🏷️ Basic Information

Make:

Subaru

Model:

Impreza WRX STI

Model Variant:

Turbocharged & Naturally Aspirated (Non-Turbo) variants

Generation:

Third Generation (GE/GH/GR/GV)

Chassis Codes:

GR (hatchback), GV (sedan)

Engine Codes Turbo:

EJ257 (2.5L Boxer Turbo)

Engine Codes Non Turbo:

EJ204 (2.0L Boxer NA), EJ253 (2.5L Boxer NA) - *Manual likely covers common non-STI variants equipped in these years

👋 Introduction

Vehicle Class:

Compact Sports Sedan/Hatchback

Performance Segment:

Performance Compact / Rally Homologation Special

Key Competitors:

Mitsubishi Lancer Evolution, Subaru WRX (non-STI variants), Honda Civic Si, Mazdaspeed3

Symmetrical AWD:

Subaru's renowned Symmetrical All-Wheel Drive system with DCCD (Driver Controlled Center Differential) on STI models.

Turbocharged Engine:

Powerful turbocharged Boxer engine for exceptional performance.

Rally Heritage:

Direct lineage from Subaru's successful World Rally Championship cars.

Handling:

Tuned suspension for precise handling and driver feedback.

📋 Manual Details

Years Covered:

2006, 2007

Estimated Page Count:

1500-2500+ (typical for comprehensive factory service manuals)

Manual Type:

Factory Service and Repair Workshop Manual

Language:

English

Format:

Digital (PDF or similar, downloadable)

📖 Manual Coverage

Engine Mechanical:

Engine assembly, disassembly, cylinder head, block, crankshaft, pistons, connecting rods, timing system, lubrication system, cooling system

Engine Management:

Fuel injection system (ECU control, injectors, fuel pump, regulator), ignition system (spark plugs, coils), emissions control system (catalytic converter, EVAP), turbocharger system (operation, wastegate, blow-off valve), intercooler system

Transmission Drivetrain:

6-speed manual transmission (TY856), clutch system, propeller shaft, differentials (front, center DCC - Driver Controlled Center Differential, rear), drive axles, hubs

Brakes:

Front and rear brake systems (calipers, rotors, pads), ABS (Anti-lock Braking System), EBD (Electronic Brakeforce Distribution), parking brake system, brake fluid specifications

Suspension Steering:

Front and rear suspension (struts, springs, control arms, bushings), power steering system (hydraulic pump, rack and pinion), wheel alignment specifications

Electrical Electronics:

Battery, alternator, starter motor, lighting systems (headlights, taillights, interior), fuses and relays, wiring diagrams, ECUs (Engine Control Unit, Transmission Control Unit, Body Control Module), sensors (MAF, MAP, O2, etc.), immobilizer system

Body Chassis:

Body panels, doors, hood, trunk, interior trim, exterior trim, chassis components, subframes, crash structures

HVAC:

Heating, ventilation, and air conditioning system (compressor, evaporator, condenser, refrigerant, cabin filter)

Safety Restraints:

Airbag system, seatbelt systems, pre-tensioners

Routine Maintenance:

Oil changes, filter replacements (oil, air, cabin), spark plug replacement, fluid level checks and top-offs, tire rotation and pressure checks

Engine Repair:

Timing belt/chain service, head gasket replacement, piston ring replacement, valve stem seal replacement, turbocharger rebuild/replacement, fuel injector cleaning/replacement

Transmission Service:

Clutch replacement, transmission fluid change, differential fluid change, manual gearbox rebuild

Brake Service:

Brake pad and rotor replacement, brake caliper overhaul, brake fluid bleeding, ABS component diagnosis and replacement

Suspension Steering Repair:

Shock absorber/strut replacement, bushing replacement, ball joint replacement, tie rod end replacement, power steering pump/rack repair

Electrical Diagnosis:

Troubleshooting electrical faults using wiring diagrams, sensor testing, ECU diagnostics, starter/alternator testing

HVAC Service:

Refrigerant recharging, AC compressor replacement, heater core replacement, blower motor replacement

Bodywork Repair:

Panel replacement, door hinge adjustment, bumper repair, interior trim removal/installation

Troubleshooting:

Diagnostic trouble codes (DTCs), symptom-based troubleshooting guides, common problem diagnosis

Special Tools:

Identification and usage of specialized tools required for specific repairs

Diagnostic Depth:

Comprehensive diagnostic procedures, including data stream analysis and sensor testing with specifications.

Rebuild Procedures:

Detailed step-by-step instructions for complete engine and transmission rebuilds with torque specifications and clearances.

Wiring Diagrams:

Complete, detailed wiring diagrams for all electrical systems, including color codes and connector pinouts.

Torque Specifications:

Extensive list of torque specifications for all critical fasteners throughout the vehicle.

Tolerances Clearances:

Precise specifications for component clearances and tolerances required during engine and transmission rebuilds.

📊 Manual Specifications

File Format:

Searchable PDF

Image Quality:

High-resolution images, diagrams, and schematics

Text Readability:

Clear, legible text for easy reading and reference

Binding Type:

N/A (Digital Download)

Paper Type:

N/A (Digital Download)

Licensing Terms:

Unlimited access, no expiry dates

⚙️ Engine Specifications

Engine Type Sti:

EJ257 - 2.5-liter turbocharged horizontally opposed (Boxer) four-cylinder

Engine Type Non Sti:

EJ204 (2.0L NA), EJ253 (2.5L NA) - common Subaru engines for the era

Horsepower Sti:

305 hp @ 6000 rpm (varies slightly by market/tuning)

Torque Sti:

290 lb-ft @ 4000 rpm (varies slightly by market/tuning)

Horsepower Non Sti:

Approx. 170-175 hp for 2.5L NA, 155 hp for 2.0L NA (typical)

Torque Non Sti:

Approx. 166 lb-ft for 2.5L NA, 145 lb-ft for 2.0L NA (typical)

Fuel Induction:

Multi-point sequential fuel injection (both turbo and non-turbo variants)

Fuel Type:

Premium Unleaded (91 octane or higher recommended for STI)

Pistons Sti:

Forged pistons (STI)

Connecting Rods Sti:

Forged connecting rods (STI)

Coolant Type:

Subaru Super Coolant (Blue) or equivalent silicate-free, long-life coolant

🔧 Transmission

Transmission Type:

6-speed Manual Transmission (TY856) for STI

Gear Ratios Sti:

Specific ratios for each gear (detailed in manual), providing optimal acceleration and highway cruising.

Transmission Type Optional:

5-speed Manual Transmission (for certain non-turbo models)

Transmission Type Automatic:

Not typically available on STI models of this generation; may be available on some non-turbo variants.

Dccd:

Driver Controlled Center Differential (DCCD) with manual and automatic modes for adjustable torque distribution (STI).

Transmission Fluid Type:

GL-5 75W-90 Synthetic gear oil (for manual transmissions) - specific Subaru specs exist.

Differential Fluid Type:

GL-5 75W-90 Synthetic gear oil (front and rear differentials) - specific Subaru specs exist.

📐 Dimensions

Length Hatchback:

Approx. 177.0 inches (4495 mm)

Length Sedan:

Approx. 180.3 inches (4580 mm)

Width:

Approx. 70.1 inches (1780 mm)

Height:

Approx. 57.1 inches (1450 mm) for sedan, 58.5 inches (1485 mm) for hatchback

Wheelbase:

Approx. 103.2 inches (2620 mm)

Curb Weight Sti:

Approx. 3373 lbs (1530 kg) for sedan, 3417 lbs (1550 kg) for hatchback

Gross Vehicle Weight Rating:

Refer to vehicle specific VIN plate.

Cargo Volume Hatchback:

Approx. 19.0 cubic feet (seats up)

Cargo Volume Sedan:

Approx. 11.6 cubic feet

Wheel Bolt Pattern:

5x100mm

Tire Size Sti:

225/45R18 (standard)

Wheel Size Sti:

18x8.5 inches (standard)

🛡️ Safety Features

NHTSA Ratings:

Varies by specific test year and configuration. Frontal impact often rated highly. Side impact and rollover ratings should be checked for specific model year.

ABS:

Standard Anti-lock Braking System

Ebd:

Standard Electronic Brakeforce Distribution

Traction Control:

Standard Traction Control System (TCS)

Stability Control:

Standard Electronic Stability Control (VDC - Vehicle Dynamics Control)

Airbags:

Driver and front passenger airbags, front side-impact airbags, side curtain airbags (often standard on STI).

Seatbelts:

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

Child Seat Anchors:

LATCH (Lower Anchors and Tethers for Children) system

💡 Technology Features

Audio System:

Standard AM/FM/CD stereo system with optional premium audio, auxiliary input, and potentially satellite radio.

Navigation:

Optional factory navigation system available on higher trims.

Cruise Control:

Standard cruise control.

Bluetooth:

May be available as an option or aftermarket integration, less common as standard for this era.

Instrument Cluster:

Performance-oriented instrument cluster with tachometer, speedometer, fuel, temperature gauges, and multi-information display.

Engine Monitoring:

On-board diagnostics (OBD-II) system for engine monitoring and fault code retrieval.

🔧 Maintenance

Oil Change Interval:

Every 3,750 miles or 6 months for severe driving, or 7,500 miles/12 months for normal driving (consult manual for specifics).

Air Filter Replacement:

Every 15,000 miles or 12 months, or as needed based on conditions.

Cabin Air Filter Replacement:

Every 15,000 miles or 12 months.

Spark Plug Replacement Sti:

Around 60,000 miles for iridium-tipped spark plugs (check manual for exact spec and type).

Timing Belt Replacement:

This generation uses a timing chain on most engines, but the manual will detail any specific maintenance requirements for the timing system.

Engine Oil Specification:

0W-30 or 5W-30 Synthetic engine oil meeting API SN/SM or ILSAC GF-5 standards (check manual for specific viscosity and API requirements).

Engine Oil Capacity Sti:

Approx. 5.5 quarts (5.2 liters) with filter change.

Brake Fluid Specification:

DOT 3 or DOT 4 brake fluid (ensure meeting relevant standards).

Power Steering Fluid Specification:

ATF Dexron II/III or Subaru Genuine Power Steering Fluid.

Engine Internal Wear:

Piston ring land wear in some EJ257 engines, leading to oil consumption and potential ringland failure if not addressed. Regular oil checks are crucial.

Clutch Wear:

Clutch wear can be accelerated by aggressive driving, as expected for a performance vehicle.

Suspension Bushings:

Wear in suspension bushings can lead to vague handling and noise over time.

Turbocharger Reliability:

While robust, the turbocharger requires proper maintenance (regular oil changes, avoiding heat soak) for longevity.

📚 Vehicle History

Brand Focus:

Subaru is known for its horizontally-opposed ('boxer') engines and Symmetrical All-Wheel Drive systems, often associated with rally racing and outdoor lifestyles.

Impreza Lineage:

The Impreza line was introduced in 1992 as Subaru's compact car, with the high-performance STI (Subaru Tecnica International) variant debuting shortly after, gaining significant global recognition through WRC victories.

Third Generation Intro:

The third generation (GE/GH/GR/GV) debuted for the 2007 model year in the US, marking a significant redesign with the introduction of a hatchback body style alongside the sedan.

Manufacturing Location:

Japan (Gunma Prefecture)

Production Period For Manual:

2006-2007 model years

🏆 Awards & Recognition

Automotive Journal Awards:

The Subaru Impreza WRX STI has consistently received accolades from automotive publications for its performance, handling, and rally-inspired capabilities.

Performance Car Awards:

Often featured in 'best performance car' or 'best affordable sports car' lists by various automotive media.

Track Day Capabilities:

Highly regarded for its track day performance and tuning potential.