The term cylinder capacity, applied to the engine of a car, designates the volume, that is to say the space that results when the piston moves in a cylinder from top to bottom. Through this working movement of the piston stroke, the piston cross-section area is also effectively interested. Cylinder capacity defines, thus, the volume, which is displaced through the displacement of the total of all the pistons (total cylinder capacity). The volume displacement V is thus generated out of the effective piston area Aw and the displacement path h. The result is the formula: V = Aw*h. The cubic centimetre or the litre is mostly employed as the reference unit of measurement.
A combustion engine burns a mix of fuel and gas. To achieve this, the fuel gets ignited in the cylinders. Through the combustion, gases are formed, which, owing to the temperature, propagate. The ensuing pressure affects the cylinders, and causes them to get displaced. This up and down movement of the cylinders is known as “displacement”. Through a crank mechanism, this displacement is transformed in a rotation movement, which in turn powers the engine. In otherwise equal conditions, the cylinder capacity of a motor vehicle is an indicator that serves to compare its performance, and, therefore, an important parameter of assessment of combustion engines. By increasing the number of cylinders, and with them, the cylinder capacity, a car’s performance can be improved.