The Achates Power opposed-piston engine is packed full of unique technology. The supercharged, turbocharged, diesel 3 cylinder makes use of six pistons, two of which operate in each cylinder. It's a two-stroke design, meaning every time the pistons come together a power stroke occurs, forcing both pistons away from one another and rotating their respective crankshafts. The two crankshafts are geared together to a common output shaft, which powers the vehicle. Research has shown two-stroke opposed piston engines to be wildly efficient. 3 cylinder designs are the most efficient, and it's possible to achieve brake thermal efficiencies as high as 55%, a massive improvement for road car engines. The engine in this video is a 2.7L 3-cylinder producing 270 HP and 480 lb-ft of torque.