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Originally Posted by dark.knight my conclusion is that these are measures for cutting costs and saving weight.. yes fog lamps weigh upto 3 kilograms and need a reinforced lower bumper section to hold them. It will also coincidentally improve efficiency due to lower battery use & lesser weight. It may be shocking to consider that a company like Mercedes-Benz will resort to such tactics to save weight but why not?
Either that or the companies are still at the cross-roads and deciding via experimentation on how lighting helps.. they obviously thought powerful, focused beams from a massive ballast will do the job.. they won't, not in all circumstances. Given so much of electricity draining, near-useless stuff in luxury cars such as multiple touch-screens, sunroof, massage seats (S-Class), mood-lighting!, puddle lamps etc, why not a simple lower fog-lamp for safety of others and the driver? I know for a fact that they work and so do many others as have been rightly said here. |
Umm.. I would beg to differ here. Of course, providing yellow lights would benefit in fog, but it is an evolving convention right from 'cost-cutting' brands like Maruti to 'premium' brands like Mercedes to provide white lights which are emitted by LEDs under the lens. It is not as simple as a 'Powerful beam with a massive ballast' nor is it some HID Bi-Xenon stuff. I have said this earlier in another thread yesterday, and repeating the same here.
When you speak about Mercedes giving bells and whistles and omitting on a fog lamp, my jaws dropped. Do you think that a manufacturer who gives you so many bells and whistles would omit on a pair of fog lights to save 3 kilos? There are hundreds of places where they could save more than 3 kilos rather than a fog lamp.
Lets forget this and get to the actual matter. The big brands are switching to LEDs for multiple reasons. It is nowhere cheap compared to HID or Halogen. Hence, lets take out the cost cutting thing off this discussion. When you speak of powerful beam, you should refer to Halogens or HIDs(more seriously) which actually are much of an annoyance. Let me explain how your theory is true, but the use case is something else:
1. Speaking about the directional beams of LED and Laser, you should keep in mind that this is not ONE single beam doing its job. Lets start from the Corolla sold in India - It has FOUR LEDs inside its Low beam cluster which can be focussed on four different areas. That means you dont have a single hot spot and four spots which can be angled differently. And since they are angled wide, the opposite vehicle doesnt get a bright glare but rather can see only a part of the beam since it is spread evenly and well.
As we go higher up the price chain, Mercedes had an array of around 40 LEDs to light up only the Low beam for the outgoing E Class. The new E Class has 82 LEDs inside the cluster. Now imagine whether it is better to have one huge light focussed at one direction at front or small, multiple lights which can illuminate different sections of the road.
2. Coming to the illumination range and width, like I explained earlier, it makes sense to have fog lights when your main beams cannot illuminate certain parts of the road like front short range and corners. But if you already have a main beam which can practically illuminate any section in front, and dynamically, why would you even need additional lights? That is why if we have a conventional Halogen or HID light, you will find fog lights to be effective. But if you add fog lights below a Multi beam LED setup, I dont think it will hardly make a difference.
3. I had written a post here
http://www.team-bhp.com/forum/techni...ghts-cars.html about the role of headlights in the cars of the future. If visiblity in fog is a problem, then you are offered a night vision system in the luxury barges. When that is itself offered, would the manufacturer compromise visibility for saving weight or cost cutting?
In the end, I find this idea of omitting fog lights a bad idea ONLY if the main beams are not able to do a good job of substituting the role of the fog lights. If they are, then it obviously makes fog lights redundant. For example, though the Suzuki Ignis and DZire come with LED headlights, they still come with fog lights since the main beams are very basic versions of LED lighting and are nowhere close to the higher end systems like I mentioned. Hence, fog lights are indeed provided here.
Same applies to the new Honda city. Though they provide LED headlights, they still provide extra LED fog lights since the headlights are again reflector based which may not give the coverage that the fog lamps will.
One important thing in the field of automotive lighting is how linear the lights are to the drivers eye when you see the road. If the lights are too low, it creates shadows from the point of view of the driver and that is the reason fog lights are not made to be too powerful. If you draw a line from the drivers head to where he sees the road closest to the car, you will find the headlights to be located almost inline. This is done to avoid shadows caused by small obstacles on the road like stones, or road humps and so on. These shadows can sometime conceal the presence of potholes and other depressions on the road surface especially in our conditions.
Hence, the developments on the forward lighting topic is now getting concentrated more at the headlight level rather than separate fog lights or light bars such. We find such jugaads only in India.

The intention is to improve lighting from the line of sight of the driver, rather than put multiple headlights all over the car, unless you have a specific off road requirement like rooftop lights etc. This will improve the way the driver sees things on the road.