🏷️ Basic Information

Make:

Subaru

Model:

Impreza WRX STI

Year:

2008

Chassis Code:

GR/GV

Engine Code Primary:

EJ257

👋 Introduction

Positioning:

The 2008 Subaru Impreza WRX STI (GR/GV chassis) represents a significant evolution in the iconic performance sedan, offering enhanced handling, a more potent engine, and advanced all-wheel-drive capabilities. This generation is highly sought after by enthusiasts for its rally-bred pedigree and performance tuning potential.

Competitors 2008:

Lancer Evolution, Mitsubishi Eclipse GT, BMW 335i, Audi A4 Quattro.

Performance Focus:

Designed for spirited driving and track performance, featuring Subaru's Symmetrical All-Wheel Drive, Driver-Controlled Center Differential (DCCD), and a turbocharged Boxer engine.

Rally Heritage:

Direct lineage from Subaru's World Rally Championship (WRC) success, translating to robust engineering and exceptional handling dynamics.

📋 Manual Details

Manual Type:

Workshop Service Repair Manual

Language:

English

Format:

PDF

Page Count:

3000+

📖 Manual Coverage

Engine Mechanical:

Detailed disassembly, inspection, and reassembly of EJ257 engine components including block, crankshaft, connecting rods, pistons, cylinder heads, camshafts, valves, and timing system.

Engine Performance:

Turbocharger system (IHI VF43), intercooler, fuel delivery, ignition system, emissions control, and engine control unit (ECU) diagnostics.

Transmission:

6-speed manual transmission (TY856WB1AA) disassembly, inspection, lubrication, and rebuild procedures. Differential maintenance and fluid specifications.

Drivetrain:

All-Wheel Drive (AWD) system, including center differential, front and rear differentials, driveshafts, and axles. Adjustment and maintenance.

Brakes:

Front Brembo 4-piston calipers, rear Brembo 2-piston calipers. Brake fluid specifications, bleeding procedures, rotor and pad replacement, ABS system diagnostics and repair.

Suspension:

MacPherson strut front suspension, multi-link rear suspension. Spring replacement, damper servicing, bushing inspection and replacement, alignment specifications.

Steering:

Power-assisted rack and pinion steering system. Steering fluid, pump inspection, rack and pinion assembly maintenance.

Electrical:

Complete wiring diagrams, fuse box locations, relay functions, battery testing, starter and alternator testing, lighting systems, power windows, central locking, and instrument cluster diagnostics.

Body And Interior:

Exterior body panel removal and installation, door mechanisms, hood and trunk latches, interior trim components, seat removal, dashboard disassembly, HVAC system servicing.

Cooling System:

Radiator, fan control, coolant types, flushing procedures, thermostat replacement, heater core servicing.

Fuel System:

Fuel pump, fuel filter, injectors, fuel pressure regulator, fuel tank servicing, and emissions system (EVAP).

Maintenance:

Scheduled maintenance tasks: oil changes, filter replacements, fluid checks and changes, spark plug replacement, timing belt inspection (if applicable), brake system service.

Troubleshooting:

Diagnostic flowcharts for common drivability issues, electrical faults, starting problems, and performance concerns. Fault code explanations.

Repair:

Step-by-step repair instructions for all major vehicle systems, including engine rebuilds, transmission overhauls, suspension component replacement, brake caliper rebuilds, and electrical component repair.

Diagnostics:

OBD-II diagnostics, scan tool usage, sensor testing, actuator testing, and wiring harness continuity checks.

Specifications:

Torque specifications for all fasteners, fluid capacities and types, engine timing marks, wheel alignment settings, tire pressure recommendations.

Depth:

Comprehensive, covering everything from basic maintenance to complete engine and transmission rebuilds. Includes detailed diagnostic procedures and troubleshooting guides.

📊 Manual Specifications

File Format:

PDF

Searchability:

Searchable text content for quick information retrieval.

Print Quality:

High-resolution images and clear diagrams suitable for printing.

Binding Type:

N/A (Digital PDF)

Paper Type:

N/A (Digital PDF)

⚙️ Engine Specifications

Engine Type:

Horizontally Opposed (Boxer), turbocharged, intercooled, DOHC, 16-valve

Engine Code:

EJ257

Displacement:

2.5 Liters (2457 cc)

Horsepower:

305 hp @ 6000 rpm (US Spec)

Torque:

290 lb-ft @ 4000 rpm (US Spec)

Fuel Delivery:

Multi-point fuel injection (MPI), Electronic Fuel Injection (EFI)

Fuel Type:

Premium Unleaded (91 Octane minimum recommended)

Turbo Model:

IHI VF43

Coolant Capacity:

Approx. 8.1 L (8.6 US qt)

Oil Capacity:

Approx. 5.0 L (5.3 US qt) with filter change

Recommended Oil Viscosity:

5W-30 Synthetic

🔧 Transmission

Transmission Type:

6-speed Manual Transmission

Transmission Model:

TY856WB1AA

Optional Transmission:

N/A (STI models exclusively manual)

Dccd:

Driver-Controlled Center Differential (DCCD) with automatic and manual modes for torque distribution adjustment.

Manual Transmission Fluid Type:

Subaru Extra-S Gear Oil (or equivalent API GL-5, SAE 75W-90)

Front Differential Fluid Type:

Subaru Extra-S Gear Oil (or equivalent API GL-5, SAE 75W-90)

Rear Differential Fluid Type:

Subaru Extra-S Gear Oil (or equivalent API GL-5, SAE 75W-90)

📐 Dimensions

Length:

4415 mm (173.8 in)

Width:

1795 mm (70.7 in)

Height:

1470 mm (57.9 in)

Wheelbase:

2620 mm (103.2 in)

Curb Weight:

Approx. 1540 kg (3395 lbs)

Gross Vehicle Weight Rating:

Approx. 1940 kg (4277 lbs)

Trunk Volume:

Approx. 304 L (10.7 cu ft)

🛡️ Safety Features

NHTSA Front Impact:

5-Star

NHTSA Side Impact:

5-Star

IIHS Front Impact:

Good

AWD:

Subaru Symmetrical All-Wheel Drive System

Stability Control:

Vehicle Dynamics Control (VDC) system

Traction Control:

Traction Control System (TCS)

Airbags:

Front airbags, front side-impact airbags, side curtain airbags.

Seatbelts:

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

💡 Technology Features

Head Unit:

Base models featured a single-CD audio system with 4 or 6 speakers. Optional upgrades included CD changers and premium audio systems.

AWD Control:

Driver-Controlled Center Differential (DCCD) allows drivers to manually adjust front/rear torque split for optimal traction in various conditions.

Instrument Cluster:

Performance-oriented gauge cluster with tachometer, speedometer, boost gauge, and multi-information display.

Bluetooth:

Not standard on all models; available as an option or aftermarket upgrade.

🔧 Maintenance

Oil Change Interval:

Every 3,750 miles or 6 months (severe driving conditions); 7,500 miles or 12 months (normal driving conditions) – check manual for specifics.

Air Filter Replacement:

Every 15,000 miles or 12 months.

Cabin Air Filter Replacement:

Every 15,000 miles or 12 months.

Spark Plug Replacement:

Every 30,000 miles (NGK Iridium recommended).

Brake Fluid Flush:

Every 24 months, regardless of mileage.

Transmission Fluid Change:

Every 30,000 miles (severe use) or as per manual for normal use.

Differential Fluid Change:

Every 30,000 miles (severe use) or as per manual for normal use.

Engine Oil Spec:

API SG, SH, SJ, SL, SM or SN; ILSAC GF-3, GF-4, GF-5; SAE 5W-30 Synthetic

Coolant Type:

Subaru Super Coolant (Blue) or equivalent silicate-free, long-life coolant (50/50 mix with distilled water).

Ring Land Failure:

Known issue on EJ257 engines, particularly with aggressive tuning or sustained high loads, leading to piston ring land damage. Proper maintenance and avoiding excessive detonation are crucial.

Clutch Wear:

High-performance nature of the STI can lead to accelerated clutch wear, especially under spirited driving conditions.

Oil Consumption:

Some EJ257 engines may exhibit higher than average oil consumption, requiring regular checks and top-offs.

📚 Vehicle History

Subaru Rally Legacy:

Subaru's long and successful history in motorsport, particularly the World Rally Championship (WRC), heavily influenced the development and performance characteristics of the WRX STI. Drivers like Colin McRae and Petter Solberg achieved numerous victories driving Subaru Impreza rally cars.

Gd To Gr Transition:

The 2008 model year marked a significant redesign for the Impreza, moving from the second-generation 'GD' chassis to the third-generation 'GR' (hatchback) and 'GV' (sedan) chassis. This generation introduced a larger platform and a new styling direction, including the iconic hatchback variant, while retaining the core performance DNA of the STI.

Production Location:

Japan (Ota, Gunma Prefecture)

Production Years:

2008-2014 (GR/GV Chassis)

🏆 Awards & Recognition

Performance Car Of The Year:

Frequently praised by automotive journalists for its rally-inspired performance and handling capabilities.

Handling Reputation:

Consistently rated highly for its precise steering, balanced chassis, and effective AWD system, making it a favorite among performance driving enthusiasts.