🏷️ Basic Information Identification Make: Subaru Model: Impreza WRX STI Year: 2012 Generation Generation Code: GH/GR/GV Codes Chassis Code: GVB Engine Code Primary: EJ257 👋 Introduction Market Position Market Segment: Performance Compact Sedan/Hatchback Target Audience: Enthusiast drivers, performance tuning community, owners seeking in-depth DIY repair knowledge. Competitive Analysis Key Competitors 2012: Mitsubishi Lancer Evolution, Volkswagen Golf GTI, Ford Focus RS Key Features Performance Focus: Designed for owners of the rally-bred WRX STI, emphasizing its turbocharged boxer engine, symmetrical all-wheel drive, and performance-oriented chassis. Manual Utility: Provides factory-level repair procedures, diagnostic information, and maintenance schedules crucial for maintaining the optimal performance and longevity of the WRX STI. 📋 Manual Details Coverage Areas Coverage Scope: All Models/Engines/Trims Page Count Estimated Page Count: 2000+ Manual Type Manual Type: Workshop Repair Service Manual Language Language: English Format Format: PDF Download 📖 Manual Coverage Systems Covered Powertrain: Engine Mechanical, Engine Electrical, Fuel System, Ignition System, Exhaust System, Lubrication System, Cooling System, Turbocharger System, Transmission (Manual & Automatic), Drivetrain (AWD System, Differentials, Axles) Chassis: Suspension (Front & Rear), Steering System, Brake System (ABS, EBD), Wheels & Tires Body And Interior: Body Panels, Doors, Windows, Seats, Interior Trim, HVAC System, Body Electrical (Lighting, Wipers, Horn), Audio System, SRS Airbag System Procedures Included Maintenance Procedures: Oil Changes, Filter Replacements, Fluid Checks & Top-offs, Spark Plug Replacement, Belt Inspection & Replacement, Brake Pad/Rotor Replacement, Tire Rotation Repair Procedures: Engine Overhaul/Rebuild, Transmission Repair/Overhaul, Suspension Component Replacement, Brake Caliper/Master Cylinder Replacement, Turbocharger Replacement, Fuel Injector/Pump Replacement, Electrical Component Diagnosis & Replacement, Body Panel Repair/Replacement Troubleshooting Diagnostics: Diagnostic Trouble Codes (DTCs), Engine Performance Issues, Transmission Shifting Problems, Electrical System Faults, ABS/Traction Control Malfunctions, HVAC System Issues Technical Depth Technical Depth: Comprehensive: From basic maintenance and fluid changes to detailed engine, transmission, and electrical system diagnostics and repair procedures. Includes torque specifications, wiring diagrams, and component removal/installation instructions. 📊 Manual Specifications File Format File Format: PDF Print Quality Print Quality: High Resolution, Searchable Text, Bookmarked Sections Binding Type Binding Type: N/A (Digital Download) Paper Type Paper Type: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Engine Type: Horizontally Opposed (Boxer) Turbocharged DOHC 16-Valve Displacement Cc: 2457 Bore X Stroke Mm: 99.5 x 79.0 Compression Ratio: 8.4:1 Turbocharger Model: Mitsubishi TD05H-18G Intercooler Type: Top-mounted Air-to-Air Performance Horsepower Hp: 305 Torque Lb-Ft: 290 Fuel System Fuel Delivery: Multi-Point Fuel Injection (MPI) with Sequential Activation Fuel Type: Premium Unleaded Gasoline (91 Octane or Higher Recommended) Engine Management ECU Type: Subaru ECU (ECU Tuning/Remapping is common in STI modifications) 🔧 Transmission Standard Transmission Type: 6-Speed Manual Transmission (STI Specific) 'TS-Type' Optional Transmission Type: None (STI models were exclusively manual) Features Drivetrain Layout: Symmetrical All-Wheel Drive (AWD) with Driver Controlled Center Differential (DCCD) Differentials: Front Helical Limited-Slip Differential (LSD), Rear Mechanical Limited-Slip Differential (LSD) 📐 Dimensions Exterior Length Mm: 4415 Width Mm: 1795 Height Mm: 1470 Wheelbase Mm: 2650 Ground Clearance Mm: 135 Weights Curb Weight Kg: 1505 Gross Vehicle Weight Rating Kg: 1900 Towing Capacity Kg: 0 Cargo Trunk Volume Liters: 410 🛡️ Safety Features Ratings NHTSA Overall Rating: Not rated for this specific trim/year, but predecessor models achieved good ratings. IIHS Rating: Good (for frontal offset, side impact - general Impreza platform) Active Features Traction Control: Yes (VDC - Vehicle Dynamics Control) Electronic Stability Control: Yes (VDC) Anti Lock Brakes: Yes (ABS with EBD - Electronic Brake-force Distribution) Brake Assist: Yes Passive Features Airbags: Frontal Airbags, Side Airbags, Curtain Airbags Seatbelts: Pretensioners and Load Limiters for Front Seats Child Seat Anchors: LATCH System 💡 Technology Features Infotainment Head Unit Features: Standard AM/FM/CD/MP3 player with auxiliary input. Optional touchscreen navigation system with Bluetooth and iPod connectivity. Driver Assistance Cruise Control: Standard Limited Slip Differentials: Standard (Front Helical, Rear Mechanical, Center DCCD) Connectivity Bluetooth: Optional, dependent on infotainment system package. Performance Tech Dccd: Driver Controlled Center Differential allows manual adjustment of the front-to-rear torque split for varying driving conditions. 🔧 Maintenance Service Intervals Oil Change Interval Miles: 3,750 - 7,500 (depending on driving conditions, manual recommends 3,750 for severe use) Air Filter Replacement Miles: 15,000 - 30,000 Spark Plug Replacement Miles: 30,000 - 60,000 (Iridium plugs) Transmission Fluid Change Miles: 30,000 - 60,000 (Manual Transmission, AWD fluid also recommended) Brake Fluid Change Miles: 30,000 Fluid Specifications Engine Oil Type: SAE 5W-30 Synthetic (API SN or ILSAC GF-5 compliant) Engine Oil Capacity Liters: 4.8 (with filter) Transmission Fluid Type Manual: SAE 75W-90 (API GL-4 or GL-5) Transmission Fluid Type AWD Front Diff: SAE 75W-90 (API GL-5) Transmission Fluid Type Rear Diff: SAE 75W-90 (API GL-5) Coolant Type: Subaru Super Coolant (Blue) or equivalent Known Issues Engine Failures: Head gasket failures (less common on EJ257 than earlier EJ25s but still a concern), piston ringland failure (especially with aggressive tuning), thrown rods. Turbocharger Issues: Oil starvation leading to turbo failure, wastegate rattle. Suspension Wear: Premature wear of control arm bushings and...