Does washing a car with hot water affect the paint?
2 Answers
If you wash your car with hot water in summer, there is no impact; however, if you do so in winter, it can affect the car's paint. In winter, the water temperature used for washing directly influences the cleaning quality of the vehicle as well as the paint quality. Washing with hot water in winter can cause the car's paint surface to expand rapidly due to the low surface temperature, leading to small cracks in the paint. When temperatures drop at night, the paint contracts again, resulting in damage. The correct method is to wear gloves, first rinse the car with cold water, then dry it with a towel. Start the car and turn on the heating system, then wash the car with warm water. After rinsing, if possible, use an air gun to blow dry the door and window seams. If water is not dried promptly, the doors can easily freeze.
As an ordinary person who enjoys washing my car by myself, I used hot water to wash my car a few times, mainly because I thought hot water could remove stains faster in winter. However, I later noticed some fading and small cracks on the paint. When I consulted a mechanic at the repair shop, he explained that hot water causes the paint to expand and contract too quickly, damaging the protective layer. High water temperature also accelerates chemical reactions, causing the wax layer to peel off and lose its shine. So now I stick to using lukewarm or cold water for washing, along with regular waxing, which keeps the paint looking brighter. Remember, don’t take shortcuts by using scalding water to wash your car—over time, the damage will be greater, affecting both the appearance and resale value. When washing your car, make sure the water temperature doesn’t exceed 40 degrees Celsius; keeping it cool is safer.
