What's the Difference Between a Three-Cylinder and a Four-Cylinder Sedan?

[LeEdward]

The main differences between a three-cylinder and a four-cylinder car are as follows: 1. Different number of cylinders. Since a three-cylinder engine has one less cylinder than a four-cylinder engine, its size is generally more compact. 2. Turbocharging differs. Four-cylinder engines are more commonly naturally aspirated, whereas modern three-cylinder engines are almost always turbocharged to compensate for their smaller displacement and weaker power output. Therefore, aside from the number of cylinders and displacement, the presence of a turbocharger can also be considered a distinguishing factor between three- and four-cylinder engines. 3. Balance shafts vary. The crankshaft connecting rod mechanism in an engine exerts complex variable forces on the crankshaft during operation, causing engine vibration, which is unrelated to the number of cylinders. However, inline four-cylinder engines inherently suppress this vibration to some extent because cylinders 1 and 4, as well as 2 and 3, move in pairs (up and down together). Hence, even Mercedes-Benz's four-cylinder engines incorporate balance shafts for further refinement.