SUBARU BOXER® Engine: What It Is & How It Works
Key Takeaways:
- The Subaru BOXER® engine uses a horizontally opposed layout that lowers the vehicle’s center of gravity and balances engine movement.
- This flat design improves stability, handling, and smoothness while reducing vibration during driving.
- Subaru uses the BOXER® engine because it pairs naturally with Symmetrical All-Wheel Drive and supports safety, efficiency, and chassis balance.
Built into the DNA of nearly every Subaru vehicle is the powerful SUBARU BOXER® engine, a horizontally opposed engine design. A hallmark of our engineering excellence, the BOXER engine’s unique, balanced design, compact shape, and horizontal layout makes for exceptional handling, smoothness, and stability while driving. Learn more about the SUBARU BOXER engine and how it works.
What is a Boxer Engine?
Sometimes known as a horizontally opposed engine, a boxer engine is a type of engine with cylinders arranged on either side of the crankshaft, facing each other. Its name comes from the way the engine’s pistons move horizontally in a punch-counterpunch rhythm, resembling sparring boxers in a ring.
When it comes to the driving experience, a boxer engine offers a distinct feel on the road. The intentionally low placement of a boxer engine on top of a vehicle’s chassis and even weight distribution create a lower center of gravity compared to other engine types. This enhances a vehicle’s stability, responsiveness, and grip. Drivers may feel the power of the boxer engine as they negotiate sharp turns, conquer challenging terrain, or face inclement weather.
How Does a Boxer Engine Work?
Simplicity is one of the reasons why a boxer engine is so unique and effective, because the opposing layout naturally balances motion. Compared to other common engine types (such as vertically-mounted inline or V-shaped styles), boxer engines are mounted horizontally on the engine. The pistons in a boxer engine face away from each other, with their movement powering the crankshaft and converting to send power to a vehicle’s wheels.
The flat, symmetrical layout of the boxer engine minimizes vibration and friction, allowing for a smoother ride compared to other engine types that involve more complex motion. And with fewer components required to transfer power, boxer engines tend to work more efficiently overall.
Additionally, many SUBARU BOXER engines feature at least four valves per cylinder and dual overhead camshafts, allowing for even more streamlined airflow and optimized performance.
Benefits of the SUBARU BOXER Engine
The boxer engine has directly contributed to the Subaru reputation for reliability and performance. In addition, the SUBARU BOXER engine offers drivers even more advantages:
- Stability and handling: The SUBARU BOXER engine’s horizontally opposed configuration creates a lower center of gravity, optimizing stability while maximizing responsiveness.
- Reduced vibration: Since it operates symmetrically and entirely on one horizontal plane, the SUBARU BOXER engine tends to cause less vibration, resulting in a smoother, more comfortable drive.
- Enhanced safety: Its low mount on a Subaru vehicle’s chassis allows the BOXER engine to drop below the cabin in the event of a frontal collision, rather than forcing it upwards. This design feature helps protect passengers from more serious injury in the event of an accident.
- Improved fuel efficiency: The BOXER engine’s lightweight design and reduced friction make it more fuel-efficient, contributing to greater cost savings over time.
Do All Subaru Vehicles Have Boxer Engines?
All Subaru vehicles with internal combustion engines are equipped with the SUBARU BOXER engine. The only Subaru vehicle that does not feature the boxer engine is the Solterra EV, our first all-electric offering. EVs utilize a different powertrain technology entirely, foregoing a combustion engine in favor of an electric motor. The following Subaru vehicles are equipped with the BOXER engine:
- Subaru Ascent
- Subaru BRZ
- Subaru Crosstrek
- Subaru Forester
- Subaru Impreza
- Subaru Legacy
- Subaru Outback
- Subaru WRX
Why Does Subaru Use Boxer Engines?
Beyond exceptional stability, handling, and efficiency, the boxer engine is an ideal fit for Subaru thanks to the way it powers many of the core systems that are essential to every vehicle we manufacture.
For example, the SUBARU BOXER engine’s symmetrical configuration is the backbone of our Subaru Symmetrical All-Wheel Drive drivetrain system. Placed directly atop the SUBARU BOXER engine, the Symmetrical All-Wheel Drive system delivers variable power to all four wheels thanks to the engine’s compact, balanced design. The impressive power of the SUBARU BOXER engine also supports X-MODE, a useful enhancement to our Symmetrical All-Wheel Drive system featured in many Subaru models.
Experience the balance and performance of the SUBARU BOXER Engine.
Its simple-yet-powerful design makes the SUBARU BOXER engine a key component in many of our vehicles – as well as in our ongoing commitment to safety, outstanding performance, and innovative engineering. Whether you’re commuting to work or cruising towards an off-road weekend adventure, the SUBARU BOXER engine is one of many exciting features designed to offer a smooth ride and outstanding handling wherever your travels take you.
