What is the difference between cold start and hot start of a car?

[Jan]

Here are the specific differences between cold start and hot start of a car: 1. Starting method: Cold start refers to starting the engine after it has been shut down for a period of time, when the engine has cooled down and its temperature is much lower than the normal operating temperature, and the engine oil has basically flowed back. Generally, the ambient temperature can be used as a reference. After the engine is shut down, it slowly cools to below 40°C, usually taking about 2 hours, and starting it at this time is considered a cold start. Hot start means starting the engine when it has just been shut down and the engine temperature is still near the normal operating temperature, with the engine oil on the friction surfaces not yet flowed back and the oil film still present. 2. Impact on the car: Cold start is more damaging to the car compared to hot start, with over 80% of engine wear occurring during the cold start phase. Cold start is also more difficult and takes longer to start the car compared to hot start.