The SUBARU EF12E is a 1,189 cc, inline-four petrol engine produced between 1984 and 1994. It features a SOHC valvetrain, carburetted fuel delivery, and cast-iron block construction, delivering reliable performance for compact and city-focused applications. In standard tune it produced 55 kW (75 PS) with 100 Nm of torque, forming part of Subaru's EF engine family.
Fitted to models such as the Subaru Rex, Vivio, and Sumo, the EF12E was engineered for urban drivability, fuel economy, and emissions compliance. Emissions compliance was achieved through exhaust gas recirculation (EGR) and air injection, allowing all units to meet early Euro 1 standards (VCA UK Type Approval #VCA/EMS/9238).
One documented concern is premature camshaft wear, highlighted in Subaru Service Information Bulletin 86-NA-040. This issue is linked to inadequate lubrication at the camshaft lobes during sustained high-RPM operation and extended oil change intervals. In 1988, Subaru revised the oil pump design and updated lifter profiles to improve durability, marking a key update during the engine's production run.
Subaru
All production years (1984–1994) meet early Euro 1 emissions standards (VCA UK Type Approval #VCA/EMS/9238).
The SUBARU EF12E is a 1,189 cc inline-four petrol engine engineered for compact and city cars (1984–1994). It combines robust SOHC architecture with carburetted fuel delivery to deliver dependable urban driving. Designed to meet early European emissions standards, it represents a durable iteration of Subaru's small-displacement engine platform.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,189 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-4, SOHC, 8-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 70.0 mm × 77.0 mm | |
| Power output | 55 kW (75 PS) @ 6,000 rpm | |
| Torque | 100 Nm @ 3,600 rpm | |
| Fuel system | Single-barrel carburettor | |
| Emissions standard | Euro 1 | |
| Compression ratio | 9.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Gear-driven (non-interference design) | |
| Oil type | SAE 10W-30 (API SF) | |
| Dry weight | 98 kg |
The gear-driven SOHC design demands strict adherence to 15,000 km oil change intervals to prevent camshaft and lifter wear. SAE 10W-30 API SF oil is essential due to its stability under sustained load conditions. Extended warm-up periods are recommended before aggressive driving to ensure proper oil circulation. The carburettor system is sensitive to cold starts; use of winter-grade petrol meeting EN 228 standards prevents icing and mixture imbalance. Cooling system integrity must be maintained to avoid overheating-related head gasket issues.
Oil Specs: Requires SAE 10W-30 API SF specification (Subaru Service Manual 1984-0371).
Emissions: Certified to early Euro 1 standards (VCA #VCA/EMS/9238).
Power Ratings: Measured under SAE J1349 standards. 55 kW output requires 87 RON fuel (Subaru TIS Doc. A24716).
Subaru Technical Information System (TIS): Docs A24716, A25168, SIB 86-NA-040
VCA Type Approval Database (VCA/EMS/9238)
SAE International: J1349 Engine Power Certification Standards
The SUBARU EF12E was used across Subaru's Rx and Vx platforms with transverse mounting. This engine received platform-specific adaptations-shortened intake manifolds in the Rex and revised cooling routing in the Vivio-and from 1988 the facelifted Sumo models adopted updated ECU calibration, creating minor software differences. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped vertically on the left-side engine block near the exhaust manifold (Subaru TIS A25116). The 8th digit of the VIN indicates engine family ('E' for EF series). Pre-1988 models have silver valve covers with black gasket seals; post-1988 units use black valve covers. Critical differentiation from EF10: Original EF12E has Mikuni carburettor with manual choke, while EF10 uses automatic choke. Service parts require production date verification—lifters before 09/1987 are incompatible with later revisions due to internal redesign (Subaru SIB 86-NA-040).
The EF12E's primary reliability risk is camshaft and lifter wear, with elevated incidence in sustained highway driving with frequent short trips. Internal Subaru quality reports from 1986 indicated a significant share of pre-1988 engines required camshaft replacement before 100,000 km, while NHTSA field reports show drivability faults contributing to emissions-related failures. Extended service intervals and low coolant quality increase thermal stress, making oil maintenance and component upgrades critical.
Analysis derived from Subaru technical bulletins (1984–1994) and NHTSA field reports (1986–1993). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about SUBARU EF12E.
Comprehensive technical documentation and regulatory references
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SUBARU Official Site
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EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
GOV.UK: Vehicle Approval & V5C
UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
UK type-approval authority for automotive products.
Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
WLTP and RDE testing procedures for emissions certification.
GOV.UK: Vehicle Approval
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
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