Jaguar has, as has been traditional with the model line, has extended the XJ saloon range with a new, long wheelbase version, on sale from autumn.

The new derivative made its debut at the New York motor show.

“The long wheelbase version will be a key addition to the XJ range, particularly in the United States where we expect it to account for the majority of sales,” a spokesman told

The ‘stretched cat’ of course provides greater room for rear seat passengers but also offers a choice of seating configurations, new trim and specification options and a variety of communications and multi-media equipment packages, yet is claimed to weigh just 24kg (53lb) more than the standard wheelbase model while posting fuel economy, emissions and performance figures “equivalent” to the standard wheelbase models.

The wheelbase and overall length of the new long wheelbase car have increased by 125mm (about 5 inches) and the rear roofline is raised 7mm (0.28 inches).

The additional body length is behind the B-pillars, and rear doors are longer, though less obviously so than on previous models.

Jaguar claims the XJ8 LWB is comparable with the best-in-class for rear accommodation, offering 999mm (over 39 inches) of legroom and fully class-competitive headroom.

There is a choice of four rear seat configurations, including fixed or power-adjustable bench layouts and individual powered and heated rear seats separated by a centre console with additional storage space.

Burr walnut-finished ‘business trays’ big enough to hold a notebook computer fold down from the front seat-backs and options include 6.5-inch display screens in the head restraints of the front seats, along with with rear seat multi-media options like iPod, MP3 player and DVD connectivity. Communication possibilities include telephone conferencing for front and rear passengers and those in the back can specify voice activation for the four-zone climate-control system, with individual seat settings.

Engine availability varies with the market but disdtributors can choose from naturally aspirated 3.5 and 4.2 litre V8s and the 400bhp supercharged 4.2 litre V8, all matched to Jaguar’s advanced ZF six-speed automatic transmission.

But the UK-based, Ford-owned carmaker still lags behind German rivals that offer superbly refined and fuel-efficient six-cylinder and V8 turbodiesels aimed at fuel cost-conscious European executives.

The aluminium monocoque body shell is claimed to have retained its exceptional stiffness and light weight, while spring and damper settings and suspension mounts and bushings have been revised to give the LWB version the same ride, handling and steering feel qualities as the standard wheelbase model while revised suspension mountings are said to have reduce transmitted noise levels and improved overall refinement.