What are the differences between three-cylinder and four-cylinder engines?

[Jesse]

There are three main differences between three-cylinder and four-cylinder engines: 1. Three-cylinder engines are smaller and lighter, making them easier to fit into various vehicle models without worrying about space constraints. This is beneficial for overall vehicle space layout and aligns with the lightweight body design concept, whereas four-cylinder engines are slightly heavier. 2. Three-cylinder engines have one fewer cylinder than four-cylinder engines, reducing energy loss due to mechanical wear and improving efficiency. Their compact size and lighter weight also contribute to a smaller overall engine volume and mass. The freed-up space allows for more rational and organized cabin arrangements. Additionally, three-cylinder engines can deliver stronger power output at low torque and help mitigate turbo lag. 3. Even-numbered cylinder engines can balance the reciprocating inertial forces between cylinders, whereas odd-numbered cylinders leave one cylinder in a relatively independent state without a balancing mechanism. Manufacturers have devised various solutions to address this, such as decoupled balance shaft gears, eccentric mass flywheels, and mass-inertia crankshaft pulleys. The vibration-induced wear can accelerate engine lifespan reduction, and the use of flexible belts to reduce vibrations may lower work efficiency. Three-cylinder engines also tend to have poorer high-speed power delivery, with less linear power output. Their power delivery is less smooth, being overly sensitive at low speeds and underpowered at high speeds.