What is the difference between front fog lights and rear fog lights of a car?

Jan. 29, 2024

What is the difference between the front fog light and the rear fog light of a car? How to distinguish it? First of all, we have to understand what a fog light is and what is the main function of a fog light? The function of a fog light is to drive in weather conditions with low visibility, which can improve the driver's and Visibility of other traffic participants to avoid traffic accidents. So what is the difference between the front fog lights and the rear fog lights of a car? How to distinguish them?

car front fog lights

We know that the fog lights of new cars now generally use white light sources. On the one hand, it is for aesthetics. On the other hand, the halogen headlight source is white. To get yellow light, you must use a yellow lampshade to filter out the yellow light. In the end, you may only get about 30% light transmittance. In this case, the actual power of the fog lights is greatly reduced. The manufacturing technology of halogen bulbs is much more advanced than before. There is much less "noise" in the light source than in the past, and the Tyndall effect is not obvious. Therefore, using a white light source is a choice that takes into account both aesthetics and actual power.

Right rear fog light.jpg

car rear fog light

Then why don't the rear fog lights use white? Because the reversing lights have already been "first in line", so in order to avoid misunderstandings, red is used as the light source. After all, it is not a big problem to regard the rear fog light as a tail light or brake light (all three types of lights have the meaning of "keep the distance between the car and stay away from me"), and the conditions for turning on the rear fog light are met, which is why the tail light cannot penetrate When seeing through thick fog, the rear fog lamp should be a supplement to the tail lamp. If a white light source is used, in a foggy day, the driver behind will use the reversing light as the rear fog light and "follow" the car without knowing where it is going, which is very likely to cause a rear-end collision.

The function of the front fog lamp is not to illuminate, but to provide a high-brightness diffused light source. The intensity of this light source is enough to penetrate dense fog, alerting drivers on the opposite side. Although it can illuminate a small area, if used under normal circumstances, it is enough to dazzle oncoming drivers. In this case, it is unethical to turn on the front fog lights, so it is recommended not to use them under normal circumstances and only in dense fog. Even in heavy rain, you only need low beam headlights, fog lights will not give you any help. Rear fog lights are lights that can be seen from behind the vehicle in heavy fog, making the vehicle more visible. Rear fog lights refer to red signal lights installed at the rear of the vehicle. In environments with low visibility such as fog, snow, rain or dust, the luminous intensity is greater than that of the tail lights, making it easy for other road traffic participants behind the vehicle to spot the red signal lights. The function of the rear fog lamp is to make it easier for the driver behind the vehicle to spot his or her car in low-visibility environments such as fog, snow, rain or dust. The main function of the front fog lamp is to allow oncoming vehicles to detect you in time and provide auxiliary lighting in rainy and foggy weather. The main function of the fog lamp is to alert the vehicles behind in rainy and foggy weather, and does not need to provide lighting. The difference between red light and yellow light lies in the wavelength. The penetrating power of light is related to the wavelength. Red light has the strongest penetrating power, followed by yellow light. Therefore, the front fog lamp that indicates and illuminates the vehicle should choose a yellow light, while the rear fog lamp that indicates the vehicle behind only needs to choose a more penetrating red light.