🏷️ Basic Information

Make:

Subaru

Model:

Impreza WRX STI

Year:

2012

Chassis Code:

GVB/GRB

Engine Code:

EJ257

👋 Introduction

Segment:

Performance Compact Sedan/Hatchback, Rally-inspired Sport Compact

Positioning:

The pinnacle of the Impreza line, focused on performance, handling, and motorsport heritage, targeting enthusiasts seeking a capable daily driver with track-day potential.

Competitors:

Mitsubishi Lancer Evolution, Volkswagen Golf R, Ford Focus RS (depending on market availability)

Performance Attributes:

Symmetrical All-Wheel Drive (SAWD), Driver Controlled Centre Differential (DCCD), performance-tuned suspension, powerful turbocharged engine, aerodynamic body kit.

Handling Dynamics:

Renowned for its exceptional grip, stability, and driver engagement, thanks to its AWD system and chassis tuning.

📋 Manual Details

Coverage Type:

Comprehensive Service and Repair

Target Audience:

Professional Mechanics and Enthusiast Owners

Estimated Pages:

2000+

Type:

Factory Service Manual / Workshop Manual

Language:

English

Format:

Digital (PDF)

📖 Manual Coverage

Engine:

2.5L turbocharged Boxer Engine (EJ257), including diagnosis, repair, and overhaul of engine mechanicals, lubrication, cooling, fuel injection, ignition, and emissions systems.

Transmission:

6-speed manual transmission (TY856WRJAA), including clutch system, gearbox overhaul, driveline components (driveshafts, differentials), and AWD system.

Brakes:

Brake system (front/rear ventilated discs, Brembo calipers), ABS, EBD, and brake system diagnostics and repair.

Suspension:

Front MacPherson strut and rear double-wishbone suspension, shock absorbers, springs, bushings, alignment specifications, and STI-specific tuning.

Steering:

Power-assisted rack and pinion steering system, steering column, and alignment.

Electrical:

Complete electrical system, including battery, charging system, starter, lighting, wiring diagrams, fuses, relays, ECU, sensors, immobilizer, and infotainment.

Body:

Body construction, exterior panels, interior trim, doors, windows, locks, HVAC system, and structural repair guidelines.

Diagnostics:

On-Board Diagnostics (OBD-II), diagnostic trouble codes (DTCs), scan tool usage, and troubleshooting procedures for all major systems.

Maintenance:

Scheduled maintenance, fluid changes (oil, coolant, brake, transmission, differential), filter replacements, spark plug service, belt inspections and replacement.

Repair:

Engine rebuild procedures, transmission overhaul, brake caliper replacement, suspension component repair, turbocharger servicing, clutch replacement, electrical component repair.

Troubleshooting:

System-specific troubleshooting guides based on symptoms, including engine performance issues, electrical gremlins, transmission engagement problems, and braking anomalies.

Diagnostics:

Step-by-step diagnostic procedures for identifying faults using measurement tools, schematics, and logical reasoning.

Disassembly Assembly:

Detailed instructions for the removal and installation of all major components and sub-assemblies.

Depth Level:

Factory Level - Covers everything from basic maintenance to complete engine and transmission rebuilds, including internal component specifications and tolerances.

📊 Manual Specifications

Format Details:

Searchable PDF document with high-resolution diagrams and illustrations.

Quality:

High-resolution scans of original factory manuals, ensuring clarity of text and images.

Binding:

N/A (Digital Format)

Type:

N/A (Digital Format)

⚙️ Engine Specifications

Engine Type:

Horizontally Opposed (Boxer) 4-Cylinder, Turbocharged

Displacement:

2.5 Liters (2457 cc)

Bore X Stroke:

99.5 mm x 80.0 mm

Compression Ratio:

8.4:1

Valve Train:

DOHC, 16 Valves, Subaru Variable Valve Lift and Timing (VVL-i)

Fuel Delivery:

Multi-point Fuel Injection (MPI) with Turbocharging

Horsepower:

305 HP @ 6000 RPM (SAE Net)

Torque:

290 lb-ft @ 4000 RPM (SAE Net)

Recommended Fuel:

Premium Unleaded Gasoline (91 Octane or higher)

Fuel Tank Capacity:

15.9 US Gallons (60 Liters)

🔧 Transmission

Transmission Type:

6-Speed Manual Transmission

Gear Ratios:

1st: 3.636, 2nd: 2.055, 3rd: 1.461, 4th: 1.066, 5th: 0.878, 6th: 0.769

Final Drive Ratio:

3.545

All Wheel Drive:

Symmetrical All-Wheel Drive (SAWD) with Driver Controlled Centre Differential (DCCD)

Differential Type:

Front: Helical limited-slip, Rear: Viscous coupling limited-slip

📐 Dimensions

Length:

179.7 inches (4565 mm)

Width:

70.7 inches (1796 mm)

Height:

57.1 inches (1450 mm)

Wheelbase:

103.0 inches (2615 mm)

Front Track:

60.2 inches (1529 mm)

Rear Track:

60.4 inches (1534 mm)

Ground Clearance:

5.0 inches (127 mm)

Curb Weight:

3417 lbs (1550 kg) for Sedan, 3362 lbs (1525 kg) for Hatchback

Gross Vehicle Weight Rating:

4431 lbs (2010 kg)

🛡️ Safety Features

NHTSA Overall Rating:

Not rated specifically for 2012 WRX STI, but related Impreza models generally performed well. Refer to specific model year for exact data.

ABS:

Anti-lock Braking System (ABS) with Electronic Brake-force Distribution (EBD) and Brake Assist

Traction Control:

Vehicle Dynamics Control (VDC) with traction control capabilities

Stability Control:

Standard Vehicle Dynamics Control (VDC) system

Airbags:

Front dual-stage airbags, front side-impact airbags, side-curtain airbags

Seatbelts:

3-point height-adjustable front seatbelts with pre-tensioners and load limiters, 3-point rear seatbelts

Child Seat Anchors:

LATCH (Lower Anchors and Tethers for CHildren) system

💡 Technology Features

Head Unit:

Standard AM/FM/CD/MP3 stereo with auxiliary input, USB port, Bluetooth connectivity, and steering wheel controls. Optional navigation system available.

Display:

Multi-function display for vehicle information and climate control.

Cruise Control:

Standard Cruise Control

Keyless Entry:

Standard Keyless Entry with Remote Keyless Entry and Immobilizer

Bluetooth:

Bluetooth hands-free calling and audio streaming

🔧 Maintenance

Oil Change Interval:

Every 3,750 miles (6,000 km) or 3 months, whichever comes first (severe driving conditions), or 7,500 miles (12,000 km) or 6 months (normal driving conditions).

Air Filter Replacement:

Every 15,000 miles (24,000 km)

Spark Plug Replacement:

Every 30,000 miles (48,000 km)

Timing Belt Interval:

Not applicable (uses a timing chain)

Engine Oil Type:

SAE 5W-30 Synthetic (API SN or ILSAC GF-5 certified). Refer to manual for specific viscosity under extreme conditions.

Engine Oil Capacity:

5.7 US Quarts (5.4 Liters) with filter change

Coolant Type:

Subaru Super Coolant (Blue) or equivalent Subaru-compatible long-life coolant. Never use conventional green coolant.

Transmission Fluid Type:

Subaru Extra-S Gear Oil (75W-90 GL-5) for manual transmission and differentials. Check manual for specific AWD unit fluid.

Brake Fluid Type:

DOT 3 or DOT 4

Engine Reliability:

Head gasket failures (though less common on EJ257 than earlier EJ25), piston ring land failures under high stress/poor tuning, turbocharger seal failures.

Clutch Wear:

Clutch wear can be accelerated with aggressive driving or frequent dumping of the clutch.

Suspension Wear:

Bushing wear and eventual failure over time, especially under hard driving. Wheel bearing failures can also occur.

Electrical Gremlins:

While generally reliable, some owners report minor electrical issues or sensor failures.

📚 Vehicle History

Rally Roots:

Subaru's deep and successful history in the World Rally Championship (WRC) with iconic drivers like Colin McRae and Petter Solberg.

Previous Generations:

The 2012 model represents the fourth generation of the WRX STI, evolving from its rally homologation roots. This generation marked a transition away from the Impreza naming convention in some markets for the STI variant.

Production Location:

Ota City, Gunma Prefecture, Japan

🏆 Awards & Recognition

Car And Driver Λογή:

Frequently cited by automotive publications like Car and Driver for its performance and handling characteristics, often appearing on '10Best' lists in its category.

Motorsport Accolades:

Directly benefits from Subaru's continuous motorsport development, particularly in rally disciplines, translating to superior chassis and drivetrain engineering.