The current, second-generation Subaru boxer four-cylinder engine has been in production for over two decades, so needless to say a replacement has been a long time coming. And now it's here, with Subaru completely redesigning its staple powerplant to help the company move forward in an increasingly fuel-efficiency-focused world.
Available in both a 2.o-liter and 2.5-liter displacement, at first it seems there's little new with this four-cylinder engine, but it's the details that matter most. With a new bore and stroke, the porting has been redesigned, while the pistons are lighter and the con rods help reduce internal friction. Also included is Subaru's AVCS (Active Valve Control System) variable valve timing system. Subaru claims these advances have resulted in a 10 percent improvement in fuel economy.
Another benefit of the new design are separate cooling ducts for the block and heads.
No performance numbers have been released but Subaru claims the new design makes for advances in driving performance with, "acceleration in all speed ranges" while stating that the new engine has been designed to work with advancing technology – likely meaning it's capable of featuring a direct-injection system, as well as adaptable to a hybrid setup.
More: Subaru Reveals More Efficient Third-Gen Boxer Engine