When I will say Boxer engine you will definitely think to Subaru. These days, the Japanese car manufacturer is celebrating 50 years of boxer engines. The first model that got the horizontally-opposed combustion engine was the Subaru 1000.
The model was launched in May 14, 1966. After 50 years Subaru has managed to offer this impressive Boxer engine in every vehicle (except some mini cars designed for Japan). Its total production over the past five decades tops 16 million Boxer units.
Do you know why they have called it Boxer? Because of the engine’s pistons movement. The side-to-side symmetrical layout resembles the movement of a boxer’s fists. Another important fact is that the piston’s movement are canceling the inertia force of each other. As a result they have less vibration and a great rotational balance.
Source: Subaru