🏷️ Basic Information

Make:

Subaru

Model:

Impreza WRX STI

Model Code:

GDB (Global Design Box - refers to the chassis generation)

Year:

2006-2007

Chassis Code:

GDB-F (for 2006-2007 models, representing the final iteration of this generation)

Engine Code:

EJ257 (for most markets, especially North America)

👋 Introduction

Positioning:

The Subaru Impreza WRX STI of this generation (GD chassis, specifically the 'F' iteration) represented the pinnacle of Subaru's rally-bred performance in a compact sedan package, offering a potent blend of all-wheel-drive grip, turbocharged power, and driver engagement.

Competitors:

Competed directly with performance variants of cars like the Mitsubishi Lancer Evolution, Ford Focus RS, Honda Civic Type R (in spirit, though less AWD), and Volkswagen Golf GTI/R32.

Performance Focus:

Emphasized tarmac and gravel rally performance, symmetrical all-wheel-drive, turbocharged boxer engine, advanced differential systems.

Driver Engagement:

Known for sharp steering, communicative chassis, and a visceral driving experience.

📋 Manual Details

Geographic Coverage:

Primarily North America and global markets for the GDB chassis WRX STI.

Trim Level Coverage:

WRX STI models, including specific variations that may have existed within these years.

Estimated Pages:

1500-2500+ (typical for comprehensive factory service manuals of this era and complexity)

Type:

Factory Service Manual (FSM) / Workshop Manual

Language:

English

Format:

PDF (Digital Download)

📖 Manual Coverage

Engine:

Detailed diagnostics, repair, overhaul, timing belt/chain, lubrication system, cooling system, fuel injection, turbocharger system, emissions control.

Transmission:

Manual transmission (TY856WR1CA, 6-speed), clutch system, driveline, differential (front and rear DCCD system).

Brakes:

Front and rear disc brakes, ABS (Anti-lock Braking System), brake fluid, hydraulic system, parking brake.

Suspension:

Front and rear suspension components, struts, springs, control arms, bushings, sway bars, DCCD (Driver Controlled Center Differential) system integration.

Steering:

Power steering system, steering rack, column, alignment specifications.

Electrical System:

Battery, charging system, starting system, ignition system, lighting, instruments, body electronics, CAN bus communication (limited), diagnostic trouble codes (DTCs).

HVAC:

Heating, ventilation, and air conditioning system diagnosis and repair.

Body And Chassis:

Body panel removal and installation, interior trim, chassis structural information, welding points (if applicable).

Maintenance:

Oil changes, filter replacements, spark plug replacement, fluid checks and changes, brake pad replacement, belt inspection.

Repair:

Engine rebuilds, transmission overhauls, suspension component replacement, brake system repairs, electrical component diagnosis and replacement.

Troubleshooting:

Systematic diagnostic procedures for various symptoms, DTC interpretation and resolution.

Diagnostics:

On-Board Diagnostics (OBD-II) procedures, specific Subaru diagnostic tools and procedures, sensor testing, actuator testing.

Specifications:

Torque specifications for all fasteners, clearances, pressures, voltages, resistances.

Wiring Diagrams:

Comprehensive electrical wiring diagrams for all vehicle systems.

Depth:

Complete workshop level. Covers everything from basic maintenance to full engine and transmission rebuilds, detailed electrical troubleshooting, and body repair.

📊 Manual Specifications

File Type:

PDF

Searchable Text:

Yes (typically, depending on original scanning quality)

Printability:

Printable (intended for user printing)

Binding Recommendation:

Spiral or comb binding recommended for workshop use.

Paper Recommendation:

Heavyweight, durable paper suitable for shop environments.

⚙️ Engine Specifications

Engine Type:

Horizontally-opposed (Boxer) turbocharged 4-cylinder

Engine Code:

EJ257

Displacement:

2.5 Liters (2457 cc)

Bore X Stroke:

99.5 mm x 79.0 mm

Compression Ratio:

8.2:1

Horsepower Usdm:

300 hp @ 6000 rpm (approximate, varies slightly by market)

Torque Usdm:

300 lb-ft @ 4000 rpm (approximate, varies slightly by market)

Fuel Delivery:

Sequential multi-point fuel injection (MPI), Electronic Throttle Control (ETC)

Fuel Type:

Premium Unleaded Gasoline (91 octane or higher recommended)

ECU Type:

Subaru Select Monitor (SSM) compatible ECU

Turbo Model:

IHI VF39 (or VF37 depending on market/specific variant)

Intercooler:

Top-mount air-to-air intercooler

Engine Code Specifics:

EJ257 typically features larger ports and higher flow injectors compared to standard WRX EJ255.

🔧 Transmission

Transmission Type:

6-speed Manual

Transmission Model:

TY856WR1CA (or similar 6-speed variant)

Transmission Type:

N/A (STI models were exclusively manual)

Dccd:

Driver Controlled Center Differential (manual operation via console dial, auto mode available)

Differential Types:

Front: Helical LSD; Rear: Viscous LSD (with DCCD control for center).

Manual Transmission Fluid:

Subaru Genuine Gear Oil API GL-5 75W-90 (or equivalent high-quality synthetic 75W-90)

📐 Dimensions

Wheelbase:

2515 mm (99.0 inches)

Length:

4405 mm (173.4 inches)

Width:

1770 mm (69.7 inches)

Height:

1440 mm (56.7 inches)

Curb Weight:

1505 kg (3318 lbs) (approximate)

Gross Vehicle Weight Rating:

Not explicitly stated, but generally around 1900-2000 kg.

Trunk Capacity:

0.33 m³ (11.7 cu ft) (approximate, varies slightly)

Wheel Size:

17x8.0 inches (standard), 18x8.0 inches (optional/later models)

Bolt Pattern:

5x100 mm

Tire Size Standard:

225/45R17

Tire Size Optional:

225/40R18 or 235/40R18

🛡️ Safety Features

NHTSA Front Crash Rating:

5-star (for driver and passenger, typical for this chassis generation)

IIHS Side Impact Rating:

Good (typically for this chassis generation)

ABS:

Yes, standard with EBD (Electronic Brake-force Distribution)

Traction Control:

Yes, TCS (Traction Control System) and VDC (Vehicle Dynamics Control) standard on STI.

AWD:

Symmetrical All-Wheel Drive with Driver Controlled Center Differential (DCCD)

Airbags:

Driver and front passenger airbags, side curtain airbags available on some trims/markets.

Seatbelts:

3-point front and rear seatbelts with pretensioners and load limiters.

Body Structure:

Reinforced safety cell, crumple zones.

💡 Technology Features

Head Unit:

Factory AM/FM/CD player with basic audio controls. Options for premium sound systems varied by trim.

Display:

Basic LCD display for clock, radio presets, and climate control information. No integrated navigation or advanced smartphone integration.

Cruise Control:

Standard electronic cruise control.

ABS Ebd:

Anti-lock Braking System with Electronic Brake-force Distribution.

Vdc:

Vehicle Dynamics Control (stability and traction control) standard on STI models.

Auxiliary Input:

Optional auxiliary audio input jack for external music players.

Headlights:

Halogen projector headlights, with HID (Xenon) headlights as an option on some trims/markets.

🔧 Maintenance

Oil Change Interval:

Every 3,750 miles (6,000 km) or 3.75 months (especially for spirited driving) using high-quality synthetic oil, or as per owner's manual recommendations.

Engine Oil Filter:

Subaru Genuine Oil Filter 15208AA080 (or equivalent aftermarket)

Spark Plug Replacement:

Typically every 60,000 miles (96,000 km), but recommend checking owner's manual for specific plugs and gaps (e.g., NGK PFR6G-11).

Timing Belt Replacement:

Subaru recommends replacement every 105,000 miles (168,000 km) or 105 months for the EJ257 engine. Essential for this engine to prevent catastrophic damage.

Coolant Replacement:

Subaru Super Coolant (Blue) or equivalent; typically every 30,000 miles (48,000 km) or 2 years.

Brake Fluid Replacement:

DOT 3 or DOT 4 brake fluid; typically every 24 months or 30,000 miles.

Engine Oil Capacity:

5.8 US quarts (5.5 Liters) with filter change.

Engine Oil Viscosity:

0W-30 or 5W-30 Synthetic (refer to manual for specific climate recommendations)

Head Gaskets:

While less prone than earlier EJ series, Subaru head gasket failures can occur. Early detection and proper cooling system maintenance are key.

Piston Ringland Failure:

More common in heavily modified or poorly maintained EJ257 engines. Requires careful attention to engine health, proper fueling, and avoiding detonation.

Clutch Wear:

Due to the nature of the car and potential for spirited driving, clutches can wear prematurely. Clutch fluid should be flushed periodically.

Dccd Failure:

The DCCD system can experience issues, though generally robust. Manual operation should be used periodically if primarily in auto mode.

Catalytic Converter:

Can be prone to failure if engine runs rich or misfires, affecting emissions and performance.

📚 Vehicle History

Rally Roots:

Subaru's extensive history in the World Rally Championship (WRC) directly influenced the Impreza WRX and WRX STI models, making them icons of performance and motorsport heritage.

Generation Gd:

The 2006-2007 models represent the 'GDB-F' iteration of the second generation Impreza (GD chassis), which saw significant styling updates (often referred to as the 'Cosworth' or 'hawk-eye' facelift for the front end) and chassis refinements compared to earlier GD models.

Performance Upgrades 2006 2007:

Wider track, revised suspension geometry, larger brakes, stronger drivetrain components, and the EJ257 engine became standard in most markets.

Production Location:

Gunma Plant, Japan

Production Years Global:

Impreza GD chassis: 2000-2007 (with facelifts and updates throughout)

🏆 Awards & Recognition

Car And Driver 10Best:

While not for the 2006-2007 model specifically, the Impreza WRX STI has a strong history of being recognized for its performance and value in automotive publications.

Motor Trend Car Of The Year:

Subaru has received various accolades, though the STI itself is more focused on specialized performance awards.

Emissions Standards:

Complies with relevant emissions standards for its respective model years and markets (e.g., EPA, CARB in the US).