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Jaguar XJ Design Development

07 April 2003 | by Nick Hull

Many designers regard the original 1968 Jaguar XJ6 as one of the classic sedan shapes of the last forty years, so it’s maybe not surprising that many of the styling cues on this latest XJ redesign appear to echo those of the original car. However, this was not part of the original concept and, according to the design team, only emerged slowly as the project matured.

The story begins in 1997 at the initial project concept phase when the first sketches were produced and with the package still not fully established. The planning concept for the new X350 model demanded that the package, particularly interior space, had to grow considerably over the previous X300 model. That car, developed from the XJ40 conceived in the early 1980’s, was increasingly outclassed in many rational areas compared to key F-Segment competitors such as Mercedes S-Class, BMW 7-Series and Lexus LS430 and the new car was targeted to be fully competitive in this regard.

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First Photoshop design images by Tom Owen, Summer ‘97. Red marks indicate initial proposed cabin package

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2nd proposal, with shorter nose, longer tail

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As the hard points of the package became fixed, the design team were concerned about how they could accommodate the big increases in cabin and greenhouse dimensions and yet maintain the classic proportions, lightness and elegance which have become hallmarks of the XJ series. They therefore resorted to an early use of digital media to speed up the debate.

Principal Designer Tom Owen decided to demonstrate the implications of the proposed proportions using quick side view Photoshop renderings. This proved useful to move the discussions with product planning and packaging engineers ahead to a revised layout from which a scale tape drawing and three 3/8 scale models were produced in Autumn 1997.

One proposal, Theme W, was seen as having the most ‘stretch’ in terms of design and it was decided to press ahead with a 1:1 clay model based on this proposal for further form development.

At the same time, all the scale model proposals were photographed and retouched to provide four theme images for customer focus group discussions in Japan, UK and California.

Many respondents commented on the need to maintain the much-loved Jaguar core values and the distinctive silhouette of the classic XJ. From this exercise, one model - Theme T 'Evolutionary' – emerged as the leading contender.

By end of January 1998, the Theme W clay was ready for evaluation but the translation to a full size model was felt to be too generic – mainstream American even – with its arched roof profile, flowing DLO and high, falling tail. The clay model was therefore rapidly remilled around the Evolutionary Theme T to reflect the findings of the focus groups and reviewed again just 4 weeks later in February 1998.

The revised milled clay model had an immediate positive reaction when viewed by senior Jaguar executives. The stronger, more formal, front face and lower tail was felt to be much closer to 'Jaguar Heartland'. Although this design didn’t meet the strict aerodynamic or trunk space targets for X350 project, it was decided to accept it as the image model for the final design.

Over the next twelve months the design was constantly reworked and optimised to be fully feasible, particularly regarding the new aluminium body pressing technology. The body construction of the new XJ is a riveted and bonded aluminium monocoque - a totally different method from Audi and Honda’s extruded space frame concepts. This had several knock-on effects.

Firstly, the hood sculpting, especially around the headlamps, required careful modelling to ensure full feasibility. Secondly, the radii in the shutgaps from fender to bumpers required more investment to achieve a laser-tight condition. Finally, the rear fender/door shut pressing, with 6-light window and characteristic ‘haunch’, proved impossible to strike as a high-quality finished aluminium pressing.

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Final console design showing the addition of fine chrome detailing and the integration of the electric park brake behind the J-gate selector.

This area was heavily revised, with the C-pillar rake becoming more upright and a reversion to a simpler 4-light DLO.

Ironically, it is this area of the production X350 which most reminds one of the original XJ Series 1 in the satisfying way that the haunch, rear door and backlight nestle together. Another key device added at this refinement stage was the rising swage line running through the lower doors which helps considerably in slimming the bodyside, aided by the strong tuck-under of the simple sill section

“X350 is a much taller car and it’s hard to appreciate the difference until one views them together. Indeed we often insisted on viewings with the older car alongside just to reinforce the large differences in scale” comments Tom Owen.

Wheelbase on the final car is now a class-leading 3034mm and overall height is increased by 125mm over the old model, providing spacious rear passenger room and generous front seat legroom.

The interior design, led by Giles Taylor, takes design cues from the S-Type and XK8 and develops them for the new X350 project. Key themes include the ‘Spitfire Wing’ symmetrical IP, hooped centre console and large door veneer inserts. The first clay model, from May 1998, established the symmetrical high cowl theme which continued through to final production.

A second variation focussed on a non-symmetrical lip over the instrument binnacle and different graphics for the wood, vents and console connection but was finally dropped by February 1999.

The warm, cosseting ambience is given a contemporary edge with a sensual piano black finish to switchgear and J-Gate shifter, plus touchscreen navigation with voice control and an electronic park brake.

In addition to an electrically adjusted steering wheel, the new XJ also features a powered brake and accelerator pedal assembly for additional fine-tuning of the driving position.

Current Director of Design, Ian Callum, took over after the sudden death of Geoff Lawson in August 1999, mid-way through X350 project. He sums up the car by saying "The new XJ is a luxury car with a true sense of gravitas. The proportions, stance and obvious dynamic quality clearly display that all-important Jaguar DNA and give it real presence on the road".

Car Design News would like to thank Tom Owen, Principal Designer, and Jaguar Public Affairs for their help in the preparation of this article.

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Early sketch by exterior designer Sandy Boyes

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Renderings of the final design

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Four scale model images used for customer focus groups, late ’97. K-design thought to be the most advanced, T thought to be the most evolutionary, W silhouette thought to be too generic, with high tail, Y sloping front end not “Jaguar”. Overall design was felt to be too revolutionary for UK customers

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Scale tape drawing with supporting theme images

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3/8 scale clay model A (later Theme W), with low front end, December ’97. Alternative ‘rolled’ front end was later preferred

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Jan ’98 full-size clay model of Theme W. The sloping front grille was seen as “typically British” but not instantly recognisable as a Jaguar

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Feb ’98 full-size clay model of Theme T, 'Evolutionary' which became the image model for the final design. Note softly-waisted body section and 6-light cabin

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Final clay design approval model, May ’99. Note the change to a simplified body section with pronounced rising line running through the lower doors, with characteristic XJ6 large outer headlamps and egg-crate grille

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Design approval model, May ’99. The design was now modified to a 4-light cabin with slimmer, more upright rear C-pillar and typical XJ6 taillamps

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Key interior image sketches emphasising a sensual and inviting ambience

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Early clay model development showing the hi-cowl theme and slim 'Spitfire Wing' veneer graphic, May ‘98

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Feb ’99. Final chosen theme, with centrestack hoop console connecting directly with the facia veneer

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Alternative Theme D proposal showing an asymmetric upper IP with the centre vent completing the graphic

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Final interior buck for design approval, April 2000

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X350 design team, 1999