Subaru fans rejoice. Fuji Heavy Industries Ltd. (parent company of Subaru) has pulled the wraps off of its new-generation four-cylinder boxer engines. OK, it's not that exciting, but if you're already a fan of Subaru's quirky engine configuration, the promise of more power and more efficiency for new models should at least get you grinning.
The boxer engine (or flat engine), for those unfamiliar, features a four-cylinder, horizontally opposed configuration with a pair of pistons punching out toward either side of a central crankshaft--like the fists of boxers. This third generation boxer engine incorporates new improvements in fuel efficiency, performance, and (hopefully) smoothness, while maintaining the configuration's trademark compact size and low center of gravity.
Fuji Heavy Industries will offer the new boxers in 2.0- and 2.5-liter displacements and claims an overall 10 percent improvement in fuel efficiency for the engines. The extra efficiency comes thanks to a combination of a more compact combustion chamber geometry and longer stroke, optimization of intake port configuration, and the use of new technologies such as TGV (Tumble Generated Valve) and EGR (Exhaust Gas Recirculation) cooling. Fuji Heavy also rolls in its own brand of variable valve timing called AVCS (Active Valve Control System).
Of course, the new-generation boxers also gain the requisite reduction in mass, increase in efficiency, and decrease in friction that we expect from a revision to a modern gasoline engine. There is also an uprated cooling system and more efficient oil pump that help the engines to operate at their peak.
Actual power, emissions, and fuel efficiency numbers have yet to be published. The new boxer will debut on the next revision to the Subaru Forester before going on to become the main engines in Subaru's lineup.