

Primary engineering on the EJ series was done by Masayuki Kodama, Takemasa Yamada and Shuji Sawafuji of Fuji Heavy Industries, Subaru's parent company. These engines are commonly used in light aircraft, kit cars and engine swaps into air-cooled Volkswagens, and are also popular as a swap into copy wasserboxer engined Volkswagen T3/Vanagon. Naturally aspirated and turbocharged versions are available, ranging from 96 to 320 hp (72 to 239 kW 97 to 324 PS). The EJ series was the mainstay of Subaru's engine line, with all engines of this series being 16-valve horizontal flat-fours, with configurations available for single, or double-overhead camshaft arrangements ( SOHC or DOHC).

They were introduced in 1989, intended to succeed the previous Subaru EA engine. The Subaru EJ engine was a series of four-stroke automotive engines manufactured by Subaru.
