🏷️ Basic Information

Make:

Subaru

Model:

Impreza WRX STI

Model Variant:

WRX STI

Model Year:

2008-2009

Chassis Code Sti:

GRF/GVF

Chassis Code Wrx:

GEF/GEF

👋 Introduction

Segment:

Performance Compact / Rally Sport

Target Audience:

Enthusiasts, performance drivers, rally fans, Subaru performance vehicle owners.

Competitors:

Mitsubishi Lancer Evolution, Volkswagen Golf GTI/R32, Mazdaspeed3, Ford Focus RS

Performance Focus:

Emphasis on turbocharged boxer engines, Symmetrical All-Wheel Drive, and rally-bred handling dynamics.

Manual Value Proposition:

Provides factory-accurate information for maintaining and repairing these specialized performance vehicles, crucial for preserving their integrity and performance.

📋 Manual Details

Coverage:

Complete vehicle service and repair

Estimated Page Count:

Approximately 2000+ pages (typical for factory service manuals of this era)

Type:

Factory Service Manual (FSM) / Workshop Manual

Language:

English

Format:

Digital Download (PDF)

📖 Manual Coverage

Engine:

EJ257 (2.5L Turbocharged DOHC Boxer - STI), EJ255 (2.5L Turbocharged DOHC Boxer - WRX)

Transmission:

6-speed Manual Transmission (STI), 5-speed Manual Transmission (WRX)

Drivetrain:

All-Wheel Drive (Symmetrical AWD), Differential systems (front, center, rear), Axles, Driveshafts

Suspension:

Front MacPherson struts, Rear double wishbone, Springs, Dampers, Bushings, Sway bars, Alignment procedures

Brakes:

Front and rear disc brakes, ABS system, Brake fluid service, Caliper and rotor replacement, Parking brake system

Steering:

Power-assisted rack and pinion, Steering column, U-joints

Electrical:

Battery, Charging system, Starting system, Ignition system, Lighting systems, Fuses, Relays, Wiring diagrams, ECUs, Body Control Module (BCM)

Fuel System:

Fuel pump, Injectors, Fuel pressure regulator, Fuel lines, Evaporative emission control (EVAP)

Cooling System:

Radiator, Water pump, Thermostat, Coolant, Hoses, Fan system

Exhaust System:

Catalytic converter, Mufflers, Exhaust pipes, Oxygen sensors

HVAC:

Air conditioning, Heating, Ventilation, Blower motor, Evaporator, Compressor, Refrigerant service

Body And Trim:

Exterior panels, Doors, Hood, Trunk, Bumpers, Interior trim, Seats, Glass

Safety Systems:

Airbag system, Seatbelts, Pre-tensioners

Maintenance:

Scheduled maintenance, Oil changes, Filter replacements, Fluid checks and changes, Spark plug replacement

Diagnostics:

Troubleshooting guides, Diagnostic trouble codes (DTCs) interpretation, Fault finding procedures

Repair:

Component removal and installation, Engine rebuilds, Transmission overhauls, Suspension component replacement, Brake service, Electrical system repairs

Special Tools:

Identification and usage of Subaru-specific special tools

Torque Specifications:

Detailed torque values for critical fasteners

Wiring Diagrams:

Comprehensive electrical wiring diagrams

Depth:

Comprehensive factory-level diagnostic and repair procedures, suitable for professional technicians and experienced DIY enthusiasts.

📊 Manual Specifications

Format:

PDF

Searchability:

Typically fully searchable text, allowing for quick access to specific topics.

Quality:

High-resolution scanned pages, often replicating the clarity of the original printed manual.

Binding:

Not applicable (digital download)

Paper Type:

Not applicable (digital download)

⚙️ Engine Specifications

Engine Code:

EJ257

Configuration:

2.5-liter turbocharged, DOHC, 16-valve, horizontally opposed (boxer) four-cylinder

Bore X Stroke:

99.5 mm x 79.0 mm

Compression Ratio:

8.4:1

Horsepower Hp:

305 hp @ 6000 rpm

Torque Lb-Ft:

290 lb-ft @ 4000 rpm

Engine Code:

EJ255

Configuration:

2.5-liter turbocharged, DOHC, 16-valve, horizontally opposed (boxer) four-cylinder

Bore X Stroke:

99.5 mm x 79.0 mm

Compression Ratio:

8.4:1 (some variations may exist)

Horsepower Hp:

265 hp @ 6000 rpm (USDM)

Torque Lb-Ft:

247 lb-ft @ 4000 rpm (USDM)

Induction:

Twin-scroll turbocharger (STI), Single-scroll turbocharger (WRX), Top-mount intercooler

Fuel Delivery:

Electronic Multi-Port Fuel Injection (MPI)

Engine Oil Type:

API SG or SH or SJ or SL or SM or SN classification, SAE 5W-30 synthetic or synthetic blend. Check manual for specific viscosity grades for ambient temperatures.

Coolant Type:

Subaru Super Coolant (or equivalent ethylene glycol-based coolant with Subaru anti-corrosion additives)

Piston Ring Land Failure:

A known potential issue in EJ257 engines, particularly with aggressive tuning or sustained high-load operation, leading to oil consumption and compression loss. Manual details proper inspection and potentially updated parts/procedures.

Head Gasket Leaks:

While less common than earlier generations, can occur. Manual covers diagnosis and replacement procedures.

🔧 Transmission

Type:

6-speed Manual Transmission (TY856WB1AA)

Type:

5-speed Manual Transmission (EX195)

Sti AWD System:

Driver Controlled Center Differential (DCCD) with automatic mode for torque distribution.

Wrx AWD System:

Viscous coupling center differential (VCD) with automatic torque distribution.

Sti Transmission Fluid:

API GL-5, SAE 75W-90 synthetic gear oil. Manual specifies Subaru Extra-S or equivalent.

Wrx Transmission Fluid:

API GL-5, SAE 75W-90 synthetic gear oil.

Rear Differential Fluid:

API GL-5, SAE 75W-90 synthetic gear oil.

📐 Dimensions

Length:

4415 mm (173.8 in)

Width:

1795 mm (70.7 in)

Height:

1470 mm (57.9 in)

Wheelbase:

2625 mm (103.3 in)

Length:

4415 mm (173.8 in)

Width:

1795 mm (70.7 in)

Height:

1470 mm (57.9 in)

Wheelbase:

2625 mm (103.3 in)

Trunk Capacity Liters:

Approximately 300-315 L (10.6-11.1 cu ft) depending on specific configuration

Curb Weight Sti:

Approximately 1505 kg (3318 lbs)

Curb Weight Wrx:

Approximately 1475 kg (3252 lbs)

Wheel Bolt Pattern:

5x100 mm

Wheel Size Standard Sti:

18x8.5 inches

Wheel Size Standard Wrx:

17x8.0 inches

Tire Size Standard Sti:

245/40R18

Tire Size Standard Wrx:

225/45R17

🛡️ Safety Features

NHTSA Frontal Crash Driver:

5-Star (for 2008-2009 models)

NHTSA Frontal Crash Passenger:

5-Star (for 2008-2009 models)

NHTSA Side Crash Driver:

5-Star (for 2008-2009 models)

NHTSA Side Crash Passenger:

5-Star (for 2008-2009 models)

NHTSA Rollover Rating:

4-Star (for 2008-2009 models)

ABS:

Standard Anti-lock Braking System

TCS:

Standard Traction Control System

Vsc:

Standard Vehicle Stability Control

Airbags:

Front dual-stage airbags, Front side-impact airbags, Side curtain airbags

Seatbelts:

3-point front and rear seatbelts with pre-tensioners and load limiters

Child Anchors:

LATCH (Lower Anchors and Tethers for Children) system

💡 Technology Features

Audio System:

Standard AM/FM/CD audio system with 4 or 6 speakers. Optional premium audio with subwoofer and satellite radio capability.

Display:

Basic LCD display for audio and climate control. Limited infotainment features compared to modern vehicles.

Cruise Control:

Standard electronic cruise control.

Keyless Entry:

Standard keyless entry system.

Auxiliary Input:

Auxiliary audio input jack usually present.

Bluetooth:

Optional Bluetooth hands-free and audio streaming available on higher trims or as an option.

🔧 Maintenance

Oil Change Interval:

Every 3,750 miles or 6 months, whichever comes first (severe service) or 7,500 miles or 12 months (normal service). Refer to the manual for detailed driving condition definitions.

Air Filter Replacement:

Every 15,000 miles or 12 months.

Cabin Air Filter Replacement:

Every 15,000 miles or 12 months.

Fuel Filter Replacement:

Typically not on a fixed interval, but recommended for inspection or replacement if fuel delivery issues arise. The manual will specify if it's an integrated unit or accessible.

Spark Plug Replacement:

Iridium spark plugs typically require replacement every 60,000 miles.

Brake Fluid Change:

Every 30,000 miles or 36 months.

Coolant Flush:

Every 30,000 miles or 36 months.

Clutch Wear:

Performance driving and repeated aggressive launches can lead to accelerated clutch wear. Manual details clutch inspection and replacement.

Suspension Bushings:

Wear on suspension bushings can lead to noise and imprecise handling. Manual provides replacement procedures for various bushings.

Brake Fluid Type:

DOT 3 or DOT 4

Engine Oil Capacity With Filter:

4.8 US quarts (4.5 liters) for EJ257/EJ255 engines (check manual for exact capacity)

📚 Vehicle History

Rally Roots:

Subaru's long and successful history in the World Rally Championship (WRC) heavily influences the Impreza WRX and WRX STI models, imbuing them with performance DNA.

Generation:

This generation (GE/GH/GR/GV) represents the third generation of the Subaru Impreza, marking a significant departure from the previous sedan-only body style to include a hatchback option. The STI variant typically debuted in hatchback form first.

Design Changes:

Introduced a new chassis and styling, with the hatchback becoming the primary body style for WRX and STI variants in many markets, while a sedan option also became available.

Manufacturing Location:

Japan

Production Years:

2008-2014 (for this generation, with mid-cycle refreshes)

🏆 Awards & Recognition

Car And Driver 10Best:

While not specific to the 2008-2009 models, the Impreza WRX STI has frequently been recognized by automotive publications for its performance and handling capabilities.

Desempeño Manejo:

Consistently praised for its sharp steering, balanced chassis, and potent all-wheel-drive system, often receiving high marks in performance comparisons.