Page "Reciprocating engine" Paragraph 19

For piston engines, an engine's capacity is the engine displacement, in other words the volume swept by all the pistons of an engine in a single movement.

It is generally measured in litres ( L ) or cubic inches ( c. i. d.

or cu in or in³ ) for larger engines, and cubic centimetres ( abbreviated cc ) for smaller engines.

All else being equal, engines with greater capacities are more powerful and provide greater torque at lower speed ( rpm ) and consumption of fuel increases accordingly, although power and fuel consumption are affected by many factors outside of engine displacement.