Engine displacement refers to the total working volume of all cylinders in an internal combustion engine, measured in milliliters (mL). It is a key parameter indicating the engine's size and power potential, calculated based on bore diameter, stroke length, and the number of cylinders. The formula is: Total Displacement = Single Cylinder Displacement × Number of Cylinders Single Cylinder Displacement = π × (Bore Diameter/2)² × Stroke Length (units must be consistent, e.g., millimeters or meters). Displacement directly affects engine torque, power, and fuel efficiency. It is commonly expressed in liters (L), where 1 L = 1000 mL.