For over three decades, the EJ20 was the workhorse of Subaru, as the 2.0-liter flat four boxer engine would power models throughout the brand's lineup. However, it's the engine's generations of ...

How boxer engines work, why they’re not just “flat” engines, and a 120-year evolution traced from the 1899 Benz to the latest Porsche and Subaru boxers. Boxer engines feature flat, opposing pistons ...