Innovation, Imagination, Intelligence

New XJ Skeleton - Structure

Aerospace-inspired aluminium construction sets the new XJ apart. In the way it performs, the way it rides, the way it handles. The way it uses less fuel and produces fewer emissions.

  • "We didn't decide to use aluminium because it was new or something different," explains Mark White, Jaguar's chief technical specialist for body engineering. "It's because aluminium delivers real and significant benefits for the drivers and passengers of the new XJ. Ultimately, an owner may not care whether the body is made of aluminium or steel. But what the Jaguar owner does care very much about is the way the car performs and handles - the way it rides. And that's where aluminium delivers.

    "White and his team have learned a lot about aluminium construction since the debut of the groundbreaking, previous-generation XJ in 2003, and with the all-aluminium XK in 2006. Developments in computer-aided design, the introduction of intelligent new technologies, plus the opening of Jaguar's own space-age Virtual Reality Centre, where designers can interact with a life-size model of their creation, have allowed advanced construction techniques to evolve at a pace previously unimagined.

    The team has been able to devise innovative ways of reducing the number of components that make up the body structure. For example, the new XJ has switched from using three aluminium components in its doors, to a single-piece design, which is lighter, stiffer and more durable. In addition, approximately 50 per cent of the new XJ's body structure is made using recycled aluminium, saving massive amounts of energy and dramatically reducing emissions.

    To save further weight from the structure other light metals such as magnesium have been used. One example is the front section, where a large, single-piece magnesium casting is used to save additional weight and deliver a high-quality build.

    The new XJ's body structure is a masterpiece of advanced, intelligent technology. A 'team' of 88 robots applies almost 2800 self-piercing rivets, and more than 90 metres of aerospace industry-sourced epoxy adhesive to bond the aluminium pressings, castings and extrusions together to create the very stiff and durable structure.

    The result is a body that is stiffer than most steel equivalents - providing the perfect platform for the XJ's suspension to deliver benchmark ride comfort and responsive handling. It also means a body that weighs over 150kg less than the average steel-based body in its class. Less weight means less mass to move, with the benefit of improved fuel economy and lower emissions.

  • Less weight helps the XJ's brilliant new line-up of engines deliver their levels of towering performance with benchmark fuel economy. These all-new 5.0 Litre AJ-V8 and 3.0 Litre AJ-V6D diesel Gen III powerplants are Jaguar's new racing hearts. They are the most technically advanced, most efficient engines that Jaguar has ever created.

    Three versions of the new, state-of-the-art AJ-V8 Gen III are on offer, each featuring intelligent new technologies, such as direct fuel injection, and an industry-first use of variable camshaft timing, where the camshafts are activated by engine torque (rather than oil pressure), saving energy and reducing fuel consumption.

    Headlining this new range is the supremely powerful 510PS (510hp) supercharged 5.0 Litre, which is reserved exclusively for the XJ's Supersport derivative. It provides this flagship XJ with effortless, slingshot rest-to-60mph sprinting in just 4.7 seconds (0-100kph in 4.9 seconds). There's also a potent 470PS (470hp) version, capable of delivering 0-60mph sprints in just 4.9 seconds (0-100kph in 5.2 seconds), and a naturally aspirated V8 that produces an impressive 385PS (385hp) and 0-60mph acceleration in 5.4 seconds (0-100kph in 5.7 seconds).

    Equally groundbreaking is the XJ's sensational new high-performance, high-efficiency 3.0 Litre AJ-V6D Gen III diesel. Compared to the previous, highly acclaimed 2.7 Litre diesel, this new engine boosts power by a remarkable 33 per cent to 275PS (275hp), while maximum torque soars by 38 per cent to a magical 600Nm (450 lb-ft). All this mechanical muscle translates into true sports car levels of performance: 0-60mph sprinting in just six seconds (0-100kph in 6.4 seconds), and an electronically limited top speed of 155mph (250kph). Yet this new diesel delivers its exhilarating performance without compromise. Both fuel consumption and CO2 emissions are class-leading.

    "What really sets this new diesel apart is its addictive low-speed throttle response – that instant reaction you need when you pull out of a junction, or want to overtake another car," says Malcolm Sandford, Jaguar Engine Group chief engineer.

    Much of this is down to the unique, twin sequential turbocharger system, the first of its kind to be fitted to a V-engine. The way the system works is that, for most day-to-day driving, the bigger, variable-geometry primary turbo does all the work. In the background is a smaller, fixed-geometry secondary turbo waiting to be called in. Accelerate hard and, as the tachometer needle on the XJ's new Virtual Instruments sweeps past the 2800rpm mark, the secondary turbocharger comes on-line within just 300 milliseconds. There's no turbo lag, or power step; the transition is smooth and seamless.

    Both diesel and petrol engines deliver their refined muscle through an enhanced version of Jaguar's fully-adaptive ZF six-speed, electronically controlled automatic transmission. It's the benchmark in this class. Gearshifts don't come any smoother, or faster.

    "The new XJ really moves the needle in the luxury saloon class," adds Malcolm.

  • FRESH, GREEN THINKING

    Imagine 12,000 aluminium drink cans stacked high. Melt them down, recycle them, and that's the amount of reclaimed, recycled aluminium that goes into the construction of the new XJ's aerospace-inspired body.

    "That's 50 per cent of the weight of new XJ's body structure, and a potential saving of 3.3 tonnes of CO2 for each new XJ compared to a car using 100 per cent non-recycled aluminium," says Martin Brown, manager of sustainability attributes at Jaguar.

    The XJ's lightweight aluminium body construction is at the very core of Jaguar's uncompromised focus on environmental responsibility. It's a focus centred on using new materials that drive weight from its cars. It's a focus on developing highly advanced engines that deliver remarkable efficiency and CO2 performance. And it's a focus on improving Jaguar's manufacturing processes to dramatically reduce energy use.

    Ten years ago, Jaguar laid down a strategy for building more efficient cars with the development of a lightweight aluminium body structure. Advanced aluminium construction - based on aerospace methods - delivering a body with great strength and rigidity, but with dramatically reduced weight compared with steel. The result was the remarkable new XJ saloon in 2003 and the all-new XK sports car three years ago.

    "It's an enlightened, intelligent approach, that focuses on every stage of the XJ's life cycle - from its design, throughout its assembly and the moment it takes to the road, right the way to the time it ends its life," explains Martin.

    Now, the all new XJ takes Jaguar's environmental responsibility to a new level with the introduction of a ‘second-generation' aluminium body structure. Painstaking research and analysis, along with thousands of hours of computing time, have enabled Jaguar's engineers to improve the design further, optimising the use of different grades and gauges of aluminium. The car also has high-strength aluminium in key areas - such as around the roof structure - and a wider use of ultra-lightweight magnesium to further shave weight from the front end of the car.

    The use of recycled aluminium for up to 50 per cent of the body structure has also seen major reductions in energy use. As Martin explains: "If it takes 100 per cent of energy to create new sheet aluminium, only five per cent is required to recycle waste into sheet metal again."

    That sustainability stretches to Jaguar's assembly plants, which have introduced measures to significantly reduce the energy used in building the new XJ. The new XJ takes less time to build than the previous model. Some of the body panels - such as the front and rear fenders - also need fewer stamping actions. And the energy consumption reductions achieved by using the bonding and riveting process, compared to welding steel, are significant. At Jaguar's Castle Bromwich assembly plant, there are no explosions of fiery molten metal as body panels are welded together. The XJ bodyshop provides a clean and quiet environment as rivets are pierced into the aluminium components that make up the body structure.

    Next to the XJ's aluminium body structure, the biggest environmental gains come from the new generation of Jaguar AJ-V8 Gen III petrol engines and the advanced AJ-V6D Gen III diesel. The new 3.0 Litre diesel engine already meets the forthcoming EU5 emissions regulations, ahead of their 2011 introduction date. All-new direct-injection helps the 5.0 Litre AJ-V8 Gen III petrol engines show dramatic enhancements in efficiency and meet stringent EU5 and North American ULEV2 emissions regulations. 

    And when the time eventually comes for an XJ's life cycle to end, Jaguar engineers have designed the car to be no less than 85 per cent recyclable. It's all part of Jaguar's uncompromised focus on making cars that are truly exhilarating to drive, as well as being environmentally responsible to own.

  • THE STORY OF ALUMINIUM

    - Because of the early difficulties in extracting it, 150 years ago aluminium was worth more than gold
    - Jaguar was one of the first car makers to use the metal, with its aluminium-bodied XK120 sports car in 1948
    - The 2003 XJ was the first volume-production car to use an all-aluminium monocoque chassis
    - This class-leading strength and rigidity was then used in the all-new XK sports car
    - There's no difference in quality between new and recycled aluminium
    - At the end of an XJ's life, almost 100 per cent of its aluminium is recyclable
    - The weight of an aluminium sphere with a diameter of 10cm would be 1.4kg - the weight of a plain mild steel sphere of the same size would be 4.1kg

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