Segment:
Compact performance sedan/hatchback (WRC homologation special)
Key Competitors:
Mitsubishi Lancer Evolution, Ford Focus RS, Honda Civic Type R (in later generations)
Performance Orientation:
Symmetrical All-Wheel Drive, turbocharged boxer engines, rally heritage
Manual Purpose:
Enables owners and technicians to perform diagnostics, maintenance, and repairs on a wide range of Impreza models and performance variants.
Coverage Breakdown:
1993-1996 WRX, 1997-1998 Impreza, 1999-2000 Impreza (P1), 2001-2002 Impreza (STI), and subsequent models up to 2009
Estimated Total Pages:
Thousands (estimated across multiple volumes)
Type:
Workshop Service Repair Manual
Format:
Digital (likely PDF, potentially searchable)
Powertrain:
Engine (EJ series), transmission (manual & automatic), drivetrain (AWD system, differentials), fuel system, exhaust system, cooling system, lubrication system
Chassis:
Suspension (front & rear), steering system, braking system (including ABS), wheels & tires
Body And Interior:
Body panels, interior trim, HVAC system, seats, airbags
Electrical:
Wiring diagrams, lighting, ignition system, starting & charging system, ECU, sensors, body control modules, infotainment systems
Maintenance:
Scheduled maintenance, fluid changes, filter replacements, belt inspections/replacements, spark plug services
Diagnostics And Troubleshooting:
Diagnostic trouble codes (DTCs), symptom-based troubleshooting guides, electrical circuit diagnostics
Repair And Overhaul:
Engine component disassembly/reassembly, transmission overhaul, brake caliper/rotor replacement, suspension component replacement, body panel repair/replacement
Technical Specifications:
Torque specifications, clearances, timing procedures, component tolerances, fluid capacities and types
Depth:
Comprehensive (from basic maintenance to full engine and transmission rebuilds, including electrical system diagnostics)
Engine Family:
Subaru EJ Series Boxer Engines
Displacement Range:
2.0L, 2.5L (turbocharged)
Horsepower Range:
Approx. 215 hp (WRX) to 300+ hp (STI, depending on generation and specific tune)
Torque Range:
Approx. 200 lb-ft to 300+ lb-ft (depending on generation and specific tune)
Induction:
Turbocharged, Intercooled (Sequential twin-turbo in early GC generation WRX)
Fuel Delivery:
Electronic Fuel Injection (EFI)
ECM Type:
ECU (Engine Control Unit) - various iterations throughout the years
Pistons And Rods:
Forged components in STI and performance WRX models for enhanced durability
Type Early Models:
5-Speed Manual
Type Later Models And Non-Sti:
4-Speed Automatic (less common on performance models)
AWD System:
Subaru Symmetrical All-Wheel Drive with various center differential types (e.g., viscous coupling, electronically controlled)
Sti Dccd:
Driver Controlled Center Differential (DCCD) on many STI models for adjustable torque distribution
Gear Ratios:
Varies by model and year, detailed in manual
Crash Test Information:
Refer to specific year/model for NHTSA/IIHS ratings; early models may have limited data. Manual will cover SRS airbag system diagnostics.
Braking System:
4-wheel disc brakes, ABS (Anti-lock Braking System) often standard or optional
Traction Control:
Available on later models and specific trims
Airbags:
Driver and passenger front airbags (SRS) standard from early 2000s onwards
Body Structure:
Reinforced chassis for occupant protection
Audio Systems:
Factory head units often featured CD players, AM/FM radio. Later models may have touchscreen displays with navigation options. Manual covers unit removal and wiring.
ABS:
Anti-lock Braking System (ABS) became increasingly common and standard on performance models.
Cruise Control:
Standard on most trims and generations.
ECU Tuning Potential:
These models are popular for ECU tuning to optimize performance. The manual provides baseline information essential for tuners.
Oil Change Interval:
Typically 3,000-7,500 miles (5,000-12,000 km) depending on driving conditions and oil type. Consult manual for exact recommendations.
Timing Belt Replacement:
Recommended every 60,000-105,000 miles (100,000-170,000 km) or 5-7 years, particularly for EJ20/EJ25 engines. Crucial for preventing catastrophic engine failure.
Engine Oil:
API SG/SH/SJ/SL/SM/SN, ILSAC GF-2/GF-3/GF-4/GF-5. Viscosity typically 5W-30 or 10W-30, with synthetic recommended for performance models. Refer to manual for precise specification.
Coolant:
Subaru Super Coolant (blue) or equivalent ethylene glycol-based coolant. Capacity around 7.0-8.0 liters. Consult manual for specific type and procedure.
Transmission Fluid Manual:
API GL-4 or GL-5 gear oil. Specific viscosity (e.g., 75W-90) and capacity (e.g., 1.7-2.0L) detailed in manual.
Transmission Fluid Automatic:
Subaru Genuine ATF HP or equivalent. Capacity around 3.0-4.0L for drain/fill. Consult manual for exact type and capacity.
Brake Fluid:
DOT 3 or DOT 4 brake fluid.
Head Gaskets:
Premature head gasket failure on EJ25 engines (especially non-STI variants) is a well-documented issue. Manual will detail inspection and replacement procedures.
Turbocharger:
Oil starvation or bearing failure on turbochargers can occur due to neglect or poor oil quality. Proper lubrication and maintenance are critical.
Piston Ring Land Cracking:
Can occur on high-mileage EJ25 engines, particularly when subjected to aggressive driving or poor tuning. Manual will provide diagnostic methods.
Clutch Wear:
Clutches in performance models can wear faster with spirited driving. Manual covers clutch inspection and replacement.
Rally Success:
Subaru's extensive WRC (World Rally Championship) success directly influenced the development of the WRX and STI models.
Generations:
GC/GF (1993-2000), GD/GG (2001-2007), GE/GH/GR/GV (2008-2014, partial coverage)
Manufacturing Locations:
Primarily Japan (Gunma Plant)
Performance Variants:
WRX (World Rally eXperimental), STI (Subaru Tecnica International) with enhanced engines, suspension, brakes, and AWD systems.
P1:
Prodrive Performance Package (P1) - a limited edition, performance-focused model often associated with the UK market.
Rally Performance:
Multiple WRC championships and rally stage victories validate the engineering and performance capabilities of the Impreza WRX/STI lineage.
Car And Driver 10 Best:
Various Impreza models, particularly STI variants, have been lauded by automotive publications for their performance and handling.
Homologation:
WRX and STI models were developed for WRC homologation, meaning their design was directly influenced by motorsport requirements.
