London  - Jaguar has given the XF luxury saloon a more powerful diesel engine which is said to save fuel at the same time.

The 3 litre, six-cylinder turbo diesel unit in the XF Diesel S replaces the current 2.7-litre unit, boosting performance by 33 per cent. Despite the power gain, the bigger engine
(275 horsepower) is said to be 12 per cent more fuel-efficient and it cuts carbon dioxide emissions by 10 per cent to 179g/km. The car will feature at the Detroit car show from January 17-25, 2009.

The engine uses an innovative parallel sequential turbocharger system which Jaguar says improves efficiency and reduces fuel consumption. For most everyday driving, including motorway cruising, a primary turbocharger does all the work. When the engine revolutions climb above 2,800 rpm, the secondary turbo comes on stream, boosting engine output.

The new XF Diesel S also gets some trim and specification changes to set it apart from other models in the range. These include new 20 inch alloy wheels and a discreet boot lid spoiler. A new Portfolio version will be added to the XF line-up in 2009, with aluminium wing vents and bespoke leather interiors. (dpa)