The Subaru EJ engine is a series of automotive engines manufactured by Subaru

Subaru

; is the automobile manufacturing division of Japanese transportation conglomerate Fuji Heavy Industries .Subaru is internationally known for their use of the boxer engine layout popularized in cars by the Volkswagen Beetle and Porsche 911, in most of their vehicles above 1500 cc as well as...

 and introduced in 1989, intended to succeed the previous Subaru EA engine

Subaru EA engine

The Subaru EA engine is a series of automobile internal combustion engines manufactured by Subaru, a division of Fuji Heavy Industries. All EA series engines are of a flat-4 design....

. The EJ series is the mainstay of Subaru's engine line, with all engines of this series being 16-valve flat-4 horizontal, with configurations available for single-, or double-overhead camshaft arrangements (SOHC or DOHC). Naturally aspirated and turbocharged versions are available, ranging from around 120 horsepower in early non-turbo Legacies, to 320 horsepower in the Impreza WRX STI.