The advantages of a horizontally opposed engine are as follows: 1. The greatest advantage of a horizontally opposed engine is its low center of gravity. Due to its "flat" cylinder arrangement, it not only lowers the vehicle's center of gravity but also allows for a flatter and lower front-end design, all of which enhance the vehicle's driving stability. 2. At the same time, the horizontally opposed cylinder layout is a symmetrical and stable structure, which makes the engine run smoother than a V-type engine and minimizes power loss during operation. Of course, the lower center of gravity and balanced weight distribution also contribute to better handling. The disadvantages of a horizontally opposed engine are as follows: 1. The horizontally opposed structure is relatively complex, making it difficult to address issues like oil lubrication. Due to gravity, the horizontal cylinders cause oil to flow to the bottom, leaving one side of the cylinders inadequately lubricated. High-precision manufacturing leads to higher maintenance costs, and the wider engine body makes it less favorable for layout. 2. Additionally, because the pistons are placed horizontally and affected by their own gravity, the friction between the top and bottom of the pistons and the cylinder liners during horizontal reciprocation is uneven. This results in different wear patterns on the upper and lower inner surfaces of the cylinder liners, with the bottom experiencing more wear. 3. Furthermore, the idea that horizontally opposed engines can completely cancel out lateral vibrations is an ideal scenario. If valves fail to close fully due to carbon buildup or other reasons, unequal cylinder pressure can occur, leading to unequal lateral forces. In such cases, lateral vibrations can still occur.
