🏷️ Basic Information

Make:

Subaru

Model:

Impreza WRX STI

Year:

2015

Chassis Code:

GVB/GRF (Hatchback), VAB (Sedan)

Engine Code:

EJ257

👋 Introduction

Segment:

Performance Compact Sedan/Hatchback (Performance Variant of Subaru Impreza)

Target Audience:

Enthusiasts, rally fans, performance car owners seeking detailed repair and maintenance information.

Key Competitors:

Mitsubishi Lancer Evolution, Volkswagen Golf GTI, Ford Focus RS, Honda Civic Type R (in spirit and performance class).

Performance Focus:

Built around the iconic EJ257 engine and Symmetrical AWD, the WRX STI offers unparalleled driving dynamics and rally-bred performance.

Brand Heritage:

Direct lineage from Subaru's World Rally Championship (WRC) success, emphasizing performance and all-weather capability.

📋 Manual Details

Primary Coverage:

North America, Europe, Global Markets

Total Pages:

3000+

Type:

Workshop Service Repair Manual

Language:

English

Format:

PDF

📖 Manual Coverage

Engine:

2.5L Turbocharged EJ257 Boxer Engine: diagnostics, overhaul, component testing, cooling system, lubrication system, fuel delivery, ignition system, exhaust system, emissions control.

Transmission:

6-Speed Manual (TY856): gearbox overhaul, clutch system, differential servicing, driveshafts, transfer case, fluid specifications, troubleshooting.

Drivetrain:

Symmetrical All-Wheel Drive (AWD): center differential, front and rear differentials, coupling systems, AWD system operation, servicing, troubleshooting.

Brakes:

Performance Braking System: ABS, EBD, brake calipers, rotors, pads, brake lines, hydraulic system, bleeding procedures, parking brake.

Suspension:

Performance Suspension: struts, springs, anti-roll bars, bushings, wheel alignment specifications, troubleshooting suspension noises.

Steering:

Power Steering System: hydraulic pump, steering rack, tie rods, power steering fluid, troubleshooting leaks and stiffness.

Electrical:

Complete Electrical System: battery, alternator, starter, lighting systems, ECU, sensors, wiring diagrams, diagnostic trouble codes (DTCs), immobilizer system.

Body:

Body & Chassis: exterior panels, doors, hood, trunk, interior trim, glass, corrosion prevention, structural integrity.

HVAC:

Heating, Ventilation, and Air Conditioning: refrigerant system, compressor, condenser, evaporator, climate control unit, troubleshooting.

Safety Systems:

Airbags, seat belts, SRS system diagnostics, pre-tensioners.

Maintenance:

Scheduled maintenance, oil changes, filter replacements, spark plug replacement, belt inspections, fluid level checks.

Diagnostics:

Component testing, fault finding, DTC interpretation, using diagnostic scan tools.

Repair:

Engine overhaul, transmission rebuild, brake caliper replacement, suspension component replacement, electrical component repair.

Troubleshooting:

Step-by-step troubleshooting guides for common and complex issues across all vehicle systems.

Installation:

Replacement of major components and parts.

Depth:

Comprehensive: Covers everything from basic fluid checks and filter changes to complete engine and transmission rebuilds, detailed electrical diagnostics, and bodywork repairs.

📊 Manual Specifications

File Type:

PDF

Quality:

High-resolution, printable pages with clear diagrams and text.

Binding:

Not Applicable (Digital Download)

Paper:

Not Applicable (Digital Download)

Text Search:

Yes, fully searchable PDF for quick information retrieval.

⚙️ Engine Specifications

Engine Type:

Horizontally Opposed (Boxer) Turbocharged DOHC Inline 4-Cylinder

Displacement:

2.5 Liters (2457 cc)

Horsepower:

305 hp @ 6000 rpm

Torque:

290 lb-ft @ 4000 rpm

Fuel Delivery:

Multi-point Fuel Injection (MPI) with Turbocharger

Octane Requirement:

Premium Unleaded (91+ Octane Recommended)

Coolant Type:

Subaru Super Coolant (Blue) or equivalent (50/50 mix with distilled water)

Oil Type:

SAE 5W-30 Synthetic (API SN or ILSAC GF-5 compliant)

Oil Capacity:

4.8 US Quarts (4.5 Liters) with filter

🔧 Transmission

Type:

6-Speed Manual Transmission (TY856)

Type:

None for WRX STI models of this generation

Drivetrain Layout:

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

Manual Transmission Fluid:

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

📐 Dimensions

Length:

Sedan: 180.9 in (4595 mm) / Hatchback: 173.8 in (4415 mm)

Width:

70.7 in (1795 mm)

Height:

58.1 in (1475 mm)

Wheelbase:

104.1 in (2645 mm)

Curb Weight:

Approx. 3373 lbs (1530 kg) for Sedan / 3417 lbs (1550 kg) for Hatchback

Trunk Volume:

Sedan: 11.3 cu ft (320 L) / Hatchback: 19.0 cu ft (538 L) (rear seats up)

🛡️ Safety Features

NHTSA Rating:

Likely 5-Star Overall (based on previous generation and typical Subaru ratings, specific 2015 may vary)

Traction Control:

Standard: Vehicle Dynamics Control (VDC) with Sport Mode.

Braking Assist:

Standard: Anti-lock Braking System (ABS) with Electronic Brake-force Distribution (EBD) and Brake Assist.

Airbags:

Front, Front Side, Curtain, Driver's Knee Airbags.

Seatbelts:

Front 3-point pretensioner, rear 3-point seatbelts.

💡 Technology Features

System:

Standard 6.1-inch touchscreen infotainment system with AM/FM/CD/MP3, SiriusXM Satellite Radio, Bluetooth connectivity, and USB port.

Navigation:

Optional GPS Navigation System.

Camera:

Optional Rearview Camera.

Keyless Entry:

Standard Keyless Entry and Push Button Start.

Bluetooth:

Standard Bluetooth hands-free phone and audio streaming.

🔧 Maintenance

Oil Change Interval:

Every 3,750 miles or 6 months, whichever comes first (severe duty) or 7,500 miles/12 months (normal duty, with synthetic oil).

Engine Air Filter:

Inspect every 7,500 miles, replace as needed or at 15,000 miles.

Spark Plugs:

Iridium-tipped spark plugs: 60,000 miles.

Timing Belt Or Chain:

The EJ257 engine uses a timing belt. Replacement interval is typically 105,000 miles or 105 months, but always consult the manual for precise intervals and related components (tensioner, idlers).

Brake Fluid:

DOT 3 or DOT 4 Brake Fluid

Power Steering Fluid:

Subaru Genuine Power Steering Fluid or equivalent

Clutch Fluid:

DOT 3 or DOT 4 Brake Fluid

Ring Land Failure:

A known potential issue in high-performance EJ257 engines, particularly if subjected to aggressive tuning or inadequate cooling/maintenance. Manual provides diagnostic steps.

Clutch Wear:

Can be accelerated with aggressive driving. Manual covers clutch inspection and replacement.

Differential Issues:

Proper fluid maintenance is crucial for longevity of AWD components. Manual details service procedures.

📚 Vehicle History

Rally Connection:

Subaru's long and successful history in the World Rally Championship (WRC) heavily influenced the development and engineering of the WRX STI.

Generation Start:

The Impreza line began in 1992. The WRX (World Rally eXperimental) and STI (Subaru Tecnica International) variants were introduced shortly after, becoming icons of performance rallying and street performance.

2015 Model Updates:

The 2015 model saw a significant redesign, moving from the previous hatchback-focused platform to a dedicated sedan chassis (VAB) for the STI, while a separate Impreza WRX (without the STI badge) was offered as a hatchback. This generation also saw the introduction of updated engine management and chassis tuning.

Manufacturing Location:

Gunma Plant, Japan

🏆 Awards & Recognition

Performance Awards:

Consistently praised by automotive media for its rally-inspired handling, powerful engine, and AWD capabilities. Often cited as a benchmark in the affordable performance car segment.

Enthusiast Following:

Strong and dedicated enthusiast community, often referred to as 'Subie' owners.