Why is the idle speed high in winter?

[Everly]

In winter, the high idle speed occurs because the engine's normal operating water temperature is around 90 degrees Celsius. In extremely low temperatures, after the engine starts, the water temperature sensor sends a signal to the ECU, prompting the engine to increase fuel injection and air intake, thereby raising the engine speed to quickly reach the normal operating temperature. As the engine temperature gradually rises, the idle speed will also gradually decrease to normal levels. The increase in idle speed after a cold start is a normal phenomenon, serving as a protective measure for the engine by the car, and also aimed at improving combustion efficiency and meeting emission standards. The car engine is the device that provides power to the vehicle, acting as the heart of the car, and determines the vehicle's power, fuel economy, stability, and environmental friendliness.