Subaru's Boxer Engine Celebrates Its 50th Birthday

Jason Siu
by Jason Siu
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subaru s boxer engine celebrates its 50th birthday

The Subaru Boxer engine is celebrating its 50th anniversary this year.

Originally introduced on May 14, 1966 in the Subaru 1000 compact passenger car, the Japanese automaker has since produced more than 16 million units. Today, every vehicle sold by Subaru is powered by a Boxer engine, which features a horizontally opposed design with the pistons facing each other in a side-by-side symmetrical layout.

With the opposing pistons working to cancel out the inertia force of each other, the engine has less vibration and superb rotational balance to provide a smooth feel through the rpm band.

SEE ALSO: 2017 Subaru Outback Touring, Legacy Sport Introduced

Subaru considers its iconic Boxer engine to be one of the key components in the company’s distinctive Symmetrical All-Wheel Drive (AWD) system. The symmetrically laid-out drivetrain helps provide balanced distribution of weight, so that the AWD system delivers excellent performance and stability at high speeds.

The Japanese automaker isn’t the only company that uses a horizontally opposed engine design. Porsche is also famous for having flat-four and flat-six engines in its lineup. The German automaker, however, doesn’t offer it on every vehicle in its lineup – something that Subaru does.

Celebrating the 50th Anniversary of the Subaru Horizontally-Opposed “Boxer” Engine.

— Subaru (@subaru_usa) May 10, 2016

Discuss this story on our Subaru WRX Forum

Jason Siu
Jason Siu

Jason Siu began his career in automotive journalism in 2003 with Modified Magazine, a property previously held by VerticalScope. As the West Coast Editor, he played a pivotal role while also extending his expertise to Modified Luxury & Exotics and Modified Mustangs. Beyond his editorial work, Jason authored two notable Cartech books. His tenure at saw him immersed in the daily news cycle, yet his passion for hands-on evaluation led him to focus on testing and product reviews, offering well-rounded recommendations to AutoGuide readers. Currently, as the Content Director for VerticalScope, Jason spearheads the content strategy for an array of online publications, a role that has him at the helm of ensuring quality and consistency across the board.

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4 of 5 comments
  • Craig Cole Craig Cole on May 11, 2016

    Too bad Subaru's engines grumble like a piece of agricultural equipment. Also, I don't find them to be particularly smooth despite their supposed internal balance.

    • See 1 previous
    • Brian Murray Brian Murray on May 20, 2016

      I seem to be in the minority here, but an Impreza WRX STi is on my personal top 5 best sounding sports cars list. I have a 2003 Outback and I love the way it sounds when it gets wound up.

  • Haefen Haefen on May 11, 2016

    IMO the horizontally opposed design makes perfect sense for an aircraft when you have to look over the engine or a sports car when you are trying to keep a low profile and low center of mass but they do not make as much sense in an SUV or crossover which is the bulk of their sales in some markets. When the pistons are lying flat in the cylinder there is uneven wear on the rings and cylinder on start up. This wear is concentrated on the lower side of the piston because of the weight of the components and can result in piston slap while warming up which is sometime heard in older Suby's. Aircraft are normally started and run continuously so that wear is minor but a city car will have many more starts resulting in more wear. Then there is the restricted access to the engine. An aircraft has no such restriction but in a car using a horizontally opposed design almost always means having to remove the engine to do checks or maintenance and repairs which increases costs over other designs. Other designs allow even cylinder head removal to be done with engine in place and without having to remove and install hundreds of bolts. But 50yrs show those negatives do not outweigh the positives which include one of the cheapest and most effective AWD designs. Hopefully their electric drive system will be as successful.