🏷️ Basic Information

Make:

Subaru

Model:

Impreza WRX STI

Year:

2008

Chassis Code:

GR (Hatchback), GE (Sedan)

👋 Introduction

Market Position:

The 2008 Impreza WRX STI represented Subaru's flagship performance compact, positioned as a highly capable, rally-bred homologation special with a focus on all-wheel-drive traction and turbocharged power, competing against models like the Mitsubishi Lancer Evolution.

Competitive Analysis:

Competed directly with the Mitsubishi Lancer Evolution IX/X, Ford Focus RS, Volkswagen Golf GTI (though often positioned higher than the GTI), and other performance-oriented sport compacts. Its symmetrical all-wheel-drive system and driver-focused cockpit were key differentiators.

Key Features:

Legendary Subaru Symmetrical All-Wheel Drive, potent EJ257 turbocharged boxer engine, DCCD (Driver Controlled Centre Differential), Brembo brakes, sport-tuned suspension, aggressive styling, limited-slip front and rear differentials.

📋 Manual Details

Coverage Areas:

Complete service and repair for 2008 Subaru Impreza WRX STI models (GR/GE chassis variants).

Page Count:

Estimated 2000+ pages (typical for comprehensive dealer service manuals).

Manual Type:

Factory Service Manual (FSM) / Repair Manual

Language:

English

Format:

PDF

📖 Manual Coverage

Systems Covered:

Engine, Drivetrain (AWD System, Differentials, Transmission), Suspension, Steering, Brakes, Electrical System, HVAC, Body, Interior, Fuel System, Exhaust System, Cooling System, Lubrication System, Emission Control Systems.

Procedures Included:

Diagnostic procedures, troubleshooting guides, component removal and installation, repair and overhaul instructions, tightening specifications, wiring diagrams, component testing, maintenance procedures, alignment specifications.

Technical Depth:

Comprehensive, covering everything from routine maintenance and inspections to complete engine and transmission rebuilds, complex electrical diagnostics, and bodywork repairs. Suitable for professional technicians and advanced DIY enthusiasts.

📊 Manual Specifications

File Format:

Searchable PDF with hyperlinked table of contents and cross-references.

Print Quality:

High-resolution scans of original factory documentation, ensuring clarity of text and diagrams.

Binding Type:

N/A (Digital PDF format)

Paper Type:

N/A (Digital PDF format)

⚙️ Engine Specifications

Primary Engine:

2.5L EJ257 Flat-4 (Turbocharged Boxer)

Horsepower:

305 hp @ 6000 rpm

Torque:

290 lb-ft @ 3500 rpm

Fuel System:

Sequential Multi-Port Fuel Injection (MPI), Electronic Throttle Control

Engine Management:

ECU: Subaru Engine Control Module (ECM), ignition system: Coil-on-plug ignition

Block Material:

Aluminum Alloy

Head Material:

Aluminum Alloy

Bore X Stroke:

99.5 mm x 79.0 mm

Compression Ratio:

8.4:1

Turbocharger:

IHI VF48 Twin-Scroll Turbocharger with Intercooler

🔧 Transmission

Transmission Type:

6-speed Manual Transmission

Transmission Type:

N/A (Only Manual Available for WRX STI)

Dccd:

Driver Controlled Centre Differential (DCCD) with automatic mode and manual bias control.

Drivetrain Layout:

Symmetrical All-Wheel Drive (AWD)

Differentials:

Front: Helical Limited-Slip Differential (LSD), Rear: Viscount Limited-Slip Differential (LSD)

Clutch Type:

Hydraulic Actuated, Single Dry Plate Clutch

📐 Dimensions

Length:

GR Hatchback: 173.8 in (4415 mm) / GE Sedan: 180.3 in (4580 mm)

Width:

GR Hatchback: 70.1 in (1780 mm) / GE Sedan: 70.1 in (1780 mm)

Height:

GR Hatchback: 58.1 in (1475 mm) / GE Sedan: 57.0 in (1450 mm)

Wheelbase:

103.0 in (2615 mm)

Cargo Volume Hatchback:

Approx. 19.6 cu ft (rear seats up)

Curb Weight:

Approx. 3350-3400 lbs (1520-1540 kg)

Wheel Size:

18 x 8.5 inches

Bolt Pattern:

5x114.3 mm (5x4.5 inches)

Offset:

ET 55

Tire Size:

225/40R18 (standard fitment)

🛡️ Safety Features

NHTSA Front Crash Test:

5-Star (Driver and Passenger)

NHTSA Side Impact Test:

5-Star (Front and Rear Seat Passengers)

IIHS Front Crash Rating:

Good

Active Features:

Subaru Symmetrical All-Wheel Drive, ABS with Electronic Brake-force Distribution (EBD), Brake Assist, Traction Control System (TCS), Vehicle Dynamics Control (VDC).

Passive Features:

Front dual-stage airbags, front side-impact airbags, side curtain airbags (hatchback), front seatbelt pretensioners with force limiters, collapsible steering column.

💡 Technology Features

Infotainment System:

Base model featured a standard CD player with auxiliary input. Optional upgraded stereo systems were available.

Driver Assistance:

ABS, EBD, Brake Assist, Traction Control System (TCS), Vehicle Dynamics Control (VDC).

Connectivity:

Standard AUX input for audio devices. Bluetooth connectivity was not standard on most 2008 STI models.

Performance Tech:

SI-DRIVE (Subaru Intelligent Drive) system allowing driver selection of engine and drivetrain response modes (Intelligent, Sport, Sport Sharp). DCCD for center differential bias adjustment.

🔧 Maintenance

Oil Change Interval:

Every 3,750 miles (6,000 km) or 3 months (severe service) / 7,500 miles (12,000 km) or 6 months (normal service).

Spark Plug Replacement:

Every 30,000 miles (48,000 km) for iridium-tipped spark plugs.

Timing Belt Replacement:

Every 105,000 miles (168,000 km) or 7 years, whichever comes first (for vehicles with timing belts). Note: The EJ257 in the 2008 STI uses a timing belt.

Engine Oil Type:

SAE 5W-30 (API SN or higher, ILSAC GF-5 or higher). Synthetic oil recommended.

Engine Oil Capacity:

5.5 US quarts (5.2 liters) with filter change.

Coolant Type:

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

Transmission Fluid Type:

Manual Transmission: Subaru Genuine Manual Transmission Oil (75W-90 GL-5) or equivalent.

Differential Fluid Type:

Front/Rear Differential: Subaru Genuine Differential Oil (75W-90 GL-5) or equivalent.

Brake Fluid Type:

DOT 3 or DOT 4.

Known Issues:

Ring land failures in EJ257 engines (often due to detonation or poor tuning), clutch wear (performance driving), turbocharger oil feed line issues, oil consumption, rear differential pinion seal leaks.

Oil Filter Part Number:

Subaru: 15208AA12A or aftermarket equivalent (e.g., Wix 57712, K&N HP-3001).

Engine Air Filter Part Number:

Subaru: 16546AA12A or aftermarket equivalent.

📚 Vehicle History

Brand Heritage:

Subaru's heritage is deeply rooted in motorsport, particularly rallying, with the Impreza WRX and WRX STI models being direct descendants of Subaru's World Rally Championship (WRC) winning cars. This lineage imbues the STI with a performance DNA.

Model Evolution:

The 2008 model year marked a significant redesign for the Impreza, moving to the third generation (GR/GE chassis). The WRX STI variant received a more powerful engine and advanced suspension and drivetrain technologies, including the DCCD.

Production Years:

2008-2014 (GR/GE generation)

Production Location:

Gunma Prefecture, Japan

🏆 Awards & Recognition

Recognitions:

While specific awards for the 2008 model year are less documented, the Impreza WRX STI lineage consistently received praise for its performance, handling, and rally-bred capabilities from automotive publications globally.