A 3-cylinder engine is a compact internal combustion engine commonly used in cars, motorcycles, and industrial applications, offering a balance of power and efficiency. In SolidWorks, it is designed using Extrude, Revolve, and Assembly features to model the cylinders, pistons, crankshaft, and valve mechanisms, with motion and flow simulations to analyze performance. Typically made from aluminum or cast iron, it enhances fuel efficiency, reduces emissions, and provides a lightweight alternative for vehicles while maintaining sufficient power output.