Subaru's much-admired 2.5 litre turbocharged boxer' engine has won the 2006 International Engine Of The Year Award'.

Fitted to both the Forester 2.5 XT and Impreza 2.5 WRX and WRX STI, the engine was voted the best in the 2.0- to 2.5-litre class.

The award ceremony took placeat the Engine Expo in Stuttgart, Germany.

A panel of 61 renowned motoring and technical journalists from 29 countries served as judges in the competition organised by UKIP Media and Events Automotive Magazines. This is Britain's largest group of auto-technology magazines which includes Engine Technology International. The judges evaluated the vehicle's performance, drivability, fuel economy and refinement. Enlarged from 2.0-litre to 2.5-litre for the 2006 model year, the internationally-acclaimed Subaru engine has strong pulling power at low speed ranges and, thanks to a number of design changes, enhanced power higher up the engine's rev range.