What is a Horizontally Opposed Engine?
2 Answers
Horizontally opposed engine refers to an engine where the pistons are evenly distributed on both sides of the crankshaft and move horizontally left and right. The horizontally opposed engine reduces the overall height and length of the engine, lowers the center of gravity of the vehicle, making the driving more stable. The engine is installed on the central axis of the vehicle, and the torque generated by the pistons on both sides cancels each other out, greatly reducing the vibration during driving, allowing the engine speed to be significantly increased and noise to be reduced. The horizontally opposed engine is also known as an H-type engine and is a type of V-engine. Vehicles equipped with horizontally opposed engines include Subaru and Porsche.
The horizontally opposed engine is a special engine design where the pistons are arranged in pairs horizontally, moving in opposition to each other, much like two hands clapping. This layout lowers the vehicle's center of gravity, providing greater stability during turns or high-speed driving, with improved handling and less tendency to shake compared to traditional vertical engines. I’ve personally experienced this while driving a Subaru, especially on mountainous roads—it feels incredibly stable, with minimal vibrations, making long drives less fatiguing. The downside is its complex design, requiring specialized tools for maintenance, which can increase costs. However, the overall driving experience is highly rewarding. Its origins trace back to early aircraft engines, and today it’s widely used in models like the Porsche 911 and Subaru, seamlessly pairing with all-wheel-drive systems to enhance overall performance. While fuel consumption may be slightly higher, its efficiency and balance are certainly commendable.
