Segment:
Performance Compact / Rally-inspired Sport Sedan
Competitors:
Mitsubishi Lancer Evolution, Ford Focus RS, Volkswagen Golf GTI/R32, Honda Civic Type R
Drivetrain:
Symmetrical All-Wheel Drive (SAWD) system
Engine Layout:
Horizontally-opposed (Boxer) turbocharged engine
Suspension Type:
Independent front and rear suspension, performance-tuned STI suspension components
Braking System:
High-performance Brembo brakes (front and rear)
Target User:
Enthusiast owners, independent repair shops, performance tuners
Engine Mechanical:
Engine disassembly, assembly, component testing, specifications ( EJ257 'Boxer' engine)
Engine Management:
Fuel injection, ignition system, emissions control, ECU diagnostics, sensor data
Transmission:
6-speed manual transmission (TY757) overhaul, clutch system, driveline components
Suspension:
Front and rear suspension components, alignment procedures, shock absorbers, springs, bushings
Brakes:
Brake system diagnostics, hydraulic components, ABS system, rotor/pad replacement, bleeding procedures
Steering:
Power steering system, steering rack, tie rods, alignment specifications
Electrical System:
Wiring diagrams, component testing, battery, alternator, starter, lighting, fuses, relays
Body And Chassis:
Body panel removal/installation, interior trim, glass, doors, frame straightening (if applicable)
HVAC:
Heating, Ventilation, and Air Conditioning system diagnosis and repair
Safety Systems:
Airbag system diagnosis and service, seatbelt mechanisms
Scheduled Maintenance:
Detailed maintenance schedules and procedures
Troubleshooting:
Diagnostic flowcharts and symptom-based troubleshooting guides
Repair And Rebuild:
Step-by-step repair instructions for all major components
Diagnostics:
OBD-II diagnostic trouble codes (DTCs) and related troubleshooting
Torque Specifications:
Comprehensive list of torque specifications for all fasteners
Special Tools:
Identification and usage of Subaru-specific special tools
Depth:
Comprehensive: Covers from basic fluid changes to complete engine and transmission rebuilds
Engine Type:
2.5L turbocharged horizontally-opposed (Boxer) 4-cylinder
Horsepower:
300 hp @ 6000 rpm (SAE Net)
Torque:
290 lb-ft @ 4000 rpm (SAE Net)
Fuel Delivery:
Multi-point sequential fuel injection
Fuel Type:
Unleaded Premium Gasoline (91 Octane or higher recommended)
Bore X Stroke:
99.5 mm x 79.0 mm
Turbocharger Model:
IHI VF39
Engine Oil Capacity:
4.8 US quarts (4.5 Liters) with filter change
Type:
6-speed Manual Transmission
Type:
N/A (STI models exclusively featured manual transmission)
Differentials:
Driver-Controlled Center Differential (DCCD), Helical front LSD, Viscous rear LSD
Manual Transmission Fluid:
API GL-4 or GL-5, SAE 75W-90 (Subaru Extra-S or equivalent recommended)
Manual Transmission Fluid Capacity:
2.3 US quarts (2.2 Liters)
NHTSA Frontal Driver:
5-Star (2006 Model Year)
NHTSA Frontal Passenger:
5-Star (2006 Model Year)
ABS:
4-wheel Anti-lock Braking System (ABS)
Traction Control:
Active All-Wheel Drive with Driver-Controlled Center Differential (DCCD)
Airbags:
Driver and front passenger airbags, front side-impact airbags
Seatbelts:
3-point height-adjustable front seat belts with pretensioners and force limiters, rear 3-point seat belts
Oil Change:
Every 3,750 miles or 3.75 months (severe driving) / 7,500 miles or 7.5 months (normal driving) - consult manual for specifics
Air Filter Replacement:
Every 15,000 miles or 15 months
Spark Plug Replacement:
Every 30,000 miles (iridium type)
Timing Belt:
Not applicable (uses a timing chain)
Coolant:
Subaru Super Coolant (Blue) or equivalent OAT coolant, mixed 50/50 with distilled water
Brake Fluid:
DOT 3 or DOT 4 compatible brake fluid
Power Steering Fluid:
Subaru ATF-HP or equivalent DEXRON-III/MERCON compatible automatic transmission fluid
Head Gaskets:
While less prevalent than earlier EJ engines, potential for coolant leaks exists. Manual details inspection procedures.
Piston Slap:
Some EJ257 engines can exhibit piston slap under cold start conditions. Manual offers diagnostic guidance.
Clutch Wear:
Performance driving can accelerate clutch wear. Manual covers clutch inspection and replacement.
Turbocharger Failure:
Improper maintenance or oil starvation can lead to turbo failure. Manual emphasizes correct oil specifications and change intervals.
Heritage:
Subaru's long-standing reputation for rally racing and all-wheel-drive technology.
Third Generation:
The 2006 model is part of the second iteration of the Impreza WRX STI as a distinct performance model, known for its wider body, more powerful engine, and advanced AWD system.
Manufacturing Location:
Ota City, Gunma Prefecture, Japan
