JAGUAR is adding even more big cat appeal to the must-have' XKR range with the unveiling of the all-new special limited edition Portfolio model.

The XKR's already powerful sporting styling cues such as the enhanced front bumper, bonnet louvres and aluminium-finish grilles remain, while exclusive Celestial Black only exterior paint, 20in polished Cremona five-spoke alloy wheels and polished aluminium power vents incorporating the indicator side repeater and Jaguar signature ingot' add to the overall presence.

Inside a unique, Engine-Spun aluminium veneer is standard along with new alloy and leather gearshift selector, soft-grab door handles, contrasting stitching throughout the cabin, leather-edged mats with a Jaguar logo and distinctive Portfolio treadplates on the doorsills.

The interior also features a soft grain leather Luxury Sport Interior Theme' with seats in either warm charcoal (with ivory contrast stitching) or ivory (with charcoal contrast stitching).

The XKR Portfolio marks another first for the brand: the first production example of its new partnership with audio entertainment specialists Bowers & Wilkins, who also collaborated on the C-XF concept car.

Taking Jaguar's 525W Premium Audio system with Dolby Pro Logic II surround sound as a starting point, Bowers & Wilkins have crafted a signature speaker system specifically for the XKR's cabin.

High-output, low-distortion Kevlar mid-range speakers and aluminium-dome tweeters deliver mid-range and extended high-frequency responses.

To go with the XKR Portfolio's cosmetic enhancements, Jaguar's Special Vehicles team has also worked alongside leading brake manufacturer Alcon to create the largest, most powerful brakes a production Jaguar has ever carried.

The 400mm front brake discs, an increase of 45mm over the standard XKR, are retarded by powerful six-piston callipers, while at the rear four-piston callipers operate on 350mm discs.

Innovative race-developed crescent-shaped grooves cut into the surface of the discs to prevent a build-up of deposits on the brake pads and improve braking performance under extreme use.

Power comes from a 420bhp, 4.2-litre supercharged petrol engine capable of hitting an electronically controlled top speed of 155mph and accelerating to 60mph in just 4.9 seconds.

It operates using a six-speed Jaguar sequential shift transmission with paddleshift.

Jaguar is making just 500 examples of the XKR Portfolio with 60 allocated to the UK.

Although a final price has yet to be confirmed, it is expected to be about £5,000 above the standard XKR - the Portfolio is available to order from the end of March with deliveries expected later in the summer.