Featuring the 5.3 ltr V12 motor that had been introduced in the series 3 E-Type it became the ultimate ‘Businessman’s Express’. The XJ12 had some minor styling differences to the XJ6, notably the grille featured vertical slats and the use of V12 badges inside and out. The XJ12L followed soon and the car was promoted as the ‘fastest four door saloon in the world’ and ‘capable of 140 m.p.h.’ again demand outstripped supply and the press were suitably amazed and impressed. The ‘Double Six’ was the Daimler version of the XJ12.

In 1973 Jaguar had to bow to the U.S. safety regulations and re-design the XJ. This resulted in what became known as the ‘Series 2’ cars. The new XJ6, XJ12 and Daimler cars were all built on the long wheelbase platform after a small number of cars built on the original shorter wheel base. The exterior of the series 2 had the smaller grille above and wider separate grille below the re-positioned bumper bar. The interior of the car was also changed with instruments, switch gear and controls in more ergonomic positions, also the heating and aircon was updated to be more effective. Series 2 production was problematic at times due to industrial unrest and ended in 1979. An interesting sidelight was the production of the XJ Coupe which has become the most desirable and valuable of the Series 2 cars.

In 1979 the XJ was given a third life as the Series 3 model. An exterior re-design by Pininfarina gave the Jaguar more window space, better streamlining and a revised grille similar to the Series 1 V12. Also; flush door handles and a revised roof line helped to give a more modern look. Mechanically the biggest change was fuel injection of the venerable XK 4.2 ltr engine and the 5.3 ltr V12. It was also offered in 3.4 ltr form as an economy model. The interior was also upgraded with more woodgrain and from 1982 the first trip computers fitted to Jaguar cars. The 1983 Series 3 also saw the transfer of the name ‘Sovereign’ from Daimler models to the Jaguar model. There were Daimler ‘Vanden Plas’ and ‘Double Six’ models to be had as well. Production of the Series 3 continued until 1992. This model is widely seen as the most practical of the ‘classic’ XJ models to own.

From 1986 the XJ40 model was in production. This model introduced a whole new body design with a very squared off look. It also introduced a new family of engines as the legendary XK unit was replaced with the AJ6 engine in 3.6 ltr and later in 4.0 ltr capacity. The XJ40 was not designed with the V12 5.3 unit, however public demand meant that a small number of cars were built late in the run with this engine.

In 1994 the X-300 version of the XJ was introduced. Jaguar was now owned by Ford and this company tightened quality control and consistency of manufacturing. The body design returned to a more traditional rounded shape and the single rectangular XJ40 headlights were changed back to double round units. The AJ6 engine was upgraded to the AJ16 unit and the V12 now rated at 6.0 ltr capacity was available in limited numbers. Most excitingly the X-300 introduced the supercharged XJR variant which has become such a mainstay in the XJ line-up ever since.

In 1997 the X-308 was released. This incarnation of the XJ was the first to be powered by a V8 engine, the AJV8 in 4.0 ltr capacity. This earned the new name of XJ8 for the car. Very similar to the X-300 the new X-308 XJ8 did have subtle upgrades to body and interior. The XJR variant was also produced. Construction of this model ceased in 2003 when the X-350 appeared.

The X-350 was the swansong for the traditional shape of the XJ car first seen in 1968 when Sir William unveiled the Series 1. Larger and higher than the X-308 the new XJ sported either a 4.2 ltr or 3.5 ltr V8. However; there was also an XJ6 model using the 3.0 ltr V6 from the modern S-Type and the 2.7 ltr diesel. Body panels were made from aluminium and this lightweight construction translated to quicker performance. Both standard and long wheelbase versions were made. Interior luxury was taken to the next level in this car and the newest technology was available. An excellent car the X-350 was soon overshadowed by the revolutionary X-351.

The latest XJ was released in 2009, it mirrored the revolution in Jaguar styling begun with the medium size XF Saloon. With its coupe style roofline, cats eye headlights and prominent squared grille the new XJ is a complete departure from the past. The interior is very modern and includes LCD displays for all instruments and video system. Leather is still in abundance and the tradition of attractive wood veneers is still very evident along with more modern trim materials. Both standard and long wheelbase versions are made. Mechanically the new XJ began life with the 2.7 ltr and 3.0 ltr 6-cylinder motors of its X-350 predecessor. Also; a V8 5.0 ltr engine for the high-end variants is available in normal and supercharged versions. The latest XJ is a current model still in production and has carried the XJ name well and truly into the 21st century.