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I'm more interested in clear halogen bulbs; clear because they provide more light (yellow doesn't really do anything..), and halogen because the heat from the bulb keeps them from icing-over. I also need my fog lights to be independent from the headlights; working on the parking light circuit.
 

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Discussion Starter #22
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Post fog light install. The install took about a hour and a half for me. Hardest part was the under carriage bolt that held the majority of it in. Everything else was pretty straight forward. I'll take pics with the fogs on this evening.
 

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I'm more interested in clear halogen bulbs; clear because they provide more light (yellow doesn't really do anything..), and halogen because the heat from the bulb keeps them from icing-over. I also need my fog lights to be independent from the headlights; working on the parking light circuit.
Everyone has different requirements.

Initially, your concept sounds like a GREAT plan... the fact is that the foglights on Subies are tucked underneath so far that rain cannot get on them to cause 'icing over'. As long as the driver maintains safe following-distance, the water-spray from car-tires infront of you will not get on the foglights either.

The purpose of using yellow foglights is to prevent reflection from fog/snow. Yellow light does not reflect off of snow/fog back into the drivers eyes. Perhaps you have never actually driven at night in snowstorm/fog using ONLY yellow foglights. The driver can see THROUGH (and underneath) the snow/fog and the sides of the road. (the snow/fog is nearly invisible to the drivers eyes)

If your goal is to see as far ahead as possible... you should consider DRIVING LIGHTS which have a totally different light-pattern and are intended to light-up as far as possible infront of the vehicle.

BEWARE: Using DRIVING LIGHTS in fog/snow will result is driver being blinded by the super-bright reflection back into the eyes.
 

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"The purpose of using yellow foglights is to prevent reflection from fog/snow. Yellow light does not reflect off of snow/fog back into the drivers eyes. Perhaps you have never actually driven at night in snowstorm/fog using ONLY yellow foglights. The driver can see THROUGH (and underneath) the snow/fog and the sides of the road. (the snow/fog is nearly invisible to the drivers eyes) "

This is not based on any science I can find. The yellow color has no practical effect, it's the pattern. A wide low beam gets under the fog regardless of the color.
Richard Barrans Jr., Ph.D.========================================================= There is no good reason why fog lights are yellow. Here is an excellent explanation provided by Professor Craig Bohren of Penn State University: "First I'll give you the wrong explanation, which you can find here and there. It goes something like this. As everyone knows, scattering (by anything!) is always greater at the shor twavelength end of the visible spectrum than at the longwavelength end. Lord Rayleigh showed this, didn't he? Thus to obtain the greatest penentration of light through fog, you should use the longest wavelength possible. Red is obviously unsuitable because it is used for stop lights. So you compromise and use yellow instead.This explanation is flawed for more than one reason. Fog droplets are, on average, smaller than cloud droplets, but they still are huge compared with the wavelengths of visible light. Thus scattering of such light by fog is essentially wavelength independent. Unfortunately, many people learn (without caveats) Rayleigh's scattering law and then assume that it applies to everything. They did not learn that this law is limited to scatterers small compared with the wavelength and at wavelengths far from strong absorption.The second flaw is that in order to get yellow light in the first place you need a filter. Note that yellow fog lights were in use when the only available headlights were incandescent lamps. If you place a filter over a white headlight, you get less transmitted light, and there goes your increased penetration down the drain.There are two possible explanations for yellow fog lights. One is that the first designers of such lights were mislead because they did not understand the limitations of Rayleigh's scattering law and did not know the size distribution of fog droplets. The other explanation is that someone deemed it desirable to make fog lights yellow as a way of signalling to other drivers that visibility is poor and thus caution is in order. Designers of headlights have known for a long time that there is no magiccolor that gives great penetration. I have an article from the Journal of Scientific Instruments published in October 1938 (Vol. XV, pp. 317-322).The article is by J. H. Nelson and is entitled "Optics of headlights". The penultimate section in this paper is on "fog lamps". Nelson notes that "there is almost complete agreement among designers of fog lamps, and this agreement is in most cases extended to the colour of the light to be used. Although there are still many lamps on the road using yellow light, it seems to be becoming recognized that there is no filter, which, when placed in front of a lamp, will improve the penetration power of that lamp."This was written 61 years ago. Its author uses a few words ("seem","becoming recognized") indicating that perhaps at one time lamp designers thought that yellow lights had greater penetrating power. And it may bethat because of this the first fog lamps were yellow. Once the practice of making such lamps yellow began it just continued because of custom.

corroborated here:

Yellow Vs. White Fog Lights - AUTOINTHEBOX


How Fog Lights Work
Many lights are marketed as fog lights, but they are not all equally effective in helping a driver see in foggy conditions. The light pattern is what makes the difference in a good, effective fog light. Fog lights should have a wide beam pattern of 70 to 120 degrees, with a flat cutoff on top to reduce the amount of light directed up into the fog and thereby reducing the reflection of that light into the driver’s field of vision.
No light can penetrate fog. Fog lights should be mounted and aimed to illuminate the road under the fog, which tends to drift a foot or so off the ground. Fog lights should be mounted at bumper lever or lower and aimed straight ahead or slightly down, to be most effective.

The Yellow Wavelength Fallacy
Each color in the light spectrum has a different wavelength. Air molecules scatter colors of shorter wavelengths more so than those of longer wavelengths. White light contains all colors, the argument has been made that yellow light, with a fairly long wavelength, will be less likely to be scattered. The problem with this argument is that the moisture droplets that make up fog are too large to selectively scatter different wavelengths of color. This being the case, yellow light holds no advantage over white light.

The Disadvantage of Average Yellow Lights
Almost all yellow fog lights are made of a white light bulb with a yellow filter or lens. By putting a colored lens over a white light the output is reduced by as much as 30 percent, which makes the average yellow fog light less effective than the average white fog light.

I also have a PDF somewhere, I'm looking for it, they did some real life testing with yellow and white lighting all sorts of science but in the end they could not conclusively say yellow was better.
 

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This is interesting pretty much suggesting you best bet is really a rear fog light if you want safety :) Although, here in the US most people have no idea what they are. Driving behind someone during the day that has their rear fog light on just bugs me since they have no idea.
 

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This paper talks about headlamps not really fog lamps but does discuss color. It's pretty detailed however in the end

The s/p ratios of currently available yellow-filtered headlamps do not differ enough from conventional halogen headlamps for this effect to be significant in practical situations, but the design of filters that optimize both transmittance and s/p ratio might result in yellow- or perhaps orange-colored light that would provide a measurable benefit under perturbed atmospheric conditions.
<<<<<

Also consider if you read though this, this was under laboratory conditions not a practical situation.
 

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Discussion Starter #29
And they talk about halogens with film that's yellow wrapped around .doesn't say anything bout yellow LED bulbs. Btw, mine look great 😎
 

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I retrofitted a rear fog lamp in my 99 RS, even got the OEM switch for my dash. In the end I only used it a few times. Many times a rear fog lamp is incorporated in the rear cluster and there is a blank spot for the bulb to be installed. Some people sacrifice a back up light and wire a bright red LED there. Still there are the universal ones like this one.

Universal rear fog light on amazon
 

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Having said all that, I prefer the look of yellow, I have yellow in my Legacy and Outback's fog lamps. Had them in my BRZ too, Diode Dynamic LED's I do have white in my Miata, those are basically the upgraded LED ones subispeed offers.
 

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I guess I'll let ya know how these are once I install them. I also ordered a H11 LED yellow bulb that will replace the stock H11 halogens the fog lights came with.
Been running LEDs in my fogs with yellow tint for over 2 years now. They do illuminate the foreground very nicely, but since they are halogen housings the output is uncontrolled. I'm basically blind when the fog rolls in since the light goes everywhere, including up. Turns the fog into a blinding yellow ball so I actually have to turn off my fog lights to see in the fog.
Where they are actually useful is in the rain. I have a Limited so the headlight temperature is pretty cool and the yellow helps bring it down
 

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Pics please!
Basically it's just a harness that makes it so if you have a Sport with the DRL's (instead of fogs) they now stay on with the headlamps instead of turning off. I like the look.

This is the kit Click Me

It was pretty easy to install, I would rather have fogs though. The problem with the Sport is, if I do the upgrade kit like the OP has done, I loose the DRL's . Although there is this which could most likely be made to use both the DRL's and fogs with some creative wiring >> Click Me

22799
 

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"The purpose of using yellow foglights is to prevent reflection from fog/snow. Yellow light does not reflect off of snow/fog back into the drivers eyes. Perhaps you have never actually driven at night in snowstorm/fog using ONLY yellow foglights. The driver can see THROUGH (and underneath) the snow/fog and the sides of the road. (the snow/fog is nearly invisible to the drivers eyes) "
What a load of hogwash. In 50 years of driving (including PROFESSIONAL rallying winter/night events in Canada, using multiple auxiliary lights, as well as better than 1 million miles driving 18 wheelers in the snowbelt and Canada) I can tell you that short of radar, nothing will let you see THROUGH fog. While there might be a certain advantage in reducing eye fatigue, the reality is that the yellow coating on the lens which colors the beam also reduces the intensity of the beam.I'm talking about what WORKS, not what a bunch of arm-chair warriors who probably stay home when it gets foggy have to say.

But, despite all the obfuscation about yellow vs. white light, it all goes back to the earliest motoring laws from the 19th century. Until only about 40 years ago, French law still required only yellow lights within city limits. The English dropped these rules back in the 1930's, but people had become used to having yellow aux lights, so the style continued. But, like most pseudo-scientific ideas of the period (like phrenology, perhaps?) we know better today.
 

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What a load of hogwash. In 50 years of driving (including PROFESSIONAL rallying winter/night events in Canada, using multiple auxiliary lights, as well as better than 1 million miles driving 18 wheelers in the snowbelt and Canada) I can tell you that short of radar, nothing will let you see THROUGH fog. While there might be a certain advantage in reducing eye fatigue, the reality is that the yellow coating on the lens which colors the beam also reduces the intensity of the beam.I'm talking about what WORKS, not what a bunch of arm-chair warriors who probably stay home when it gets foggy have to say.

But, despite all the obfuscation about yellow vs. white light, it all goes back to the earliest motoring laws from the 19th century. Until only about 40 years ago, French law still required only yellow lights within city limits. The English dropped these rules back in the 1930's, but people had become used to having yellow aux lights, so the style continued. But, like most pseudo-scientific ideas of the period (like phrenology, perhaps?) we know better today.
Well said, but yellow fogs still make me feel cool. Something about the contrast. Plus the output on the stock fog lights kinda stinks anyway so any upgrade (yellow or not) is an improvement for me.
 
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