The combustion engine operates as any engine in a certain speed range, which is bounded by the idling speed and the maximum speed (revolutions range). The necessary conversion must be carried through a gearbox, since maximum performance and maximum torque are optimally available only in parts of the revolution range.
Thereby, the predominant solution is featured in manual gearbox cars with five or six gears. The five-speed gearbox offers five different gear ratios for the transmission of the engine torque, always proportional to the engine speed and the pull power requirement of the car.
During the transmission, the switching stage must be interrupted for each shift by pressing the clutch of traction between the engine and the powertrain. The six-speed gearbox offers a finer gradation and enables a sports driving style.