Rear fog lights: what they are, what they are for and how to use them correctly

Cosa sono e come si usano davvero i retronebbia

Aaah, theWinter. There are those who hate it and those who love it, but we all have in mind the key characteristics of this fascinating season. Snow, bitter cold, shorter days, soups and seasonal vegetables such as broccoli or cauliflower. Apart from this, for those who live in the northern part of our country, winter rhymes above all with fog, and with it the mysterious systems that each of us has on our cars, but which many seem not to know how to use them: retronebbia. Welcome to Auto for Dummies, the techprincess column that explains the car world in a simple way. Today, we face an almost social issue, dear to every motorist in Northern and Central Italy: how do i use the rear fog lights? What are? And how are they used? We will find out everything today, trying to stop the sad and rampant plague of rear fog lights lit in the city center.

What is a rear fog light and what is it for?

Let’s start from the basics right away, starting to explain what is a rear fog light. As anyone who has driven at least once in the fog knows, fog is an ugly beast. Both day and night, the white blanket of droplets suspended in the air makes visibility very poor, which can compromise our vision and driving skills. In times of thickest fog, in fact, visibility can easily drop below 100 m, even dropping to a minimum of 50 meters. Under these conditions, driving is complicated to say the least.

The hardest thing we face when driving through fog is there difficulty in seeing the other cars, especially those traveling in the same direction as us. In fact, if the front lights have enough power to see even through the thickest fog, the rear lights are suitable for optimal or poor visibility conditions, not for a huge bank of fog. This is why the retronebbia: as the word itself indicates, it is a rear light of considerable intensity, among the most powerful of the headlights mounted on a car. Its use is as simple as it is essential: being able to traverse even the thickest fog banks, and to allow other road users to see your vehicle.

How are the rear fog lights activated?

It is therefore an absolutely indispensable device, so much so that for decades it has been mandatory on all new European models. Small pill: in America, the rear lights are already very powerful to overcome the great distances traveled in the United States. Because of this, the rear fog lights are optional, and few manufacturers choose to mount them. Only European cars and American cars also sold on European soil (such as BMW, MINI, FIAT, Alfa Romeo, Chrysler 300C, Audi and many others) are also equipped with rear fog lights in America, even if they are not widespread at all. More, it is possible to have only one fog light, usually mounted on the driver’s side or in the center of the car, or two, one on each side, so as to allow easy identification in the car space.

But how are the rear fog lights activated and deactivated? As with turning on “normal” headlights, there is no one-size-fits-all convention, and depending on the model you will find a new way to turn on the rear fog lights. In general, however, to locate the button (or the lever) used for the rear fog lights you have to look for the symbol you find above. This is the universal indicator for rear fog lights, adopted by any world manufacturer. To operate the rear fog lights, you will have to press the button or move the dedicated lever. To understand if the rear fog lights have actually come on, a yellow warning light will come on in the dashboard with the same shape of the indicator as before.

Whether it’s a lever, a button or a toggle on one of the light switches, this way you will understand how it turns on. Then there are some cars a little details, such as the first BMW MINI, the R50 / 53, which to indicate that the rear fog light is switched on will turn on a yellow LED on the small lever that operates it. Or again, on several Volkswagen Group models it is necessary to pull the wheel for turning on the headlights towards you. In any case, however, looking for the universal symbol you will never go wrong. If you really don’t find it, the car use and maintenance booklet will help you for sure.

Is it mandatory to use rear fog lights?

We come to the thorny part. Turning on the rear fog lights is in fact a simple practice, which is accomplished without great effort. The real problem comes when there is from understand how they are used and if it is mandatory to use them and on what occasions. Their use is not in fact standardized, like that of dipped headlights, and it is closely linked to a phenomenon that is difficult to regulate: atmospheric conditions. The Highway Code in fact provides for the use of rear fog lights only in three cases:

  • visibility below 50 meters;
  • heavy rain or haze;
  • particularly heavy snowfall

Since these three cases are not “homologable” such as, for example, the setting of the sun and the beginning of the night hours, the driver of the car is given a discretion to understand and choose when to operate the rear fog lights correctly. Therefore, there are people who will never have turned on the rear fog lights in their life, or other motorists who abuse them. For this, in a little while, we will give you some advice for correct use of the rear fog lights. The CdS, however, has inserted some rules with contexts in which the rear fog lights must not be used. In conditions of not very intense fog, for example, of light rain or snowand, or, of course, with clear sky, rear fog lights are prohibited. Furthermore, the Highway Code prohibits its use within an urban center. In any case and in every situation of visibility, given the low speeds and the artificial lighting of the cities, rear fog lights are banned from urban centers.

What are the recommendations for the correct use of rear fog lights?

We therefore understood that using them improperly is forbidden, and as we will see shortly it is also dangerous. How then are the rear fog lights used correctly and without incurring penalties? The first rule is that they must not be used in conditions of acceptable visibility, nor in the presence of artificial lighting. Rear fog lights should only be used when their usefulness is evident. It’s harder said than done, so I’ll give you a practical example very simple.

You are traveling on the motorway, and on the stretch you are traveling on a nice bank of dense fog falls. The sun has already set, and visibility is really poor. However, if you can clearly see the rear lights of the car ahead, the rear fog lights are superfluous. Visibility is at such a level that simple rear lights are enough. If, on the other hand, you can’t see the headlights of the car in front, then you need to turn them on to make you visible to whoever arrives. If, on the other hand, you are traveling on an extra-urban road, perhaps in the countryside full of curves, with fog or heavy snow, it is a good idea to turn on the rear fog light to make you as visible as possible from other road users.

However, there is a precaution that you must absolutely follow to be a good user of the road. In fact, if a car arrives and follows you at a short distance, you must absolutely turn off the rear fog lights. Not only is this behavior liable to an economic penalty, but it is also very dangerous for the health of those who follow you, and for their ability to drive.

Is it dangerous to use rear fog lights when you don’t need them?

We will all have experienced the experience of traveling and driving blinded by another driver’s left-on rear fog light. Precisely for its task of “cutting” the fog banks, these additional lights are really powerful. To give you an idea, international regulations require a brightness of between 150 and 300 candelas for rear fog lights. The rear position lights, on the other hand, are well below 50 spark plugs, while the brake lights oscillate between 60 and 150 cd.

Such a high power creates nin the human eye a “halo” effect that prevents the rest of the visual field from being seen with clarity and clarity. In addition, squinting or even lowering the sun visors, the driver who follows you could really lose control of what is happening in front of him, with the possibility of leading to accidents. The power of the rear fog lights is similar if not higher than that of the high beam headlights, and if fixed for a long time they can even end up damage the eyeball of those who follow.

It is therefore a very good rule to never forget turn off the rear fog lights when someone follows you at a short distance. Not only is it a lack of attention and knowledge of the rules, but it is also a very dangerous practice that can harm other road users.

Do I risk a fine if I use them improperly?

To avoid the wild use of rear fog lights, the Highway Code has provided for pecuniary sanctions not exactly ridiculous for those who do not use the rear fog lights correctly. In fact, if you were caught with the rear fog lights still on in the city, or in conditions of optimal visibility or in any case not sufficient to justify its use, you risk a fine that can range from 84 to 335 euros. There are no opportunities for further sanctions in the event of a repeat offense, but getting a rather hefty fine for such a foolish reason certainly won’t please you.

And you, will you still use rear fog lights in the city?

After reading this vademecum on the use of rear fog lights, now you know everything there is to know about these powerful rear lights. This device is one of the most useful for road safety, as it is able to ensure sufficient visibility in really difficult driving conditions such as fog and heavy rainfall. To quote Ben Parker, however, With great powers comes great responsibility. If used improperly, rear fog lights can go from life-saving to road safety’s worst enemies. Do you know someone who uses badly or does not use rear fog lights at all? Send him this article: he will no longer be able to say “I don’t know how to use them!”. And with this advice, the second episode of the year ends Auto for Dummies. If you liked it, comment below: we’ll see you soon, always here on techprincess. Hi!

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John Vassallo is a versatile writer who covers two fascinating realms: Automobiles and Electronics. With a deep knowledge and passion for both industries, John brings you the latest updates, trends, and insights in these dynamic fields. From the latest car models, automotive innovations, and advancements in electric and autonomous technologies, to cutting-edge electronics, gadgets, and emerging tech trends, John's articles provide comprehensive coverage to keep you informed.