Q: When Should Fog Lights Be Used?

There is a great difference between "fog lights" and "driving lights." Not only are the lights themselves different, but the reason for their use differs, as well.

Fog lights are only used in certain scenarios. For example, in times of low visibility typically due to weather conditions, such as fog (go figure), mist, rain, etc. fog lights are needed. Fog lights are used in conjunction with the low beam headlamps. The light dispersion of fog lamps is very wide, but the light beam is directed only a short distance in front of the vehicle to enhance the visibility of the road directly ahead of you.

Driving lights, on the other hand, are used in conjunction with the high beam headlamps. High beams project light for a long distance in front of the vehicle. This leaves the area directly in front of the vehicle less visible. Driving lights have a more narrow dispersion area than that of fog lights, but they do illuminate more of the road in front of the vehicle, thereby augmenting the high beam headlamps.

Most vehicles that come with factory-installed auxiliary lights are fog lights, not driving lights. Check with your local and state laws concerning the use of driving lights on your vehicle before having them installed. If you run into any problems reach out to a certified mechanic, they will be able to ensure that your fog or driving lights are working properly.