Why is there water at the back of a car?

[Guzman]

Because when the ambient temperature is relatively low, especially in winter, the car's exhaust pipe will drip water outward, which is actually a very normal phenomenon. Here are the relevant explanations: 1. Complete combustion: When gasoline is completely burned, it produces water and carbon dioxide. At high temperatures, water is in the form of water vapor, which is colorless and transparent. However, when the temperature drops below 100°C, the water vapor condenses into water. If the condensed water droplets are very small and suspended in the air, the water vapor appears as white gas. When the ambient temperature is low, the white smoke from the exhaust pipe is actually water vapor. 2. Water droplet accumulation: If the condensed water droplets accumulate, they turn into water. The water droplets discharged from the exhaust pipe are the result of water vapor generated by the combustion of gasoline condensing in the exhaust pipe and muffler. However, when the ambient temperature is high, the water vapor is discharged before it condenses. When the ambient temperature is low, the water vapor condenses into water droplets on the exhaust pipe wall and is discharged with the exhaust flow.