What are the differences between three-cylinder and four-cylinder engines in sedans?
2 Answers
The differences between three-cylinder and four-cylinder engines in sedans mainly lie in the following two aspects: 1. Different number of cylinders leads to different balancing forces, with four-cylinder engines generally offering greater stability. The crankshaft and connecting rod piston components of a three-cylinder engine cannot achieve true moment balance, which accelerates wear on the bearing surfaces of the fixed crankshaft. Compared to four-cylinder engines, three-cylinder engines theoretically have a relatively shorter lifespan. 2. The manufacturing structure of three-cylinder turbocharged engines is simpler, with a smaller size and lighter weight compared to four-cylinder engines. The compact size and reduced weight of three-cylinder engines help decrease the overall vehicle weight, save space in the engine compartment, and provide room for electrification components, which is beneficial for the vehicle's spatial layout. Additionally, three-cylinder engines align with the design concept of lightweight vehicle bodies, whereas four-cylinder engines are slightly more cumbersome.
From the perspective of driving dynamics, I've experienced both three-cylinder and four-cylinder sedan engines, and the difference is quite noticeable. The three-cylinder engine is lightweight and agile, providing direct acceleration feel at low RPMs, making it ideal for city commuting; however, it tends to feel underpowered at high speeds or when climbing hills, as if being restrained. In contrast, the four-cylinder engine offers a more balanced and smooth performance, delivering ample power whether starting off or during rapid acceleration, and maintains stable output even at high RPMs. This makes long-distance driving much more effortless. I also noticed that while the three-cylinder engine saves weight due to its simplified structure, it sacrifices smoothness; the additional cylinder in the four-cylinder engine allows for a more even firing sequence, resulting in a silky-smooth driving experience. Under extreme conditions, such as mountain roads or heavy loads, the advantages of the four-cylinder engine become even more pronounced, with prompt power response that provides peace of mind. Overall, if you're after thrilling driving excitement, the four-cylinder is more reliable; but the three-cylinder suits those with limited budgets or for daily short-distance use.
