As well as recent changes to the styling for a more assertive and sporting appearance, there have been significant improvements to the interior, an all-new front seat design for improved comfort and an increase in rear leg- and foot-room.

The revised line-up of the all-aluminium saloon comprises three models: Executive and Sovereign specification with a 2.7-litre, V6, twin-turbocharged diesel engine developing 204bhp, and the 4.2-litre, supercharged V8 petrol developing 400bhp in Super V8 trim.

The XJ 2.7 diesel was named Britain's Greenest Luxury Car in the Environmental Transport Association's 2008 Car Buyers Guide, the second year running it has won the award.

It is capable of 35.7mpg on the official EU Combined fuel consumption cycle (26.5mpg Urban), while CO2 emissions are down to 209g/km from 214g/km. All models have a six-speed automatic transmission.

The Executive 2.7 diesel costs £44,599 and now includes satellite navigation as standard as well as front and rear parking aids, Bi-xenon headlamps with headlamp washers, bright mesh lower grille and side vents and Jaguar tread plates.

Sovereign specification, costing from £50,472, includes 20in alloy wheels, soft grain leather heated and cooled seats with embossed front headrests and a leatherette instrument panel and grab handles, plus Jaguar tread plates and a lambs wool rug set front and rear.

It also has metallic paint, electric, folding mirrors, heated rear seats and a premium sound system with six-CD changer and Jaguar Voice.