Jaguar XJS H.E.

Revised XJS highlights Jaguar’s quest for quality and economy

The 5.3-litre Jaguar V12 engine has earned an enviable reputation over the past decade as a silky smooth power unit propelling the most refined machines in the Jaguar/Daimler range. The brainchild of William Heynes, Claude Bailey, Walter Hassan and Harry Mundy, the V12, then fitted with four carburetters, first appeared in the E-type Series 3 in 1971. Since that time it has been used to power the Daimler Double Six/Jaguar XJ saloon range, the XJC coupe and the superb XJS coupe. Now, in a major quest to push the V12’s fuel economy into what’s described by Jaguar Daimler as the “psychologically important 20 m.p.g. bracket”, heavily revised H.E. (standing for High Efficiency) versions of the engine are being fitted into the entire range, offering a fuel consumption on excess of 20 m.p.g. for out-of-town motoring. We have thus recently been trying the Jaguar XJS H.E. which, with an improved claimed top speed of 155 m.p.h., is the world’s fastest automatic transmission production car. More importantly, its Department of Energy fuel consumption figures are stated as 27.1 m.p.g. at 56 m.p.h., 22.5 m.p.g. at 75 m.p.h. and 15.6 m.p.g. for the urban cycle.

The introduction of this revised V12 engine coincides with a major quality and reliability campaign instigated by Jaguar Cars Ltd. in an effort to clean up their image when it comes to reliability and customer satisfaction. Existing in a highly exclusive bracket of the luxury car industry, Jaguar realise only too well that a customer lost is doubly difficult to get back than in the lower-price car sales sector. Once a Jaguar customer has been lost to Mercedes-Benz, BMW or Porsche, there has to be a pretty persuasive reason for his returning to the XJS/XJ12 fold. This quality and reliability campaign is designed to provide that persuasive reason in the simplest form possible: by building better quality, better finished, more reliable motor cars.

Jaguar claim that their programme is unparalleled in the British motor industry. It began after John Egan took over as Chairman and Chief Executive in April 1980 and involves every Jaguar employee from the shop floor to Chairman’s office. Egan puts the problem squarely: “When I joined Jaguar it soon became clear to me that we had to put every possible effort into matching our quality up to the acknowledged levels of Jaguar excellence in design and refinement. A short term approach was not the answer. We needed an in-depth committment to quality and reliability in all our plans and in those of our suppliers. An absolute and pervasive obsession with the ideal of ‘right first time’ had to become a way of life for all of us.”

To start with, the “quality circle” concept, as made famous by Japanese industry, was introduced. There are now nearly 50 such “trouble-shooting” groups across the three plants at Brown’s Lane, Radford and Castle Bromwich. Shop stewards, supervisors, inspectors and hourly paid production workers are all represented in these circles which meet regularly to pinpoint and rapidly develop solutions to minor problems in the area concerned. Next in the quality control hierachy comes the Quality Actions Groups whose responsibilities vary according to the seriousness of the problem. But by far the most hard-hitting decision came when Jaguar told ”problem” suppliers that they must improve their performance or they would lose Jaguar business. The management decision to take this action was founded on the fact that, in early 1980, Jaguar’s 1,700 outside suppliers were responsible for 60 per cent of the company’s quality and reliability problems. Those who failed to respond to this initiative soon found that they lost Jaguar business and any suppliers whose components gave a problem incidence of more than 1.5 per cent found themselves being pursued by Jaguar for full warranty cost of labour and materials. The response has been excellent in an overwhelming number of cases, with rejection rates on certain items cut from over 50 per cent to a norm of less than one per cent.

Add to all these new procedures Jaguar’s insistence on more precise specifications of material and functional requirements of the components, together with quality and reliability procedures intent on aiding the supplier to maintain the design quality of those components and a painstaking level of pre-delivery checks, and you have Jaguar’s recipe for future success. How does it all appear in reality?

Well, we at Motor Sport have always been impressed with the XJS coupe. Its appearance has always been a matter for personal taste (the writer, by the way, has never been able to understand those whose accuse it of looking rather strange from the rear) but its level of equipment and overall air of refinement have never been called to question. Up to now, the main criticisms levelled at the XJS have been ones of reliability and quality control – plus heavy fuel consumption. We have already explained how Jaguar propose to defeat the former criticisms. The astonishing improvements in fuel economy stem from the adoption by Jaguar engineers of the “Fireball” combustion chamber principles invented by Swiss engineer Michael May. Jaguar engineers have spent five years perfecting the May principles to suit the demands of a production engine application.

Best described as a “split level” arrangement within the combustion chambers, the May design has its inlet valve set into a shallow collecting zone and the exhaust valve set higher up within the “bath tub” type combustion chamber which also houses the sparking plug. A swirl-inducing ramped channel connects the two areas and, as the piston rises during the compression stroke, the mixture charge is pushed out of the inlet valve pocket and swirls rapidly round into the main chamber. This aids the rapid and complete burning of very lean fuel/air mixtures and means that high compression ratios can be employed with 4-star, 97 octane fuel.

On first acquaintance with our road test XJS we were struck by the sheer depth and lustrous quality of the paint finish. Inside, the level of trim is lavish, superbly assembled and tastefully styled. Top quality elm burr veneer has been added to the opulent leather trim in response to demands from the United States market for more overt signs of luxury. On the outside the car’s distinguished lines have been enhanced by the use of Series 3 saloon style, rubber faced bumpers, attractive new five spoke, dome design alloy road wheels and a tapering twin coachline running the entire length of the body.

Firing up the fuel-injected V12 is a matter for continuing pleasure. Superlatives have been used time and time again to describe its character and mode of operation, but one is always pleasantly surprised. Really, it feels like some sort of electric turbine! To describe the characteristics of the XJS coupe yet again in detail would be to laboriously retrace steps taken on many occasions over the past few years within the pages of Motor Sport. But the agility of this quite substantial machine is something one never quite gets used to. Critics still say that the XJS rolls a little too much for really determined press-on, cross-country motoring, but Adwest power­-assisted rack and pinion steering induces such confidence and assurance that we found it is still possible to place this huge car to within a matter of inches on narrow roads with no worries whatsoever. From a sheer personal “feel” point of view, I would like a slightly thicker steering wheel rim, and I still find it a little difficult to believe that such light steering can exact such a positive response. But the XJS’s sure-footed progress is further aided in its H.E. specification by the addition of an extra half-inch of wheel rim width carrying Dunlop’s advanced D7 70-series SP Sport rubber which has been developed in Britain specifically to suit Jaguar and Rolls-Royce requirements.

These new tyres obviously make their contribution to even higher levels of stability at speed and the XJS H.E. has outstanding wet weather manners, unflustered by heavy braking on fast corners. The GM400 automatic transmission is retained (there is no manual option) and a limited slip differential is provided as standard equipment. The engine’s improved torque characteristics have allowed the final drive gearing to be raised from 3.07:1 to 2.88:1 which provides 27 m.p.h. per 1,000 r.p.m. in top gear, making for slightly more relaxed high speed cruising and a top speed of around 155 m.p.h. for those who thrive on regular trips along German autobahns!

Obviously in a car of this quality, electrically operated windows are provided; there is a timer linked to the heated rear window, automatically switching it off after 15 minutes, and another timer activates a delay on the interior courtesy lights of some 15 sec. In the boot, the vertically mounted spare wheel and battery box are covered by fully-tailored carpeting, there is a fully equipped attache case-styled tool kit and cruise control is offered as an extra-cost option. As the last word in refinement for the XJS occupants the Philips 990 micro-computer controlled stereo radio and cassette player is fitted as standard equipment, offering up to 60 different transmitter frequencies for “storage” in its electronic memory system.

As an indication of Jaguar’s faith in their product, the XJS H.E. is priced at £18,950.37, representing a reduction of £723 over the previous such model. That sort of faith, allied to the effort obviously being put into the quality control processes at their factories, deserves to be richly rewarded. – A.H.