supercharged V8 in performance (power up 23 per cent and torque up 12 per cent) while also having better fuel consumption and emissions.

While enjoying a price advantage over the category standard-setting Mercedes-Benz E63 AMG ($238,956) and BMW M5 ($241,816), the heavier XFR falls slightly short of its normally-aspirated rivals in the performance department.

The Jag is said to sprint from rest to 100km/h in a lively 4.9 seconds, but that is 0.2s slower than the figure quoted at Detroit and is comfortably eclipsed by the 378kW/630Nm 6.2-litre V8-engined Benz (claimed 4.5 seconds) and the 373kW/520Nm 5.0-litre V10 engined Beemer (claimed 4.7 seconds).

Then there is the awesome Audi RS6, which carries a lot more weight than the others but overcomes that with brute force from its 5.0-litre twin-turbocharged V10 engine, which develops 426kW and 650Nm to push it to 100km/h in a claimed 4.5 seconds.

Weight figures for the four cars are revealing, with the M5 easily the lightest at just 1755kg, followed by the E63 AMG (1840kg) and XFR (1891kg) while the RS6 tilts the scales at 2035kg.

While buyers of these cars are probably not too concerned about fuel economy, the comparisons also make interesting reading, with the Jaguar comfortably heading the combined average list (12.5L/100km) from the surprising Audi (13.9L/100km), the Mercedes (14.3L/100km) and the light BMW (14.8L/100km).

As well as the general trim and specification changes introduced with the rest of the revised range, the first XF to carry the ‘R’ badge is distinguished by a number of design features.

The XFR front end features a larger lower grille with a black-finished mesh (although the upper grille is still chrome) between outboard chrome-outlined air intakes, while the unique bonnet carries a pair of louvres like those on the XKR.

Other styling touches include sill extensions, a new exterior mirror design, four chrome tail-pipes, a body-coloured lower valance on the rear bumper and a boot-lid spoiler that Jaguar claims has a significant aerodynamic effect and, combined with the new front bumper, provides a better balance and high-speed stability.

Jaguar claims the XFR is the only car in its class to offer 20-inch alloy wheels as standard, and the new Nevis seven-spoke items are embossed with the words “Jaguar Supercharged”.

The ‘R’ logo appears around the car, including the boot, the silver-grey brake callipers and, of course, the interior (including the sports seats and leather-bound steering wheel).

XFR-unique cabin details include a new dark oak veneer, 18 and 14-way front seat adjustment, a dark mesh aluminium finish fascia and red instrument pointers. And, as part of the XF’s regular “driver handshake” sequence at start-up, the ‘R’ logo appears on the central touch-screen.

The standard ZF six-speed automatic transmission is a shift-by-wire unit operated via steering wheel paddles or the XF’s iconic centre console dial, which pops up as part of the handshake sequence, and has been upgraded for the XFR with additional clutch plates and an uprated torque converter.

Steering has also been revised for the XFR with a fast-ratio rack while the brakes are naturally the largest fitted to the range, with 380mm-diameter internally-ventilated discs at the front.

But the major chassis change for the XFR is the standard continuously variable electronic damping system called Adaptive Dynamics and Active Differential Control (ADC), which electronically rather than mechanically alters the power delivered to each of the driven wheels according to road conditions and throttle application.

The differential is operated by an internal electric motor and ‘ball-and-ramp’ mechanism, and contains a multi-plate clutch that transmits torque to the wheel with most grip. Jaguar said the multi-plate clutch assembly was designed to prevent excessive differential slip, but differed fundamentally from a conventional traction control using the brakes to counter slip after it has occurred.

Jaguar claims the latest active damping system, which automatically adjusts the suspension settings according to road conditions and driving behaviour, analyses induced body motions one hundred times a second and has a smaller number of steps in the damper settings than earlier systems.

The new direct-injection V8 engine is more compact and has an alloy block with cast-iron liners, aluminium heads, forged rods, a sixth-generation Roots-type supercharger and twin water-cooled intercoolers.