Subaru is celebrating the 50th anniversary of its horizontally-opposed Boxer engine.

The Japanese carmaker’s very first Boxer engine (the name refers to the punch-counterpunch motion of its pistons) was first introduced on the Subaru 1000 compact passenger car on 14 May 1966.

Ever since then, Subaru has continually improved and enhanced its Boxer engines which continue to power all its vehicles (bar the mini-cars sold in Japan), with total production now topping 16 million units. 

Subaru says that the horizontally-opposed design of the Boxer engine results in “less vibration and superb rotational balance to provide smooth acceleration right up to the highest engine speeds.“ Its compact form also allows it to be fitted lower in the engine bay than a conventional four-in-line engine, thereby lowering the centre of gravity.

The Boxer engine is one of the key components that comprise Subaru’s Symmetrical All-Wheel Drive (AWD) system which delivers superior stability and traction, says Subaru, thanks to the symmetrical layout of the drivetrain allowing a balanced weight distribution, aided by the longitudinally-mounted engine. 

Earlier this year, the Subaru announced the production of its 15 millionth vehicle equipped with the Symmetrical AWD system.