Engine Code Reference

Subaru Boxer Engine Codes

EA / EJ / FA-FB flat-fours — for Subaru identification and aircooled VW conversion planning.

How to read the code

Subaru codes are cast or stamped on the right-rear bellhousing flange — letters (EA / EJ / FA / FB) followed by displacement in decilitres (e.g. EJ20 = 2.0 L).
Suffix letters indicate spec: T/G/K/Y/X = turbo variants, no suffix = naturally aspirated.
For VW conversions, EJ22 and early EJ20 SOHC are the workshop favourites — simpler engine management, fewer head-gasket issues than Phase II EJ25.
Power figures are factory-quoted at the listed market; JDM 'gentleman's agreement' cars are capped at 276 bhp regardless of true output.

Code	cc	bhp	Years	Application	Notes
EA71	1595	67	1976–89	Leone, Brat, early DL/GL	SOHC 8v, carburettor, pushrod-style timing belts
EA81	1781	73–95	1980–94	Leone, Brat, MV, Loyale	SOHC 8v, carb or SPFI; common VW Bay/T25 swap base
EA82	1781	84–115	1985–94	Leone, GL-10, RX, XT, Loyale	SOHC/DOHC 16v, MPFI or turbo; longer block than EA81
EJ15	1493	97	1994–07	Impreza (JDM), Pleo van	SOHC 16v, JDM domestic only
EJ16	1597	95–105	1995–05	Impreza (EU)	SOHC 16v, MPFI
EJ18	1820	110	1990–94	Legacy, Impreza early	SOHC 16v, hydraulic lifters
EJ20	1994	115–148	1989–10	Legacy, Impreza, Forester NA	SOHC/DOHC NA versions — very popular T25/T3 swap
EJ22	2212	130–160	1990–01	Legacy, Impreza 2.2	SOHC 16v MPFI; 'Phase 1' bulletproof reputation
EJ25	2457	155–173	1995–11	Legacy, Forester, Outback, Impreza	DOHC then SOHC; head gasket prone on Phase II
EJ20G	1994	237–276	1992–98	Impreza WRX, Legacy GT	DOHC turbo, closed-deck early WRX/STI
EJ20K	1994	276	1996–98	Impreza WRX STi v3/v4	DOHC turbo, semi-closed deck
EJ207	1994	276–316	1998–19	Impreza WRX STi (JDM/EU)	DOHC AVCS turbo, factory-rated cap
EJ20Y/EJ20X	1994	247–276	2003–09	Legacy GT, Forester XT	Twin-scroll AVCS turbo
EJ255	2457	224–265	2004–14	Forester XT, Legacy GT, US WRX	SOHC turbo, US-market 2.5 turbo
EJ257	2457	300	2004–21	Impreza WRX STi (US/EU)	DOHC AVCS turbo, semi-closed deck
FB20	1995	148	2011–	Impreza, Forester, XV	DOHC dual-AVCS, chain-drive, low-friction
FB25	2498	170	2010–	Forester, Legacy, Outback	DOHC dual-AVCS, chain-drive
FA20	1998	200	2012–	BRZ, Toyota GT86, Levorg	DOHC D-4S, direct + port injection
FA20DIT	1998	268	2014–	WRX, Levorg, Forester XT	Direct-injection turbo, chain-drive
FA24	2387	228–260	2019–	Ascent, Outback XT, BRZ '22+	DI turbo or NA depending on variant

Sources: Subaru factory service manuals (FSM), JDM and EU brochures, and the SubaruDieselCrew / NASIOC engine reference threads. Many codes had multiple revisions (Phase I/II) — confirm against the engine number and ECU code before ordering parts.

Power figures are factory-quoted SAE/DIN bhp at the listed market. Many codes were used across multiple model years and markets — always cross-reference the engine number, serial range and the M-plate before ordering parts.