Segment:
Performance Compact/Sport Compact
Competitors:
Mitsubishi Lancer Evolution, Honda Civic Si, Mazdaspeed3, Volkswagen GTI
Performance Orientation:
Tuned turbocharged engine, Symmetrical All-Wheel Drive, performance-oriented chassis, aggressive styling
Rally Heritage:
Direct lineage from Subaru's World Rally Championship success
Target Audience:
Enthusiasts, DIY mechanics, professional technicians
Benefit:
Empowers owners and technicians to maintain, diagnose, and repair the vehicle to manufacturer standards.
Markets Covered:
Global (primarily North America, Europe, Japan)
Trim Levels Covered:
WRX STi (all performance variants)
Estimated Pages:
1500-2500 (Typical for comprehensive workshop manuals)
Type:
Workshop Service Repair Manual
Powertrain:
Engine (EJ257), Turbocharger, Intercooler, Fuel System, Exhaust System, Drivetrain (Symmetrical AWD, DCCD, Differentials), Transmission (6-speed Manual)
Chassis:
Suspension (Front/Rear), Steering, Brakes (ABS, Brembo), Wheels, Tires
Electrical:
Wiring Diagrams, Battery, Charging System, Ignition System, Lighting, Instrumentation, Audio System, ECU Control
Body:
Exterior Body Panels, Interior Trim, Doors, Windows, Seats, HVAC System
Maintenance:
Oil Changes, Filter Replacements, Spark Plug Service, Fluid Checks and Replenishments, Belt Inspections
Diagnostics:
Troubleshooting Guides, DTC (Diagnostic Trouble Code) Interpretation, Component Testing Procedures
Repair:
Engine Rebuilds, Transmission Overhauls, Suspension Component Replacement, Brake System Repair, Electrical Component Diagnosis and Repair
Installation:
Component Installation Guides, Aftermarket Part Integration Considerations (where applicable to service)
Depth:
Comprehensive (from basic maintenance to complete overhaul and advanced diagnostics)
Accuracy:
Dealership-Level Accuracy and Detail
Engine Type:
Horizontally Opposed (Boxer) Turbocharged DOHC 16-Valve
Displacement:
2.5 Liters (2457 cc)
Bore X Stroke:
99.5 mm x 79.0 mm (approx.)
Fuel Type:
Premium Unleaded Gasoline (91 Octane or higher recommended)
Horsepower:
305 hp @ 6000 rpm (approx., varies by market/spec)
Torque:
290 lb-ft @ 4000 rpm (approx., varies by market/spec)
Injection Type:
Sequential Multi-Port Fuel Injection (S-MPI)
Turbocharger:
IHI VF48 (twin-scroll turbocharger)
Engine Management System:
Subaru Select Monitor (SSM) compatible ECU
Cooling System:
Water-cooled with intercooler
Type:
6-Speed Manual Transmission
Dccd:
Driver Controlled Centre Differential (DCCD) with auto mode
Type:
Not applicable for WRX STi (Manual only)
All Wheel Drive:
Symmetrical All-Wheel Drive (SAWD) with front helical limited-slip differential (LSD) and rear mechanical LSD
Manual Transmission Fluid:
Subaru Genuine Gear Oil (e.g., API GL-5, SAE 75W-90)
Length:
4,415 mm (Hatchback)
Height:
1,475 mm (Hatchback)
Track Width Front:
1,530 mm
Track Width Rear:
1,535 mm
Curb Weight:
Approx. 1,490 kg (Hatchback)
Gross Vehicle Weight Rating:
N/A (Typically not specified in service manuals for this level of detail)
Cargo Volume:
290 Liters (Hatchback, to parcel shelf)
NHTSA Overall Rating:
Not directly comparable for performance variants, focus is on specific crashworthiness
Traction Control:
Yes (Subaru Vehicle Dynamics Control - VDC)
ABS:
Yes (Anti-lock Braking System with EBD)
Airbags:
Driver and Front Passenger Airbags, Side Airbags, Curtain Airbags
Seat Belts:
Pretensioner and Load Limiter Seatbelts
Body Structure:
Reinforced chassis for enhanced impact protection
Head Unit:
Factory-installed AM/FM/CD/MP3 audio system, optional navigation system.
Speakers:
Premium audio system with subwoofer (optional/standard on certain trims).
Stability Control:
Subaru Vehicle Dynamics Control (VDC) with Sport Mode
Auxiliary Input:
Standard auxiliary audio input jack.
Dccd:
Driver Controlled Centre Differential for adjustable torque split.
Si-Drive:
Subaru Intelligent Drive (SI-DRIVE) with Intelligent, Sport, and Sport Sharp modes (controls engine mapping and throttle response).
Oil Change Interval:
Every 3,750 miles or 6 months (severe driving), 7,500 miles or 12 months (normal driving) - Consult manual for specific recommendations.
Air Filter Replacement:
Every 15,000 miles or 12 months (inspect more frequently).
Spark Plug Replacement:
Every 30,000 miles (NGK Iridium plugs recommended)
Engine Oil Type:
5W-30 Synthetic (API SN/SP, ILSAC GF-5/GF-6A) - Check manual for specific viscosity and API rating.
Coolant Type:
Subaru Super Coolant (Blue) - mixture 50/50 with distilled water.
Brake Fluid Type:
DOT 3 or DOT 4 High-Temperature Brake Fluid
Engine Internal:
Ringland failure (especially with aggressive tuning), valve seal wear, oil consumption.
Turbocharger:
Wastegate rattle, bearing wear.
Clutch:
Wear and tear, especially in high-performance driving.
Suspension:
Worn bushings, premature shock absorber failure in some cases.
