🏷️ Basic Information Identification Make: Subaru Model: Impreza WRX STI Year: 2015 Codes Chassis Code: GVB (Hatchback), GRF (Hatchback) Engine Code: EJ257 👋 Introduction Market Position Segment: Performance Compact Sedan/Hatchback (WRC Homologation Special) Target Audience: Enthusiasts, performance drivers, rally sport fans Competitive Analysis Key Competitors: Mitsubishi Lancer Evolution, Volkswagen Golf GTI, Ford Focus RS, Honda Civic Type R Key Features Performance Focus: Symmetrical All-Wheel Drive, turbocharged Boxer engine, performance-tuned suspension, aggressive styling Manual Value Proposition: Provides in-depth, professional-level repair and maintenance guidance for the specialized WRX STI variant 📋 Manual Details Coverage Areas Major Topics: Engine, Transmission, Drivetrain, Suspension, Brakes, Electrical Systems, HVAC, Bodywork, Diagnostics, Maintenance, Repair, Troubleshooting Page Count Estimated Pages: 2000+ Manual Type Type: Service and Repair Workshop Manual Language Language: English Format Format: Digital (PDF) 📖 Manual Coverage Systems Covered Engine Mechanical: Engine assembly, cylinder heads, pistons, crankshaft, timing belt/chain, lubrication system, cooling system Engine Performance: Fuel injection system, ignition system, turbocharger, intercooler, emission control systems (EVAP, secondary air injection) Transmission Drivetrain: Manual transmission (TY856), clutch system, all-wheel drive system (DCCD), differentials (front, rear, center), driveshafts, axles Suspension Steering: Front and rear suspension components (struts, springs, control arms, sway bars), power steering system, steering rack Brakes: Brake system components (calipers, rotors, pads, master cylinder, ABS), parking brake Electrical Systems: Wiring diagrams, battery, charging system, starting system, lighting (headlights, taillights, interior), power windows, mirrors, central locking HVAC: Air conditioning system, heating system, ventilation, blower motor, climate control unit Bodywork Interior: Exterior panels, doors, hood, trunk, bumpers, interior trim, seats, airbags Diagnostics: OBD-II diagnostic codes, troubleshooting procedures, sensor testing, ECU diagnosis Procedures Included Scheduled Maintenance: Oil changes, filter replacements, fluid flushes, spark plug replacement, inspections Engine Repair: Engine rebuilds, head gasket replacement, turbocharger overhaul, timing belt/chain replacement procedures Transmission Service: Transmission fluid change, clutch replacement, drivetrain component inspection and repair Brake Service: Brake pad and rotor replacement, brake fluid flush, caliper overhaul Electrical Troubleshooting: Fault finding for various electrical systems using wiring diagrams and diagnostic steps Body Repair: Panel replacement, dent repair, bumper repair, door mechanism adjustment Technical Depth Depth: Comprehensive from basic maintenance to complex overhauls and diagnostics, suitable for professional mechanics and experienced DIYers 📊 Manual Specifications File Format File Type: PDF Searchability: Searchable text content Printability: Printable pages Print Quality Image Resolution: High-resolution diagrams and illustrations Binding Type Binding: N/A (Digital Format) Paper Type Paper: N/A (Digital Format) ⚙️ Engine Specifications Primary Engine Engine Type: 2.5L Turbocharged DOHC Flat-4 (EJ257) Bore X Stroke: 99.5 mm x 79.0 mm Compression Ratio: 8.2:1 Valve Train: Dual Overhead Camshafts (DOHC), 4 valves per cylinder Performance Horsepower: 305 hp @ 6000 rpm Torque: 290 lb-ft @ 4000 rpm Fuel System Fuel Delivery: Multi-point Fuel Injection (MPI) with Electronic Throttle Control Fuel Type: Premium Unleaded Gasoline (91 Octane or higher recommended) Turbocharging Turbocharger Model: IHI VF48 Intercooler: Top-mounted air-to-air intercooler 🔧 Transmission Standard Type: 6-speed Manual Transmission (TY856) Optional Type: N/A for WRX STI model year 2015 Features Dccd: Driver Controlled Center Differential (DCCD) with automatic and manual modes Differentials: Helical LSD front differential, Torsen LSD rear differential 📐 Dimensions Exterior Length: 173.8 inches (Hatchback) Width: 70.7 inches Height: 58.1 inches (Hatchback) Wheelbase: 104.9 inches Weights Curb Weight: Approx. 3,373 lbs (Hatchback) Gross Vehicle Weight Rating: Not specified, consult vehicle label 🛡️ Safety Features Ratings NHTSA Overall Rating: 5-Star (2015 Model Year Impreza) Active Features ABS: 4-wheel Anti-lock Braking System (ABS) Traction Control: Vehicle Dynamics Control (VDC) with Sport Mode AWD: Subaru Symmetrical All-Wheel Drive Passive Features Airbags: Front dual-stage airbags, front side-impact airbags, side-curtain airbags, driver's knee airbag Seatbelts: 3-point front and rear seatbelts with pretensioners and force limiters 💡 Technology Features Infotainment Head Unit: Standard touchscreen infotainment system with CD player, AM/FM/HD Radio, USB/iPod control, Bluetooth connectivity Driver Assistance Vehicle Dynamics Control: Advanced VDC system with Sport Mode for enhanced handling and stability control All Wheel Drive Control: DCCD allows driver to adjust center differential lockup for various driving conditions. Connectivity Bluetooth: Bluetooth hands-free phone and audio streaming 🔧 Maintenance Service Intervals Oil Change Interval: Every 3,750 miles or 6 months (severe duty) / 7,500 miles or 12 months (normal duty) Engine Oil Type: SAE 5W-30, API SN/SP, ILSAC GF-5/GF-6A certified synthetic oil recommended Oil Filter Part Number: Subaru: 15208AA100, Aftermarket: Wix 57712, K&N HP-3001 Fluid Specifications Coolant Type: Subaru Super Coolant (Blue) or equivalent silicate-free, long-life coolant Transmission Fluid Type: Subaru Extra MT (75W-90 GL-5) for 6MT Differential Fluid Type: Subaru Extra-S (75W-90 GL-5) for Front and Rear Diffs, and DCCD Center Diff Brake Fluid Type: DOT 3 or DOT 4 brake fluid Known Issues Engine Ringland Failure: Potential for ringland failure on piston #4 due to detonation, especially with aggressive tuning or poor fuel. Manual details proper diagnosis and repair. Clutch Wear: High-performance clutch can wear faster under aggressive driving. Manual provides clutch inspection and replacement procedures....