RoadDawg

We recently bought a 2015/Lux. I am underwhelmed by the fog lights on this car so far, but maybe I am looking at this wrong as I have not worked with fog lights for a long time.

When I first used fog lights, they were yellow as it had been demonstrated that yellow light pierced fog better than regular light. Also, there was a sweet spot for intensity; too much of that and they lost their effectiveness. As far as I was concerned this all worked great. On the GX, the fog lights are white and only seem to operate when the headlights are on. The result is that they, well, they don't really seem to work very well if at all--the headlights just overwhelm them.

Intuitively I think an effective mod would be to install yellow fog lights and untangle their switching from that of the headlights. Am I missing something here?

hzhao

In principle, the wave length yellow light has the best penetration in fog, therefore the traditional fog lights are yellow. As for the issue with fog lights only being on with the headlights, it is specific to US DOT regulation. To the same truth, for US it is also regulated when high beams on, the fog lights will be off. Different countries and regions have different regulation on fog lights, such as rear fog lights, etc.

John00

I would like to see this demonstration that yellow pierces better, I don't think I've ever seen any actual test or test data that shows this; I have seen plenty of talk about wavelengths, particles, scatter, etc. and it didnt result in either the theory that yellow is better or an actual demonstration.
Your eyes might see yellow better but that's due to proximity to green which your eyes see the best, and the gain is eliminated by the lower yellow output.
Here's a bit of history on the yellow color:
http://www.danielsternlighting.com/t...ght_color.html

As for intensity, yellow generally comes from white then certain colors are removed, decreasing intensity due to plastic filters, paint, tinted glass, etc. which make you see yellow because the other components of the original white have been reduced. This reduction also slightly reduces the yellow component, but not as much. https://www.danielsternlighting.com/...fog_lamps.html

Whats important is your planned use for the lights. Really for fog? Then you need a specific beam pattern low to the ground, to be used in the fog, and this is when you are going < 20MPH because it won't project high enough to see a safe distance >20. I've never seen any fog light with good intensity for regular speed driving. Maybe you want driving lights?
Most people use the fogs for other purposes, thus they are on with headlights. For true low fog, you might not want the headlights reflecting back in your face.
other purposes:
as ditch lights on country roads to see deere, fox, etc. White with 2 sides of leds in the OEM are good, give a very horizontal pattern
to increase light in front on road: white with 3 sides in the OEM are good, gives a very round beam pattern. reaiming is necessary as there is a balance between road lighting and glare to others
as DRLs. Yellow or white, with a lower output. Beam pattern not as important for this use since it's about being seen and not about seeing, any pattern will be visible from other vehicles.


Once the planned use is determined then you can decide on the need for control mod

Zahid

I have the Lamin-X fog light films installed on my 2016. They are about 10 bucks which seems pricey for what it is (2 round films about an inch in diameter). They are holding up well and it turns the fog light color to yellow which I can see from the drivers seat at night. They have the option on Lamin-X website for other colors but I got the yellow one.

konc3pt

Did not know that yellower lights are better in fog conditions, was going to swap those out for whiter LEDs but received wrong type so don't think I am going to now

bbqsoup

Do you have any pics of the lights on with the yellow tint? Outside and from inside the cabin?

RoadDawg

I used fog lights on heavily modified Fiat 124 in the 70's. They were yellow and they worked great in the oft-fogged area of the Pacific Northwest. Turn the headlights on and that killed their effectiveness. I would say I have a fair to middling amount of experience with fog lights. Whether yellow is actually better than white or not, I do not know. However I do know that headlights are simply blinding. 20 mph? That's crazy fast for the kind of fog I am talking about. Good fog lights back in the day emphasized side lighting and were fairly soft towards the front. In advocating for white lighting, perhaps you could refute the wide held notion skiers hold; they prefer yellow ski goggles for snow glare reduction.

RoadDawg

I like that solution. Maybe try it, decide on it and do something more substantial if it works out. Thanks.

John00

I think we are in agreement. The angle and position of the white headlights creates washout, the light reflects back more than we want. The OP was about piercing, yet to see we need the reflecting, these are opposites. 20 was the suggested max for any fog, more fog = go slower. Fogs today also are all about low and side, I've posted the beam patterns before. As for skiers, that is a TOTALLY different, and mostly OPPOSITE situation. Rods vs cones, light out vs dark out, sunlight vs artificial light, full spectrum vs partial spectrum, sloped vs ridged amplitudes, wanting less light vs wanting more light, and on and on. Indeed there are studies that show that ~6500k is better for visual acuity than ~3500k, so much so that it takes about 400% more light at 3500 to have the same acuity as 6500.


Higher positioned lights reflect more light, so not as good.
Higher angle delta from ~horizontal to ground reflects more light, so not as good.
Higher power lights reflect more light so not as good.
Those three above can be adjusted to get white lights to have either better or worse performance than yellow lights.
Commonly, all three above are associated to white headlights then compared to yellow fogs, but it's not the yellow color itself that really helps.

RoadDawg

John00, it sounds like you have really checked this stuff out. I wish it weren't so, but I think I'm gonna just throw in the towel on any ideas in terms of mods for these. Mandatory use of headlights with them would seem to render them a vestigial gimmick and a bit of a joke, sorry to say. In recent years, the fog in the Coast Range isn't as bad as it used to be anyway.

John00

If you had an older vehicle, the difference would be more noticeable from lows to fogs. Fogs should have a wide beam, not extremely bright, a sharp cutoff, and be pretty low. The old vehicles low beam reflectors made more of a splatter and then you switch to the fogs and it was a remarkable difference. In this pic, these are both the OEM '12 GX fogs, one with a 3 side and one with a 2 side bulb outputting horizontally. It is on ramps so the height is more than usual.



the left is from a reflector with a multidegree bulb. much like an 80's truck. The right is more what we want for fog. less reflection in the face, get a deeper view.

many recent vehicles use projectors and not reflectors, so the lows become like fogs in many ways. this also reduces the perceived benefit compared to decades ago. Heres the GX lows and fogs, notice how the patterns are so similar



If i was in an area with much fog, i would aim the OEMs down, put in a yellow LED, OK I said yellow, because of the reduced light and cool factor, but you could use a lower power white, but most white sold are targeting max brightness.
you could also add in another set of lights with a sharp cutoff, and aim them slightly down and outwards. tie all these together with a separate control (5 min task) and should be good. you could see the road edge and crawl home.
I dont want to dissuade anyone from modding, thats for sure.

maybe even something like this but tweaked for real fog use

https://www.clublexus.com/forums/gs-...light-mod.html

Bill Dowd

I put in HID yellow bulbs and white HID bulbs in the headlights I got t hem from DDM Tuning Huntington Beach CA and they really light up the road ahead.
I can see twice as good using HID bulbs at night DDM Tuning have just brought new HID bulbs that are the best I have ever used.

ASE

Most of the "yellow" theories above are incorrect, with a simple reason as to why fog lights in the past were typically yellow.

Fog is made up of microscopic water particles that are in suspension. These microscopic water particles act like small mirrors that reflect and scatter light. This is why if you drive in fog with your high beams, the majority of the projected light is reflected back at you ... significantly reducing visibility. The old-school yellow fog lights were not as controlled as with modern lighting systems ... so the yellow color was used to "soften" this reflective effect.

Fog forms about 12-inches above the road surface ... so if you put your face close to the road surface in heavy fog, you can see a somewhat sharp horizontal delineation ... below 12-inches the visibility is crystal clear, and above is the (dense) fog with microscopic water particles in suspension. Modern fog lights have an extremely sharp horizontal cutoff, projecting the majority of light below this "fog line" to significantly reduce the reflection that impedes visibility. The old-school fog lights did not have this same level of light placement control ... so the yellow color was part of the solution in reducing the reflective effect of the projected light above the 12-inch "fog line".

With fog lights it's all about a razor sharp horizontal cutoff that projects the majority of light under the "fog line". If you have a good lens system with a sharp horizontal cutoff that is about 12-inches from the road surface, and your fog lights are aimed so the forward projection is truly horizontal ... then running yellow has no benefit and will only reduce the light output.

skrypj

That would be great if all we ever drove in was fog, but snow does not ignore the last 12" above the ground. I have been in some scary whiteouts here in Utah and the HID's and LED fog lights suck ***. The white light is terrible.

ASE

...totally agree, snow is a very different story.