It's a small milestone for our favorite manufacturer of gold-wheeled, all-wheel-drive sedans and crossovers , as Subaru announced that it has built its 15 millionth Boxer engine – a mere 49 years after it installed a tiny, horizontally opposed, four-cylinder mill in the 1966 1000 sedan.The milestone engine powers something a good bit larger than the 1000, which was (ironically considering Subaru today) the brand's first front-drive vehicle. Today's boxer, the so-called FB25 2.5-liter four, was built for the current Legacy and Outback The 15 millionth Boxer hasn't been the brand's only accomplishment in 2015. The company built its 14 millionth Symmetrical all-wheel-drive system just last month. Subaru has only been at its trademark AWD system for 43 years, and with sales going the way they are , it seems only a matter of time before the Boxer engine is surpassed.