EJ25 vs. EJ20: Comparing Subaru’s Popular Engines

EJ25 vs. EJ20: Comparing Subaru’s Popular Engines

EJ25 vs EJ20: Subaru Most Popular Engines Comparison (With Full Specs & Engines for Sale)

Subaru has earned its reputation as a performance and durability heritage due to its legendary boxer engines. Among the most iconic of these are the EJ20 and EJ25—two engines which have powered anything from family sedans to rally-winning STIs and WRXs. If you’re considering swapping, replacing, or simply wish to know which engine is right for your build or daily driver, then look no further than this guide, which will give you everything you’ll need to know.

And if you want to purchase one—purchase us high-spec EJ20 and EJ25 engines with warranty cover and full spec to meet your performance requirements.

Table of Contents

Introduction: Why Compare the EJ20 and EJ25 (EJ25 vs. EJ20)

EJ20 and EJ25 both belong to Subaru’s EJ family of engines, which was launched in 1989 and was the company workhorse for over three decades. The two engines share similar design outlooks but differ in displacement, performance, reliability, and modifiability to fit different purposes.

Whether you’re a tuner looking for a turbocharged beast, a Subaru fanatic rebuilding a JDM classic to its former glory, or just someone who wants to swap a worn-out engine out for a rebuilt or used one that will be reliable, having these two options is essential.

EJ20 vs EJ25: Quick Specs Comparison Table

Specification	EJ20	EJ25
Displacement	2.0L (1994 cc)	2.5L (2457 cc)
Configuration	Flat-4, DOHC	Flat-4, DOHC
Bore x Stroke	92.0 mm × 75.0 mm	99.5 mm × 79.0 mm
Compression Ratio	8.0:1 to 9.0:1 (Turbo)	8.0:1 to 10.0:1 (Turbo/NA)
Horsepower (Stock)	220–280 HP (model dependent)	165–310 HP (model dependent)
Torque (Stock)	210–310 Nm	220–393 Nm
Turbocharged Models	Yes (the majority)	Yes (many); also NA models
Years Produced	1989–2019	1996–present (in some models)
Common Models	WRX, STI, Legacy GT	WRX STI, Forester XT, Outback

Engine Overview: EJ20

Key Features of the EJ20

Displacement: 2.0 liters
Turbocharged & NA Versions
Higher Revving Capability
Loved by JDM Enthusiasts
Smooth Operation & Long Proven History

The EJ20 was Subaru’s initial and longest-running performance engine, most fondly remembered in Japan, Australia, and European markets. With its balanced setup and rev-happy nature, the EJ20 is a performer extraordinaire where responsiveness and engine reliability count the most.

The EJ20 is both tuners’ and performance builders’ darling because of its smooth nature and boost tolerance, especially for JDM STI models.

Popular Cars with the EJ20

Subaru WRX (AUDM and JDM)
Subaru Legacy GT (1990s–early 2000s)
Subaru Forester GT (JDM)
Subaru Impreza STI (Type R/RA, Version I–VI)

EJ20 Specifications by Variant

A few of the most desired variants of the EJ20 engine are:

EJ20G (Early Turbocharged)

Horsepower: ~220–240 HP
Turbocharged
Used in early WRXs and Legacy GTs
Semi-closed deck design

EJ207 (JDM STI Version)

Horsepower: 276–320 HP
Forged internals
High-revving: redline around 8000 RPM
One of the most bulletproof EJ engines

Pros of the EJ20

Strong aftermarket support
Higher redline (up to 8000 RPM)
Rally-honed heritage
Very good fuel economy compared to larger engines

Cons of the EJ20

Less torque than the EJ25
More difficult to find in North America
Need to be revved hard for power

EJ25 Engine Overview

The EJ25’s Most Important Features

Displacement: 2.5 liters
Turbo and Naturally Aspirated Versions
More torque at low RPM
Popular in North America
Very popular in WRX STI (USDM)

The EJ25 is employed more in America and Canada. The EJ25 has higher torque at the lower end compared to the EJ20, thus ideal for everyday driving and heavier vehicles such as the Outback or Legacy GT. It’s also the base of the USDM WRX STI models between 2004 and 2021.

Most Used Vehicles with the EJ25

Subaru WRX STI (USDM)
Subaru Legacy GT (2005–2009)
Subaru Outback XT
Subaru Forester XT
Subaru Impreza 2.5 RS

EJ25 Specs by Model

Some various models of EJ25 engines with specs are:

EJ255

Applied to WRX, Forester XT
Turbocharged, DOHC
Horsepower: 230–265 HP
Semi-closed deck

EJ257 (STI Engine)

Horsepower: 305–310 HP
Turbocharged, forged pistons (certain years)
More aggressive cam profile
AVCS (Active Valve Control System)

Advantages of the EJ25

More torque at low RPMs
Easily available in North America
Suitable for daily use and off-roading
Good aftermarket support

Disadvantages of the EJ25

Some years infamous for head gasket issues
Lower redline than EJ20
Higher fuel consumption

EJ20 vs EJ25: What to Get?

It Depends on Your Application:

Need/Application	Recommended Engine
High-revving performance	EJ20 (EJ207)
More torque for street driving	EJ25 (EJ255/EJ257)
Better availability (US)	EJ25
JDM authenticity	EJ20
Rally-style build	EJ20 or EJ257
Budget swap	Depends on market

We Sell High-Performance EJ20 and EJ25 Engines!

Considering purchasing a used or rebuilt EJ engine? We have:

✅ Used JDM EJ20 Engines (EJ20G, EJ205, EJ207)
✅ Rebuilt EJ25 Engines (EJ255, EJ257)
✅ Turbo & Naturally Aspirated Options
✅ Warranty & Compression Test Engines
✅ Ready-to-Ship in USA & Canada

What Comes With Our Engines:

Long block assembly (block + heads)
Intake manifold (in some packages)
Turbocharger (in some turbo versions)
Wiring harness (optional)
Compression-tested and cleaned
Warranty options available (90-day to 1-year)

Pricing & Availability

Prices are based on condition, variant, and mileage. Here’s a rough idea:

Used EJ20 (JDM): From $1,500
Rebuilt EJ25 (EJ255/257): From $2,200–$3,800
Fully built race-ready EJ25: Inquire for pricing

Installation & Compatibility

If you’re planning a swap or replacement, here are some tips:

EJ25 into WRX/STI: Plug-and-play with minimal mods (if same generation)
EJ20 into GC8/GD chassis: JDM EJ207s are popular for older WRX builds
Wiring and ECU: Some swaps require ECU and harness modification—seek compatibility assistance from us

Modding Potential: What’s Best?

Both the EJ20 and EJ25 engines are modable and can accommodate aftermarket performance pieces, but they will respond differently.

EJ20 for High-Rev, High-Boost Applications

Safer to drive at high revs
Stronger block (especially EJ207)
Less torque but a good option for track cars

EJ25 for Torque-Centric Applications

Better for street everyday driving
More displacement = simpler power gains
Turbo upgrade = instant boost in performance

Reliability: Which Lasts Longer?

EJ20 (especially EJ207):

Typically more reliable high-RPM
Stronger pistons in JDM models
Fewer overheating issues

EJ25:

Certain model years had head gasket issues
Better suited to running under 350 HP unless tuned
Can be highly reliable with proper maintenance

Final Verdict: EJ25 vs EJ20

There is no easy one-size-fits-all, but let’s get a quick summary:

Winner For	Engine
Torque	EJ25
High RPM performance	EJ20
Availability (USDM)	EJ25
JDM Purity	EJ20
Easy Swaps for US Models	EJ25
Long-Term Durability	EJ20 (JDM)

Ready to Buy an EJ Engine?

Rebuilding your STI, restoring a JDM WRX, or just enhancing your daily driver’s performance? We’ve got the EJ20 and EJ25 motors for you—ready to ship.

Get in touch with us today for pricing, availability, or technical support.

✅ Expert assistance
✅ Quality-tested motors
✅ Worldwide shipping
✅ Warranty available

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