Oil-burning Subarus a step closer

It's been 25 years in the making, but creating the world's first boxer diesel engine is no easy job!

Auto Express Car Reviews

Legacy will be first model to benefit from new flat-four diesel

19th February 2007

Last week, Auto Express revealed details of how Subaru's next Impreza will get an oil-burner in 2009, but now the Japanese firm has confirmed that its first 'boxer' diesel will arrive much sooner than that. Following its unveil at the Geneva Motor Show in March, the new powerplant will be launched in the UK early next year in the Legacy.

Technical details are still under wraps, but the unit, which has been developed in conjunction with parent firm Toyota, is expected to be a 2.2-litre four-cylinder unit delivering around 150bhp. A six-cylinder version is also in the pipeline. What makes Subaru's diesel unique is its layout, as the firm has stuck with its traditional horizontally-opposed cylinder layout. This has made diesel development difficult, because of vibration and refinement issues.

But Subaru has persevered with the engineering challenge posed by the boxer, because of the firm's belief in the advantages offered by its compact dimensions and low centre of gravity. Subaru claims its new diesel delivers superior performance compared to conventional rivals.

Combining the strong torque at low revs normally associated with diesel motors and a boxer engine's throttle response at high revs, the new oil-burner promises to offer a sporty power delivery.