Subaru develops horizontally opposed Turbo Diesel engine

Subaru Europe President Hiroyuki Ikeda dropped an unexpected announcement in his Paris motor show speech when he mentioned that the company was working on a SubaruBoxer Turbo Diesel and that development is nearly complete. The horizontally opposed engine layout made famous by Volkswagen has long been favoured by Subaru and has been the mainstay of its fleet for more than three decades with its latest effort winning first place in the 2.5-liter class of the International Engine of the Year Awards. Though it’s logical that the company would develop the world’s first horizontally opposed diesel engine, there are many technical difficulties to overcome, so it was by no means regarded as a given. Anyway, we have the drawings in high res and we suspect it’ll be a beauty.

The superb rotational balance of the horizontally-opposed engine allows low vibration because the pistons counteract each other to cancel it out. Moreover, with its firmly supported crankshaft, the crankcase construction is strong enough to resist huge combustion pressure. The horizontally-opposed engine’s character is proving an excellent match for a diesel engine.

Ikeda said, “the adoption of a thin journal for the crankshaft and turbo charger placed under the cylinder block enhances all the advantages of the Boxer Engine, which are a low center of gravity, lowvibration, high rigidity and compactness.”

Ikeda said he anticipated unveiling the Subaru Boxer Turbo Diesel engine next year at Geneva Motor Show.