What Causes White Smoke from Car Exhaust in Winter?
1 Answers
In winter, the reason why car exhaust continuously produces white smoke is that the exhaust gas coming out of the tailpipe is at a high temperature. The high-temperature water vapor rapidly condenses into white smoke or small water droplets when it is ejected from the tailpipe and encounters cold air. The white smoke from car exhaust in winter is caused by water vapor adhering to the inner wall of the exhaust muffler. In fact, white smoke from the tailpipe in winter indicates good exhaust performance, so in most cases, white smoke from the tailpipe is not a fault. If the tailpipe emits a milky white oil mist, the main reason is poor fuel vaporization, where the fuel is discharged from the tailpipe without burning, forming a milky white smoke. This is more common when starting the engine in winter due to low temperatures causing poor fuel atomization. Usually, this disappears as the engine temperature rises after starting, and the tailpipe emits a large amount of water vapor white smoke, with water droplets at the tailpipe outlet. If the tailpipe emits an unusually hot white oil mist that turns into black smoke as the temperature rises, it indicates that the cylinder pressure is too low or certain cylinders are not working, and this should be checked and resolved.
