The long-wheelbase 2005 XJ weighs 53 pounds more than than normal XJ yet is 5 inches longer.

Here is another article about Jaguar and aluminum

(It mentions a 2010 XK but this article was written before Jaguar announced the X150, the code name for the next XK).

http://wardsauto.com/ar/auto_jag_ponders_aluminum/index.htm

-- Edited by Lewis at 05:27, 2005-04-27

Here is an article from http://www.sts.sae.org/servicetech/sep-2003/xj-something.pdf

(the link no longer works so I'll post it here)

September 2003
XJ is something different: The new Jaguar sedan, with its all-aluminum monocoque construction, will provide some challenges for body shops and technicians alike.

by Paul Weissler | Service Tech

Jaguar says its 2004 XJ is the world’s first mass-produced, all-aluminum “monocoque.” But maybe you are thinking, “Hey, that’s just for the body shops to worry about.” Well, there are things for technicians to realize too. Like any monocoque, including an airplane, the body panels form an important part of its strength. That means “creative time-saving” is not a possibility, such as cutting some little access panel in an out-of-sight location, then covering up the opening with some sheet aluminum and pop rivets.

Interestingly, the XJ is not welded (well, it has a few, primarily for specific issues). It is built with 3180 self-piercing, high-strength rivets and 394 ft (120 m) of structural adhesive (a one-step epoxy). Because the rivets alone would provide a much stronger assembly than the 5000 welds typical for a car of this size, the overall result is “belt and suspenders.” However, the adhesive really silences body vibrations, and that is reason enough for its use.

An old gag refers to a vehicle “held together by its paint job,” and there is a kernel of truth in that with the XJ. The aluminum body panels use a special alloy that is “bake-hardened” in the paint oven—to 165°C (330°F)—substantially increasing their strength (particularly resistance to dings). And the epoxy cures in that same oven.

The new model is 60% torsionally stiffer than the previous XJ, but thanks to all the aluminum, the car is over 200 lb (90 kg) lighter, despite greater size. The use of magnesium—which is as strong as aluminum but 30% lighter still—for the XJ’s seat frames and cross-car beam that supports the instrument panel and steering column also contribute to mass savings.

If a glued/riveted panel has to be replaced in a body shop, Jaguar has approved a two-step epoxy that cures at ambient temperatures. Happily, the front fenders and front bumper structure are bolted on for easier repair. The front-end module is said to be able to withstand a 10-mph (16-km/h) impact without structural damage being inflicted thanks to its impact-absorbing properties between the front-end module and body shell.

Made from injection-molded plastic, the bumpers of the new XJ are designed to withstand a 5-mph (8-km/h) impact without structural damage. “Lift-off” door hinges make removal easy if collision repair is needed, reducing time and cost.

As for those few welds, the roof is welded on because it helps produce a cosmetically superior appearance at the four corners. And a few parts from outside suppliers include welds. More importantly, the 26 body electrical grounds are supplied by welded-on studs and nuts because the glue is not conductive. If one of these grounding fasteners ever breaks off or suffers irreparable damage to threads, a replacement can be welded on unless an aftermarket repair kit becomes available.

-- Edited by Lewis at 05:34, 2005-04-28

Jaguar Chooses Novelis as Aluminum Supplier for New XK

October 14, 2005 - Novelis Inc. announced today that it has been selected by Jaguar Cars Limited as the sole supplier of aluminum sheet for the new Jaguar XK sports car to be launched in early 2006.

The all-new XK features an advanced aluminum body structure constructed with the aid of technology from Novelis.

Each Jaguar XK will contain some 330 lbs (150 kg) of Novelis aluminum sheet, helping to deliver a vehicle with excellent stiffness and rigidity while minimizing weight. The new XK provides significant improvements in performance, dynamics, safety and fuel economy. The power-to-weight ratio of the new car is superior to its predecessor despite the addition of advanced electronics and other luxury features.

The XK program continues the close cooperation between Novelis and Jaguar, which began with development of the aluminum-bodied Jaguar XJ sedan, launched in 2002.

"We were delighted when Jaguar announced that aluminum would be part of its lightweight materials technology strategy, which will be a hallmark of Jaguar's performance cars in the future," said Brian Sturgell, president and CEO of Novelis. "We are proud to support the lightweighting strategy and to supply all of the aluminum sheet for both the XJ and now the XK."

Novelis automotive specialists worked alongside Jaguar engineers and designers to provide expertise in materials technology from initial design of the new XK, through prototype development, right up to vehicle manufacturing. High-strength aluminum sheet from Novelis will be used for the outer skin of the new car as well as complex structural parts. The company's Aluminum Vehicle Technology (AVT) will also be a feature of the production of the new XK, as it is for the XJ. The major innovation of the system is the adhesive bonding of sheet panels in combination with self-piercing rivets.

Novelis is the world's leading supplier of aluminum automotive sheet. Material for Jaguar is produced through the company's European rolling system. Hot-rolled coils from the Norf rolling complex at Neuss, Germany, and the Novelis facility in Sierre, Switzerland, are further processed at the company's specially-equipped operations in Sierre and Nachterstedt, Germany. As part of Novelis' double-sourcing strategy, the material can be processed at either of these plants, given a special heat and surface treatment and cut to the customer's required shape - be it the traditional rectangular and curved sheet or more complex laser-cut shapes. The Nachterstedt plant features a euro 15 million (US$18 million) laser blanking centre and Novelis intends to expand the Sierre plant with a similar centre by mid 2006.

Novelis also provides closed-loop recycling for Jaguar and will take the aluminum off-cuts from XK production back to its Warrington (UK) recycling centre, as it does currently for the XJ. As part of a shared drive towards sustainability by Jaguar and Novelis, the metal is recycled directly into new automotive sheet, thus saving resources and up to 95% of energy that would be required to produce primary aluminum.

Novelis, which was spun-off by Alcan on January 6, 2005, is the global leader in aluminum rolled products and aluminum can recycling. The Company has 36 operating facilities in 11 countries and more than 13,000 dedicated employees. Novelis has the unparalleled capability to provide its customers with a regional supply of high-end rolled aluminum products throughout Asia, Europe, North America, and South America. Through its advanced production capabilities, the Company supplies aluminum sheet and foil to the automotive and transportation, beverage and food packaging, construction and industrial, and printing markets. For more information on Novelis, visit www.novelis.com.