Subaru goes diesel

SUBARU has almost completed work on the world’s first horizontally-opposed four-cylinder diesel engine, the Subaru boxer turbo-diesel.

Announced at last week’s Paris motor show by Subaru Europe president Hiroyuki Ikeda, the engine has been developed by Subaru parent Fuji Heavy Industries in Japan and will initially be aimed at the European market.

Subaru Australia has also expressed interest in the engine, which is believed to have a capacity of 2.5 litres.

A production timetable has not been set, however, GoAuto understands the engine could be in service by the end of next year, and should appear first in Forester. It will be officially revealed at the Geneva motor show in March.

Subaru says its horizontally-opposed "boxer" cylinder design lends itself well to turbo-diesel technology, because its compact design allows a low centre of gravity and because its inherent rotational balance reduces vibration.

The design, pictured at left, reveals a turbo that's below the crankshaft line, instead of near the firewall as on most turbo (petrol) Subarus, to retain the boxer's low centre of gravity, and a valve timing chain. Currently only seen on Subaru's H6 engines, it will be the first H4 engine with a timing chain, rather than belt.