What are the differences between a three-cylinder and a four-cylinder car engine?

[StAlexander]

The differences between a three-cylinder and a four-cylinder car engine lie in their size, weight, and fuel consumption. Below are the explanations of these two differences: Size and Weight Differences: A three-cylinder engine is smaller and lighter, which helps 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 lightweight design philosophy of modern car bodies. In contrast, a four-cylinder engine is slightly bulkier. Fuel Consumption Differences: Due to its structural advantages, a three-cylinder engine excels in fuel efficiency. Its smaller size results in higher power density and improved thermal efficiency. The inherent design of a three-cylinder engine reduces pumping losses, and its smaller cylinder size minimizes friction losses during operation, leading to lower heat dissipation losses and noticeably better fuel economy. On the other hand, a four-cylinder engine, regardless of displacement, has an additional cylinder, which inevitably increases fuel consumption to some extent.