🏷️ Basic Information

Make:

Subaru

Model:

Impreza WRX STI

Year:

2008

Chassis Code:

GR/GH/GE

Market Segment:

Compact Sports Sedan/Hatchback

👋 Introduction

Market Position:

The 2008 Subaru Impreza WRX STI (GR/GH/GE chassis) represented a significant evolution, moving to a more global platform and offering increased performance, refinement, and AWD technology, solidifying its position as a premier rally-bred sports sedan/hatchback.

Competitors:

Competed directly with vehicles like the Mitsubishi Lancer Evolution, Ford Focus RS, Volkswagen Golf GTI, and similar performance-oriented compact vehicles.

Performance Focus:

Renowned for its turbocharged Boxer engine, Symmetrical All-Wheel Drive, and sophisticated suspension tuning, offering exceptional handling and driver engagement.

Rally Heritage:

Directly influenced by Subaru's successful rally racing programs, providing a road-legal performance machine.

Target Audience:

Owners, DIY mechanics, performance tuners, and professional technicians seeking accurate, detailed repair and maintenance information for the 2008 WRX STI.

📋 Manual Details

Covered Models:

All 2008 Subaru Impreza WRX STI models (all trims and engine variants)

Covered Engines:

All engine variants for the 2008 Impreza WRX STI

Estimated Page Count:

Approximately 2000+

Manual Type:

Official Service Manual / Repair Manual

Language:

English

Format:

Digital (PDF)

📖 Manual Coverage

Engine Mechanical:

Engine disassembly, inspection, repair, reassembly, timing belt, cooling system, lubrication system

Engine Performance:

Engine tuning, diagnostics, emissions control systems, turbocharger system

Fuel System:

Fuel injection system, fuel pump, fuel injectors, fuel pressure regulator, evaporative emissions (EVAP) system

Ignition System:

Ignition coils, spark plugs, ignition timing control

Transmission Manual:

Clutch, gearbox, shift linkage, lubrication

Transmission Automatic:

Not applicable for STI models of this generation

Drivetrain AWD:

Symmetrical All-Wheel Drive system, center differential, front differential, rear differential, driveshafts, hub assemblies

Suspension Front:

McPherson struts, control arms, sway bar, bushings, alignment specifications

Suspension Rear:

Multi-link independent suspension, shock absorbers, springs, trailing arms, bushings, alignment specifications

Brakes Front:

Brake calipers (Brembo), brake rotors, brake pads, brake lines, ABS components

Brakes Rear:

Brake calipers (Brembo), brake rotors, brake pads, brake lines, ABS components

Steering:

Power steering system, steering column, tie rods, steering rack

Electrical System:

Battery, charging system (alternator), starting system, fuses, relays, wiring diagrams

Lighting System:

Headlights, taillights, interior lighting, fog lights, bulb replacement

Climate Control:

Air conditioning system, heater core, blower motor, refrigerant, cabin air filter

Body Exterior:

Body panels, doors, hood, trunk lid, bumpers, glass, seals, trim

Body Interior:

Seats, dashboard, door panels, headliner, carpeting, trim panels

Safety Systems:

Airbags, seat belts, SRS system diagnostics

Diagnostic Troubleshooting:

Diagnostic trouble codes (DTCs), troubleshooting flowcharts, component testing

Routine Maintenance:

Oil changes, filter replacements, fluid checks and top-offs, tire rotation, brake inspection

Engine Repair:

Head gasket replacement, piston and ring replacement, crankshaft and bearing service, valve train adjustments

Transmission Repair:

Gearbox overhaul, clutch replacement, differential service

Suspension Repair:

Strut replacement, control arm bushing replacement, wheel bearing replacement, alignment adjustments

Brake Repair:

Brake pad and rotor replacement, caliper service, brake line replacement, brake fluid bleeding

Electrical Diagnostics:

Wiring harness repair, component testing, sensor diagnosis, ECU troubleshooting

Climate Control Service:

AC system recharge, leak detection, heater core replacement

Body Work:

Panel removal and installation, door adjustment, glass replacement

Turbocharger Service:

Turbocharger inspection, repair, and replacement, boost leak testing

Diagnostics And Troubleshooting:

Step-by-step diagnostic procedures for various systems, common fault identification and correction

Technical Depth:

Comprehensive from basic maintenance to complete engine and transmission rebuilds, including electrical system diagnostics and bodywork repairs.

📊 Manual Specifications

File Format:

PDF

Searchable Text:

Yes

Printable:

Yes

Print Quality:

High-resolution, clear diagrams and text

Binding Type:

N/A (Digital)

Paper Type:

N/A (Digital)

⚙️ Engine Specifications

Engine Code:

EJ257

Engine Type:

2.5L (2457cc) DOHC turbocharged horizontally-opposed (Boxer) 4-cylinder

Horsepower:

305 hp @ 6000 rpm (approx.)

Torque:

290 lb-ft @ 3000 rpm (approx.)

Bore X Stroke:

99.5 mm x 79.0 mm

Compression Ratio:

8.2:1

Turbocharger:

IHI VF48 twin-scroll turbocharger with intercooler

Fuel Delivery:

Sequential multi-point fuel injection (MPI)

Fuel Type:

Premium Unleaded (91 octane or higher recommended)

Coolant Capacity:

Approximately 8.5 liters (1.7 US qt)

Oil Capacity:

Approximately 5.8 liters (6.1 US qt) with filter

Oil Type:

API SG or SH, ACEA A2-96 or B2-97, SAE 5W-30 (check manual for specific recommendations)

Timing Belt Interval:

105,000 miles or 105 months (check manual for precise interval and condition)

🔧 Transmission

Transmission Type:

6-speed manual transmission

Transmission Fluid Capacity:

Approximately 2.4 liters (2.5 US qt) for gearbox; 1.1 liters (1.1 US qt) for front differential; 1.0 liters (1.0 US qt) for rear differential (check manual for exact specifications)

Transmission Fluid Type:

GL-4 SAE 75W-90 for gearbox; GL-5 SAE 75W-90 for differentials (check manual for exact specifications)

All Wheel Drive:

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

📐 Dimensions

Length:

4415 mm (173.8 inches) - Sedan; 4465 mm (175.8 inches) - Hatchback

Width:

1795 mm (70.7 inches)

Height:

1450 mm (57.1 inches) - Sedan; 1470 mm (57.9 inches) - Hatchback

Wheelbase:

2620 mm (103.2 inches)

Ground Clearance:

135 mm (5.3 inches)

Curb Weight:

Approximately 1480 kg - 1535 kg (3263 lbs - 3384 lbs) depending on body style and trim

Gross Vehicle Weight Rating:

Refer to vehicle VIN plate

Trunk Volume:

Approx. 12.4 cu ft (Sedan) / 19.0 cu ft (Hatchback, seats up)

🛡️ Safety Features

NHTSA Front Impact:

5-Star (Driver); 4-Star (Passenger) - for 2008 model year Impreza variants

NHTSA Side Impact:

5-Star (Front Occupant); 5-Star (Rear Occupant) - for 2008 model year Impreza variants

IIHS Front Offset:

Good

ABS:

Standard Anti-lock Braking System (ABS)

Traction Control:

Standard Traction Control System (TCS)

Electronic Stability Control:

Standard Vehicle Dynamics Control (VDC) - Subaru's Electronic Stability Control

Airbags:

Standard front airbags, front side-impact airbags, and side-curtain airbags

Seat Belts:

3-point seat belts with pretensioners and load limiters

Child Seat Anchors:

ISOFIX (LATCH) anchoring points

💡 Technology Features

Audio System:

Factory fitted AM/FM/CD audio system, often with auxiliary input. Higher trims may have premium sound systems.

Navigation:

Optional factory navigation system available on some trims.

Cruise Control:

Standard electronic cruise control.

Bluetooth:

Optional factory Bluetooth hands-free system available on some trims.

Dccd:

Driver-Controlled Center Differential (DCCD) allowing manual adjustment of front/rear torque split for enhanced handling and traction control in various conditions.

Si Drive:

Subaru Intelligent Drive (SI-DRIVE) system allowing the driver to select between 'Intelligent', 'Sport', and 'Sport Sharp' modes, altering throttle response, VDC logic, and engine mapping.

🔧 Maintenance

Oil And Filter Change:

Every 3,750 miles or 3 months (severe service); 7,500 miles or 6 months (normal service) - Consult manual for specifics.

Engine Air Filter:

Inspect every 15,000 miles, replace as needed or at 30,000 miles.

Cabin Air Filter:

Inspect every 15,000 miles, replace as needed or at 30,000 miles.

Spark Plugs:

Iridium type: 60,000 miles. Consult manual for exact type and interval.

Brake Fluid:

DOT 3 or DOT 4 (check manual)

Power Steering Fluid:

Subaru Genuine Power Steering Fluid or Dexron III/Mercon ATF (check manual)

Coolant:

Subaru Super Coolant (Blue) or equivalent ethylene glycol-based coolant with corrosion inhibitors (50/50 mix with distilled water)

Head Gaskets:

While the EJ257 is generally robust, early models or improperly maintained examples can be susceptible to head gasket issues. The manual details inspection and replacement procedures.

Oil Consumption:

Some EJ257 engines can exhibit higher oil consumption. Regular checks and top-offs are crucial; the manual covers oil system diagnostics.

Clutch Wear:

Due to the performance nature, the clutch can wear faster with aggressive driving. Manual provides clutch inspection and replacement guidance.

Avcs Issues:

Problems with the Active Valve Control System (AVCS) solenoids or related wiring can occur; the manual offers diagnostic steps.

📚 Vehicle History

Subaru Rally History:

Subaru's decades-long involvement and success in the World Rally Championship (WRC) provided the DNA for the WRX and WRX STI lineage, showcasing engineering prowess in performance and all-wheel-drive technology.

Gd To Gr Transition:

The 2008 model year marked a significant platform change from the GD chassis to the GR/GH/GE chassis, featuring a new body style (including a popular hatchback variant) and refined mechanicals, while retaining the core performance identity.

Wrx Vs Sti Distinction:

The WRX STI version consistently offered enhanced performance features over the standard WRX, including a more powerful engine, upgraded brakes (often Brembo), DCCD, and distinct suspension tuning.

Manufacturing Location:

Japan

🏆 Awards & Recognition

Sport Compact Awards:

The 2008 WRX STI, and the Impreza line in general, often received accolades from automotive publications for their performance, handling, and rally-inspired capabilities.

Reliability Ratings:

Generally considered reliable when properly maintained, though specific model years and engines have documented common service items as detailed in the manual.