What is the difference between a 3-cylinder and a 4-cylinder car engine?

[SanDylan]

The differences between 3-cylinder and 4-cylinder car engines are as follows: Different in size and weight: The 3-cylinder engine is smaller and lighter, which can reduce the overall vehicle weight. Its compact size also saves space in the engine compartment, providing room for electrification components. This is beneficial for the overall vehicle space layout and aligns with the design concept of lightweight car bodies. In contrast, the 4-cylinder engine is slightly heavier. Different in fuel consumption: Due to its structural advantages, the 3-cylinder engine excels in fuel consumption control. The downsizing of the engine makes it more compact with higher power density and improved thermal efficiency. The structural design of the 3-cylinder engine results in lower pumping losses, and its smaller cylinder size leads to reduced friction losses during operation, along with correspondingly lower heat dissipation losses, resulting in more noticeable fuel economy. On the other hand, regardless of displacement size, the 4-cylinder engine has one more cylinder, which may increase fuel consumption to some extent.