What to Do If the Windshield Fogs Up Before Driving?
2 Answers
Here are the methods to defog the windshield before driving: 1. Use a specialized defogging agent: There are dedicated defogging agents available in the automotive beauty market. Spray this agent on the inner surface of the car glass and wipe it clean. While removing dirt from the glass, it also forms a thin transparent protective film that effectively prevents the formation of fog caused by condensation. One application can prevent fogging for about 10 days. 2. Turn on the air conditioning while blowing warm air: According to the car manual, the method to defog is to adjust the air conditioning vents to the windshield position and turn on the air conditioning switch to activate the compressor for dehumidification. However, if the temperature control knob is set to the cold air position at this time, the passengers inside the car will feel very cold. Therefore, the temperature knob can be placed in the warm air position to achieve both defogging and warming. 3. If the fog inside the car is not heavy, you can open a small gap in the side windows to allow air convection between the inside and outside of the car, reducing the temperature difference and causing the fog to gradually disappear. The principle of this method is the same as turning on the air conditioning cold air, but it does not increase fuel consumption.
When I first started learning to drive, this always bothered me, especially on rainy days or in winter. As soon as I got in the car, the windows would fog up, making it impossible to see anything. Don’t underestimate this issue—poor visibility can easily lead to accidents. I learned a few practical tricks: first, start the car, turn on the air conditioning to hot air, and direct the airflow at the windshield for a few minutes. The hot air will evaporate the moisture. If it’s too hot in summer, cold air works too. Remember to press the defog button—it’s specifically designed for this. Keep the car interior dry in general, wipe the soles of your shoes before getting in, and avoid opening windows too much when it’s raining. Keep a soft cloth handy for quick wipes if you’re in a hurry. Understanding the cause helps—it’s due to the temperature difference and humidity inside and outside the car. Keeping things dry and well-ventilated is key. Once you develop these habits, it’s much safer. If fogging occurs, pull over immediately to deal with it—don’t risk driving.
