Long-awaited diesels give Subaru 4×4 and small hatchback an economy boost.

Subaru is soon to launch diesel-engined versions of its Forester off-roader and Impreza all-wheel-drive small hatchback.

The world’s first horizontally-opposed 2.0 diesel engine for a passenger car has won praise for its refinement, smoothness, sharp throttle-response and fuel economy. It first appeared in the Legacy and Outback earlier this year.

The Forester and Impreza Boxer Diesels feature new six-speed manual gearboxes while the engine benefits from a new closed-type diesel particulate filter. No other SUV can better the 44.8 mpg Combined and 167 g/km of the Forester 2.0D X.The Forester 2.0D produces 146bhp while the Impreza has 149bhp.

The engine is compact, light weight and has a low centre of gravity, which benefits handling and makes best use of the standard all-wheel drive system.

The new Forester Boxer Diesel gs on sale in the UK this month and the Impreza in January 2009.