Subaru's EJ257 was a turbocharged, 2.5-litre horizontally-opposed (or 'boxer') four-cylinder engine. For Australia, the EJ257 engine was introduced in the Subaru GD Impreza WRX STi in 2005 and subsequently powered the GE/GH Impreza WRX STi and V1 WRX.Effectively replacing the 2.0-litre EJ207 engine, the EJ257 engine was a member of Subaru’s Phase II EJ engine family; key features included its: