What is the difference between cold start and hot start in cars?

[AngeloAnn]

Car cold start and hot start differences are as follows: Cold start refers to starting the engine when the coolant temperature is low; Hot start means starting the engine when the coolant temperature is high, with the only difference being the temperature of the coolant. Compared to hot start, cold start has the following two disadvantages: 1. Cold start is more harmful to the car: More than 80% of engine wear occurs during the cold start phase. 2. Cold start requires more time to start the vehicle: 1) During cold start, the internal temperature of the engine is too low, making it difficult for the air-fuel mixture to vaporize and combust. 2) During cold start, the engine oil temperature is insufficient, requiring time to increase the oil temperature. 3) During cold start, the gaps between internal engine components are larger, necessitating a warm-up period for thermal expansion to gradually reach the specified clearances, as excessive gaps prevent the oil film from adequately covering and lubricating the parts.