The fog lights are designed with relatively low brightness due to dual considerations of safety and functionality. According to regulatory standards, rear fog lights must reach a minimum brightness of 50,000 candelas, but their power is limited to within 55 watts, and 35-watt bulbs are mostly used in practical applications. This setting not only ensures sufficient penetration in low-visibility environments (yellow front fog lights have a colour temperature controlled between 3000-3500K, and red rear fog lights are around 6000K) but also avoids the risk of glare caused by strong light. Fog lights usually use halogen light sources instead of LEDs because their colour temperature is closer to the golden range of 2800K-3000K, and the yellow light has a longer wavelength, which can reduce light scattering in fog. Although LEDs have high brightness, their colour temperature is high (generally exceeding 4200K), making their fog-penetrating effect weaker. For installation position, fog lights are deliberately placed at a low position under the bumper, reducing fog reflection interference by illuminating close to the ground. Their brightness needs to be distinguished from that of hazard warning lights-the latter have insufficient brightness and irregular scattering, and cannot replace the directional penetration characteristics of fog lights. Although some high-end models have eliminated independent fog lights, they integrate the fog light mode through intelligent headlights, still adhering to the optical principles of low colour temperature and anti-glare.
