Introduction. Subaru's EJ20G was a turbocharged, 2.0-litre horizontally-opposed (or 'boxer') four-cylinder petrol engine. For Australia, the EJ20G engine powered the GC/GM Impreza WRX from 1994 to 1996; key features of the EJ20G engine included its: Die-cast aluminium block and cylinder head; Double overhead camshafts (belt-driven);