What are the drawbacks of a three-cylinder engine?

[Cara]

Here are the disadvantages of a three-cylinder engine: 1. Low power. The reduction in cylinders and intake volume most directly affects power. Additionally, three-cylinder engines are generally small-displacement (1.0-1.5L), and without turbocharging, the power output tends to be weaker. 2. Vibration. Three-cylinder engines have an odd number of cylinders, and while their first and second-order rotational inertial forces and reciprocating forces are balanced, the inertial forces generate corresponding moments that cannot be balanced. This imbalance in first and second-order inertial moments is the source of vibration in odd-cylinder engines. 3. Inconsistent power delivery. In a complete cycle where the crankshaft rotates 720 degrees, only three cylinders perform work, with each cylinder contributing power over 180 degrees of crankshaft rotation. This creates a power gap: when one cylinder finishes its power stroke at the bottom dead center, the crankshaft must rotate an additional 60 degrees before the next cylinder reaches the top dead center to continue the power stroke. As a result, the power output of a three-cylinder engine is intermittent, with a rhythm resembling 1 second of power output, 0.5 seconds of pause, another 1 second of power output, and another 0.5 seconds of pause.

[StLillian]

I've driven quite a few three-cylinder engine cars, and the vibration issues are quite annoying. Especially at idle or low speeds, the steering wheel and seats shake noticeably, making it tiring over long drives. The noise is also louder compared to four-cylinder cars, particularly on highways—it feels like the engine is constantly roaring. Another downside is the uneven power delivery; sudden acceleration brings obvious jerking, making the ride less smooth. Over time, the balance shaft components tend to wear out, leading to higher maintenance costs and complicated part replacements. While manufacturers claim better fuel efficiency, real-world driving often shows higher fuel consumption, especially when using air conditioning or climbing hills. Overall, three-cylinder engines are suitable for city commuting, but they fall short in terms of comfort and performance. I recommend test-driving multiple models before purchasing to avoid regrets.