The all-new 2-litre diesel unit returns 49.6mpg on the combined cycle while offering up 150bhp and a massive 258lb/ft of pulling power

Subaru has unveiled its first diesel engine – ever.

The Japanese marque has rolled out its first production diesel engine in the Subaru Legacy and Subaru Outback.

And the new 2-litre unit is also the world’s first ever ‘boxer’ style diesel engine, following in the footsteps of Subaru’s petrol engines.

The ‘boxer’ style setup – which means the pistons move from side to side as opposed to up and down – allows the engine to be fitted lower down, giving the diesel Subaru Legacy and Outback a lower centre of gravity.

And this gives the estate variants better roadholding and handling.

The all-new 2-litre diesel unit returns 49.6mpg on the combined cycle while offering up 150bhp and a massive 258lb/ft of pulling power.

Coupled to Subaru’s famous four-wheel-drive system, the 0-60mph sprint takes just 8.5 seconds.

Subaru is keen to keep refinement levels high in its very first diesel engine, and the moving sound levels of 70.5 decibels puts it lower than the Rolls Royce Phantom (72 decibels).

And Subaru has fitted a number of features which will only appear on the diesel models of the Legacy and Outback, including extra-sound proofing, electric-power steering, a revised suspension setup and uprated front brakes.

Inside, the diesel Subaru Legacy and Outback models gets aluminium strips, soft-touch plastics and a leather-covered steering wheel.

Lawrence Good of Subaru said: “The significance of this outstanding new boxer diesel engine cannot be underestimated.

“With a UK diesel market share now running at 40 per cent this is the answer to many loyal and potential customers’ future motoring needs.”

Prices for the new diesel Subaru Legacy Sports Tourer start at £19,995, and £21,495 for the diesel Outback model.