what they are, which ones are mandatory and when to wear them

Fog is one of the most unpleasant weather phenomena when driving. It reduces visibility considerably and makes it necessary to pay extra attention to avoid possible mishaps. Luckily, there is an ally that helps us see and be seen: the fog lights. Of all the car lights, they are the most suitable for situations of low visibility, although you must know how to use them responsibly. There are still many drivers who use the fog lights lightly and when it is not strictly necessary. This situation makes may disturb other users of the road, since it must be taken into account that this type of lights are brighter than conventional ones. Next we are going to try to make a small summary on its correct use. Also remember something that seems to go unnoticed by many, that improper use can lead to a fine.

Types of fog lights

We can divide fog lights into two types:

Front fog lights

They are those white, low and wide lights that appear on most current vehicles (although they are not mandatory). They are used in poor visibility conditions, either in isolation or together with short and long range lights. These conditions include heavy rain or snow, fog, or clouds of smoke or dust.

Their use is broader, since they can be used at night on narrow roads (less than 6.5 meters wide) with successive signposted curves. Being quite powerful, they dazzle the car coming from in front and the one that sees us in the rearview mirror, so we have to be civil with their use. Misuse of the front fog lights may entail a fine.

rear fog lights

In this case, these are one or two red lights of greater intensity than the position lights that serve to make the car more visible from behind. In this case, they are mandatory in all cars, although their use must be specially controlled. It is reserved for especially unfavorable conditions, that is, very heavy rain or snow, thick fog, or dense clouds of smoke or dust. This is because this light can be especially annoying for the vehicle behind. In addition to being annoying due to its intensity, it can also be confused with the brake light in some cases. Its use is limited to those most extreme situations and has to be removed as soon as the fog/rain/snow disappears. You also have to remove it when you are in a traffic jam or retention for obvious reasons.

Fine for misusing fog lights

Under the regulations established by the General Directorate of Traffic (DGT), a driver may face fines for incorrect use of fog lights, as specified in the Traffic Regulations, article 106. Failure to comply with these rules may result in a penalty, either for not using the fog lights in the necessary conditions or for activating them inappropriately. To review the article, it tells us that front fog lights have optional restrictions and are allowed in cases of heavy or very heavy rain, fog or dense fog, snowfall or heavy snowfall, as well as in the presence of clouds of dust or smoke. However, its use is prohibited only in case of rain without adverse conditions.

On the other hand, the rear fog lights have a clearer focus: they should be avoided in conditions of light or heavy rain, fog, snowfall and clouds of dust or smoke. However, they become mandatory in conditions of very heavy rain, dense fog and heavy snowfall. If the authorities detect incorrect use of the fog lights, an immediate penalty will be applied, with a fine of 200 euros without withdrawal of points from the driving license. This highlights the importance of using these lights responsibly and activating them only when strictly necessary, thus avoiding inconvenience to other drivers and complying with road regulations. Now you are probably thinking about all those cars that use them as normal lights or as a complement to them. Yes, they deserve the €200.

Recommendations for maintenance

Just as it is important to know when to use the fog lights, it is also important when it comes to keeping them in good condition and verifying their correct use, which is why we leave you this list of quick and visual checks.

  1. check Periodic: Perform regular checks of all the vehicle’s lights, including the front and rear fog lights. Make sure the bulbs are in good condition and there are no connection problems. Lights that do not work properly can seriously compromise your own road safety and that of other road users.
  2. Alignment Correct: Adjusts the alignment of the front fog lights so that they are correctly aligned with the road. Improper alignment can dazzle other drivers and reduce the effectiveness of these lights in low visibility conditions. This can happen if when changing the bulb we do not install it correctly.
  3. Cleaning Regular: Clean your fog light covers to prevent dirt, dust and debris from affecting their performance. Dirty lights can disperse light unevenly, reducing its effectiveness, this applies to all car lights.
  4. Replacement Bulb replacement: If you notice that any of the fog light bulbs have stopped working, change them immediately. A complete and functional lighting system is essential to maintain good visibility in adverse conditions.
  5. Responsible use: remember to use the fog lights only when necessary, avoiding their use in normal driving conditions. This not only contributes to road safety, but also extends the life of the bulbs and the system as a whole.
  6. Adaptation to conditions: Adjusts the intensity of the front fog lights according to the severity of weather conditions. In heavy fog situations, you may need a higher intensity, while in moderate visibility conditions, a lower setting may be more appropriate.
  7. Revision professional: perform periodic checks of the lighting system in a specialized workshop. A professional can evaluate the overall condition of your fog lights, ensuring optimal performance and detecting potential problems before they become a safety concern.

(NOTE: Article originally published on 11/20/2022, revised and expanded)

Happy drivers

Client testimonials

Lisa D.


Theuth has completely changed how I follow automotive news. Relevant articles, thorough reviews, and an active community!

Hanna A.


I never miss a live show. It's like having front-row seats at every exhibition or race, but from my couch!

Andrew R.


As a novice in the world of motorbikes, Theuth's guides and analysis have been invaluable for my first purchase.

Ignite the drive, explore the ride