Joutokäynnin

Joutokäynnin, often translated as "idle running" or "idling," refers to the operation of an engine, typically a combustion engine in a vehicle, when it is running but not engaged in propelling the vehicle. This occurs when the engine is switched on but the transmission is in neutral or park. In this state, the engine continues to burn fuel, generating exhaust gases, but its power is not being used to move the vehicle forward or backward.

Idling is a necessary state for many vehicles, allowing for systems like the air conditioning, heating, or radio to operate without the engine being under load. It also permits the driver to wait for periods, such as at a traffic light or when picking up or dropping off passengers, without shutting down and restarting the engine.

However, prolonged idling can be inefficient, consuming fuel without achieving any productive purpose. This leads to increased fuel costs and unnecessary emissions, contributing to air pollution and greenhouse gas effects. Many modern vehicles incorporate features like automatic start-stop systems to mitigate the effects of idling, shutting down the engine after a short period of inactivity and restarting it when needed. In some regions, regulations or recommendations exist to limit unnecessary idling to promote fuel conservation and environmental protection.