What measurement unit is commonly used for engine displacement?

Engine displacement is a crucial specification that indicates the total volume of all the cylinders in an engine. This measurement reflects the engine's capacity to move air and fuel into the combustion chamber, which directly influences its power output and efficiency.

Cubic inches and liters are standard units used to express this volume. In the United States, engine displacement is commonly measured in cubic inches, while most other parts of the world use liters as the measurement unit. This unit signifies how much space the engine's pistons will displace during their operation, which correlates with the engine's ability to generate power.

The other options are not applicable to engine displacement. Gallons measure liquid capacity, pounds are used to measure weight, and horsepower quantifies engine power rather than volume. Understanding engine displacement is essential for evaluating an engine's performance characteristics and capabilities.