SubaruLegacy20042.5L/subaru/legacy/2004/2-5l/

2004 Subaru Legacy — 2.5L

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 2004 Legacy 2.5L. Covers both the standard and High Output 2.5L.

Body PASSENGER CAREngine 2.5LTransmission Automatic (S4)

The 2004 Subaru Legacy 2.5L is a passenger car powered by a 2.5-liter engine paired with a 4-speed automatic transmission, returning EPA-estimated fuel economy of 18 city, 25 highway, and 21 combined mpg while requiring 4.2 quarts of 5W-30 API-grade oil. In terms of owner-reported issues, this model year accumulated 49 total complaints with Air Bags cited as the most frequent concern, alongside 11 documented recalls. When viewed against the Legacy's complaint history spanning 1990 to 2025—where complaints ranged from a peak of 216 in 1995 to a low of 6 in 2025—the 2004 model sits well below the model's historical average, suggesting relatively fewer widespread problems compared to other model years.

Model year201420132012201120102009200820072004

Quick specs

Fluid capacities, tune-up values and fuel economy at a glance.

Engine oil capacity4.2 qtOEM · verified
Engine oil type5W-30 APIOEM · verified
EPA fuel economy18/25/21 mpgEPA · verified

Fitment & sizes

Replacement part sizes and factory part numbers — battery, bulbs, filters and belts.

From the factory this vehicle uses a BCI 35 · 490 CCA battery. Each part links to every other vehicle that shares it, so a part you already stock may fit more of your fleet than you'd expect.

Battery groupBCI 35 · 490 CCAOEM · verified

Full specifications

Engine, drivetrain, dimensions and economy.

Engine & drivetrain NHTSA vPIC

TransmissionAutomatic (S4)

Dimensions & weight NHTSA vPIC

Overall length184.6 in
Overall width68.9 in
Overall height55.9 in
Wheelbase104.3 in
Curb weight3309 lb
Track (front / rear)57.9 / 57.5 in
Weight distribution (front / rear)54/46

Ratings & economy EPA / vPIC

EPA city / highway / combined18 / 25 / 21 mpg
Drivetrain4-Wheel or All-Wheel Drive
Passenger volume91 cu ft
Cargo volume12 cu ft
Recommended fuelRegular Gasoline

Performance & power Independent road tests

0–60 mph, quarter-mile, horsepower and torque from independent road tests.

No 2004 road test on record; the results below are same-engine tests from nearby model years, each shown under its own year.

8.8–9.1 sec0–60 mph (tested)quickest 8.80 sec — 2003 L
165 hpHorsepower (as tested)
166 lb-ftTorque (as tested)
YearTrim / engine0–60¼ mileHPDrivetrain
2003L 2.5L F-48.80 sec16.80 sec165 hpAWD
20002.5GT Limited 2.5L F-49.10 sec16.60 sec165 hpAWD

Service quick specs OEM factory data

Capacities, torques and tune-up values from the factory service manual.

This engine holds 4.2 qt of 5W-30 API engine oil, DOT 3 brake fluid. Torque the oil drain plug to 33.0 ft-lbs. The firing order is 1-3-4-2. Note the cylinder-head bolts finish on a torque angle (torque-to-yield) — they stretch permanently and should be replaced, not reused, during any head service.

Lubricants & capacities

Automatic Transmission FluidATF
Automatic Transmission Fluid Capacity10.4
Brake FluidDOT 3
Engine CoolantETHYLENE GLYCOL
Engine Oil5W-30 · API
Engine Oil Capacity4.2 qt
Manual Transmission Fluid75W-90 · GL-5
Manual Transmission Fluid Capacity7.0-9.0

Engine torques

Connecting Rod (Large End) Bearings33 ft-lbs
Engine Flywheel Bolts53 ft-lbs
Engine Oil Pan Drain Plug33.0 ft-lbs
Oil Pump to Cylinder BLock Bolts/Studs5 ft-lbs

Chassis torques

Transfer Case Drain Plug17.0-20.0 ft-lbs
Front Wheel Hub162 ft-lbs
Rear Wheel Hub140 ft-lbs

Ignition

Cylinder Firing Order1-3-4-2
Curb Idle Speed (No Load)TURBO: 700 rpm
Curb Idle Speed Variance (No Load)100 rpm
Ignition Coil Secondary Resistance10,880-14,720 ohms
Spark Plug ManufacturerNGK
Spark Plug Torque15.0 ft-lbs
Ignition Timing10 degrees
Ignition Timing Acceptable Variance8 degrees

Battery & A/C

RefrigerantR134a
Refrigerant Capacity0.88-1.65 lbs
Oil GroupPAG
Oil Capacity4.50-5.50 oz
Standard BCI Group Number35
Standard BCI Cranking Performance490 cca

Service checks

Injector Primary Resistance5-20 ohms
Engine Compression156-185 psi
Engine Oil Pressure14 psi @ 600 rpm, 43 psi @ 5000
Intake Valve Lash0.0079-0.0080 in
Exhaust Valve Lash0.010-0.0138 in

Brakes

Brake ApplicationWITH SOLID ROTOR / WITH VENTED ROTOR
Torque to Knuckle58 ft-lbs
Minimum Pad ThicknessFront: 0.295; Rear: 0.256 specification
Brake ApplicationWITH SOLID ROTOR / WITH VENTED ROTOR
Rotor Runout Limit0.0028 in / 0.003 in
Rotor Nominal Thickness From0.39 in / 0.71 in / 0.94 in
Rotor Nominal Thickness To0.39 in / 0.71 in / 0.94 in
Rotor Discard at or Under0.335 in / 0.63 in / 0.87 in

Multi-step torque procedures OEM · verified

Cylinder Head — tightening sequence 8 stages
122 ft. lbs.22 ft. lbs
251 ft. lbs.51 ft. lbs
3Loosen 180 degrees.180 degrees
4Loosen 180 degrees.180 degrees
536 ft. lbs.36 ft. lbs
680-90 degrees..80–90 degrees
740-45 degrees.40–45 degrees
840-45 degrees.40–45 degrees

Factory maintenance schedule OEM · verified

Normal service, condensed from the factory interval matrix.

Under the factory schedule, replace the engine oil and filter at 3,000 mi; coolant every 30,000 mi. The big-interval services (every 30,000 mi for coolant, and the transmission fluid) are the ones owners most often skip — on a lower-mileage example, assume the original fluids are still in it and check them first.

At 3,000 miEngine Oil Filter (replace)
Every 7,500 miEngine Oil Filter (replace) · Tire & Wheel Assembly (inspect)
Every 9,300 miCabin Air Filter (replace)
Every 15,000 miAxle Shaft Oil Seal (inspect) · Brake Line (inspect) · CV Joint Boot (inspect) · Clutch Assembly (inspect) · Parking Brake System (inspect) · Steering System (inspect)
Every 30,000 miBrake Hydraulic System (drain, refill & bleed) · Brake Linings (inspect) · Brake Rotor (inspect) · Differential (inspect fluid level) · Engine Air Filter Element (replace) · Engine Coolant System (leak inspection)
Every 60,000 miWheel Bearing (inspect)
At 105,000 miAccessory Drive Belt (inspect) · Drive Belt (replace) · Timing Belt (replace)

Reliability & federal safety record

Owner-reported issues, recalls, investigations and service bulletins on record with NHTSA — an unfiltered look at what owners actually experience.

The 2004 Legacy records the lowest complaint count (49) of the 2000–2005 window, a notable dip from 2003’s 62 and less than one-third of 2005’s 182, while its 11 recalls sit between 2003’s 15 and 2005’s nine. Technical service bulletins remain high at 193, only marginally below the 2003 peak of 200 and well above the 150 seen in 2002, indicating sustained dealer-level service activity despite fewer owner complaints. Air bag reports dominate the 2004 profile at 24 of 49 complaints, with engine, fuel/propulsion, and speed control issues each in single digits; the data does not specify root causes for any category. Five crash-related complaints were logged with no fire reports. The 2004 model year occupies a relative sweet spot in the generation’s federal record — complaints bottom out before a sharp 2005 surge — but elevated TSB volume and double-digit recalls suggest ongoing manufacturer corrections. For a buyer prioritizing fewer reported owner issues, 2004 is a good year to buy, provided all recall work is verified complete.

11
Open recalls
NHTSA campaigns
193
Service bulletins
Manufacturer communications
2
ODI investigations
Office of Defects Investigation
49
Owner complaints
5 involved a crash · 0 a fire
NHTSA crash-test rating federal NCAP · out of 5 stars
Rollover★★★★

Owner complaints filed with NHTSA, by component

All 49 complaints on record, top 8 components.

Air Bags24
Engine4
Fuel/Propulsion System3
Vehicle Speed Control3
Engine & Engine Cooling2
Power Train2
Suspension1
Air Bags,Unknown Or Other1

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 2 of 11 campaigns on record for this vehicle.

20V003000Air Bags:Frontal:Passenger Side:Inflator ModuleReported 02/01/2020

Subaru of America, Inc. (Subaru) is recalling certain 2009-2013 Forester, 2003-2006 Baja, 2004-2011 Impreza, 2004-2014 WRX (including STI), 2003-2014 Legacy and Outback, and 2005-2006 Saab 9-2X vehicles originally sold… Remedy: Subaru will notify their owners. General Motors will notify Saab owners. Dealers will replace the passenger air bag inflators, free of charge. The recall began January 7, 2020…

20V002000Air Bags:Frontal:Passenger Side:Inflator ModuleReported 02/01/2020

Subaru of America, Inc. (Subaru) is recalling certain 2009-2013 Forester, 2003-2006 Baja, 2004-2011 Impreza, 2004-2014 WRX (including STI), 2003-2014 Legacy and Outback, and 2006 Saab 9-2X vehicles originally sold, or… Remedy: Subaru will notify their owners. General Motors will notify Saab owners. Dealers will replace the passenger air bag inflators, free of charge. The recall began January 7, 2020…

Technical service bulletins NHTSA · verified

Showing 5 of 193 bulletins on record with NHTSA.

BulletinDateComponentSummary
SubaruNet Annoucement (E2026-06-11Unknown Or OtherThis announcement is requesting retailer staff to retain the EyeSight protective hood…
01-167-08R2026-05-18Unknown Or OtherThis bulletin contains additional information for recommended materials listed in the…
SubaruNet Announcement (R2026-05-04Power TrainThis announcement provides information on the remanufactured CVT transmission program.
07-240-26R2026-04-30Unknown Or OtherThis Service Information Bulletin was developed to provide interim guidance for vehicles…
03-97-262026-04-24Power TrainThis bulletin announces the service manual correction regarding clutch master cylinder…

Common OBD-II trouble codes

The most common OBD-II codes for this vehicle's emissions system. These are standardized SAE J2012 definitions, not vehicle-specific fault reports.

P0420
Catalyst system efficiency below threshold — Bank 1
P0300
Random / multiple cylinder misfire detected
P0171
System too lean — Bank 1
P0455
Evaporative emission system leak detected — large leak
P0128
Coolant thermostat below regulating temperature
P0442
Evaporative emission system leak detected — small leak

VIN tools

Decode factory build data for a specific vehicle by VIN.

VIN
Decode a VIN to confirm the transmission and build data for a specific Legacy. OEM
Build data
Plant, GVWR class, engine and body data for any 17-character VIN.
Recalls
Check open recall campaigns against a specific vehicle by VIN.

Vehicles with shared specs

Find every vehicle that shares this one's battery, bulbs, oil capacity, platform or parts.

Reference guides

Cross-vehicle references for the kinds of data on this page.

Frequently asked

How much oil does the 2004 Legacy 2.5L take?

4.2 qt of 5W-30 API SM, per the factory manual.

Does the 2004 Legacy have open recalls?

NHTSA lists 11 recall campaign(s) for this model year. Check your specific vehicle by VIN.

What gas mileage does the 2.5L get?

EPA figures are 18 city / 25 highway / 21 combined mpg.