The Subaru EJ20 is a 1,994 cc, flat-four turbocharged petrol engine produced between 2010 and 2019. It features dual overhead camshafts (DOHC), 16-valve configuration, and Subaru's Dual VVT system with multi-point fuel injection. In standard tune, it delivered 191 kW (260 PS) at 5,600 rpm and 350 Nm of torque at 2,400–5,200 rpm, offering balanced performance and refinement for enthusiast applications.
Fitted to models including the WRX STI and Japanese-market Legacy GT, the EJ20 was engineered for high-performance driving dynamics and track capability. Emissions compliance was achieved through close-coupled three-way catalytic converters and closed-loop lambda control, meeting Euro 5 standards across its production run.
One documented reliability concern is premature turbocharger bearing wear, which could lead to oil leaks, loss of boost, or catastrophic turbo failure. This issue, highlighted in Subaru Service Information Bulletin SIB-EJ-020, is attributed to inadequate lubrication under sustained high-load operation and extended oil change intervals. In 2015, Subaru introduced an upgraded turbocharger with improved bearing materials and revised oil feed design to reduce stress.
Production years 2010–2019 meet Euro 5 emissions standards (VCA UK Type Approval #VCA/EMS/4036).
The Subaru EJ20 is a 1,994 cc flat-four turbocharged petrol engine engineered for high-performance applications (2010–2019). It combines turbocharging with DOHC valvetrain to deliver responsive power and elevated drivability. Designed to meet Euro 5 standards, it balances track-ready performance with road legality.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,994 cc | |
| Fuel type | Petrol | |
| Configuration | Flat-4, DOHC, 16-valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 92.0 mm × 75.0 mm | |
| Power output | 191 kW (260 PS) @ 5,600 rpm | |
| Torque | 350 Nm @ 2,400–5,200 rpm | |
| Fuel system | Sequential multi-port fuel injection | |
| Emissions standard | Euro 5 | |
| Compression ratio | 8.2:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | IHI VF48 ball-bearing turbocharger | |
| Timing system | Double-row roller chain (DOHC) | |
| Oil type | Subaru 5W-30 (API SN) | |
| Dry weight | 138 kg |
The turbocharged flat-four provides strong mid-range torque ideal for spirited driving but requires strict adherence to 10,000 km oil change intervals to prevent turbo and valvetrain degradation. Subaru 5W-30 oil is critical due to its formulation supporting high-RPM stability and turbo lubrication. Extended idling after hard use increases thermal stress on the turbo bearings. The 2015 update with revised turbo internals significantly improved durability; pre-2015 engines should verify turbo condition and consider preventative upgrades per Subaru SIB SIB-EJ-020.
Oil Specs: Requires Subaru 5W-30 specification (Subaru SIB SIB-EJ-020). Supersedes ACEA A5/B5 requirements.
Emissions: Euro 5 certification applies to all EJ20 models (2010–2019) (VCA Type Approval #VCA/EMS/4036).
Power Ratings: Measured under SAE J1349 standards. Output consistent across EU fuel grades (RON 95–98).
Subaru Technical Information System (TIS): Docs A29400, A29401, A29402, SIB SIB-EJ-020
VCA Type Approval Database (VCA/EMS/4036)
SAE International: J1349 Engine Power Measurement Standard
The Subaru EJ20 was used across Subaru's WRX STI/Legacy GT platforms with longitudinal mounting and no licensed external applications. This engine received platform-specific adaptations-higher-flow intercooler in the WRX STI and revised intake manifolds in the Legacy GT-and from 2015 the updated turbocharger with improved bearing materials, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front passenger side of the engine block near the cylinder head (Subaru TIS A29400). The 8th VIN digit indicates engine family ('E' for EJ series). Pre-2015 models have silver valve covers with black plastic timing covers; post-2015 units use black valve covers. Critical differentiation from FB20: EJ20 uses a turbocharged 2.0L flat-four, while FB20 is a naturally aspirated 2.0L flat-four petrol. Service parts require production date verification - turbochargers before 09/2015 are incompatible with later revisions due to internal redesign (Subaru SIB SIB-EJ-020).
The EJ20's primary reliability risk is turbocharger bearing wear on early builds, with elevated incidence in vehicles with extended service intervals. Internal Subaru quality reports from 2018 indicated a significant number of pre-2015 units required turbo replacement before 100,000 km, while UK DVSA records show boost-related faults as a top cause of drivability complaints in Subaru turbo petrol models. Extended service intervals and aggressive driving increase thermal stress, making oil quality and schedule adherence critical.
Analysis derived from Subaru technical bulletins (2010–2019) and UK DVSA failure statistics (2011–2019). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about SUBARU EJ20.
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