Subaru marks boxer milestone

Subaru is celebrating a major milestone in its history, announcing that it has built its 15 millionth boxer engine.

A mechanical trademark of all the models it sells in Australia, the horizontally-opposed engine configuration is commonly dubbed 'boxer' because of the way the pistons pump horizontally instead of vertically, resembling "the punching action of a boxer", says Subaru.

It could be argued that Subaru continues to punch above its weight division by stubbornly sticking to the unique boxer engine design long after all of its direct rivals opted for more conventional inline or vee engine layouts.

Karl Benz was first to patent the boxer engine, which he called the 'contra' engine in 1896, but it was made famous by Volkswagen with its original 'Beetle' and 'Kombi' models.

Today Porsche is the only other volume car-maker employing boxer engine — presently only six-cylinder petrol form — although BMW Motorrad also uses twin-cylinder boxer engines in its motorcycles.

But Subaru produces more boxer engines in more configurations than anyone else, with 2.0- and 2.5-litre four-cylinder, 3.6-litre six-cylinder, naturally aspirated and turbocharged, and petrol and diesel versions all currently in production.

Subaru states that "the opposing pistons work to cancel out the inertia force of each other, resulting in less vibration, superb rotational balance and a smooth, exhilarating feel, right up to the high rev range".

The first mass-produced boxer engine Subaru produced was a water-cooled four-cylinder aluminium engine fitted to the Subaru 1000 compact passenger vehicle back in 1966, making it almost half a century since it embarked on the unorthodox engine journey.

Perhaps its most iconic boxer engine application is found in the WRX, a vehicle that changed the way Australians viewed four-cylinder performance cars in the 1990s, by delivering a turbocharged wallop combined with all-wheel drive grip, which has become another Subaru hallmark in Australia.

Subaru's 'Symmetrical AWD' system is not far off the boxer's milestone either, with 14 million examples produced since 1972, when the first Subaru vehicle to benefit from AWD was the humble Leone 4WD Estate wagon.

Although it's too early to say if Subaru will launch something special in 2016 to celebrate the boxer's half centenary – perhaps with a bonkers WRX STI or something force-fed fitted to the BRZ – it says it has no plans to end its enduring love affair with either the unique engine configuration or AWD layout.