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HID Fog Lights?


wagonmaster87

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HID's in the fogs ftw! At least in the Outback. Much more output where you need it. I've got the DDM's in the fogs and some Denso ballasts/Philips bulbs in the headlights. You're not going to blind anybody if they're aimed correctly and there is a bunch more output than stock. No hot spots with my setup either.
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http://www.legacygt.com/forums/showthread.php?t=47541&highlight=hid+fog

 

Plenty of past discussion on this one. :) I recommend reading the entire thread with an open mind and no preconceived notions.

 

Pay special attention, though, to things starting on page 6 - new research findings, first hinted-at by bayley, and later brought to our attention by outahere.

<-- I love Winky, my "periwinkle" (ABP) LGT! - Allen / Usual Suspect "DumboRAT" / One of the Three Stooges

'16 Outback, '16 WRX, 7th Subaru Family

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TSi... being too lazy to read the entire thread, and trusting your opinion (as we have talked many times before on this level) what is your take away from the above posted thread?

life in spin cycle.....:spin:

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^ You have too high an opinion of me, bro! :redface: Honestly, without outahere's guidance and reference citations, as well as bayley's hinted testing results, that thread would've likely turned out very, very different.

 

The take-home points are basically all "page 6 and newer," and if you have a moment, I'd highly recommend reading from starting on that page, and if you have more time later, to re-examine the whole thread in the framework of the know-how you've picked up in those posts.

 

However, to be most brief, it appears that there's actually quantitative performance benefits to be had with brighter fog-lighting than what was conventionally believed (and that while selective-yellow does help in terms of subjective driver comfort, its preference by drivers is not of statistical significance, and furthermore, is a typically a trade-off for less "lumens-on-road" [which itself may be a good reason to increase light output, in order to compensate for this effect] - although asymmetric lighting [driver's side being much more dim than the passenger's] would likely also help, its implementation may be rather difficult). Furthermore, this benefit would be maximized - again defying old-time convention/beliefs - by raising the light to a higher-than-current-convention height in terms of where fog-lights should be mounted. Finally, seeing "ahead" isn't necessarily the issue under such extreme foul-weather conditions - rather, to be more feared is not being seen from behind, and being involved in a higher-speed rear-ending accident (thus the benefit of a rear-fog setup; and while it can be debated that better/more forward "fog" lighting should in-turn cut down on your chances of rear-ending someone, the actual honest truth is that you should slow-down much, much more under such extreme conditions, and not overun your vehicle's stopping capabilities...and that furthermore, the conventionally belief of selective-yellow foreground flood lighting [i.e. "true fog pattern" lighting] can and will lull you in to a false sense of increased driver confidence/comfort under such conditions, and can itself thus raise your speeds to a higher-than-ideal level).

 

My most humble opinion, in light of (no pun intended) current data?

 

HID fog-lighting shouldn't hurt anything - as long as the driver realizes that his own visual capabilities, no matter how wonderful the vehicle lighting, is severely compromised under such extreme weather conditions, and thus decreases speed to-match, and in this way, the extra lighting should thus also further help extend your forward safety envelope.

 

Remember as well that our "OEM" fog setup, if you will, isn't necessarily optimized for use in such extreme weather conditions, per current research data (i.e. low-cast, with a low mounting position to-start). Yes, the extra light cast by such an upgrade may help compensate, but it'll still be far from perfect.

 

But also, one should realize that the greatest risk does not come from where *you* are going nor what *you* can control, and is instead going to happen from the rear/following aspect.

<-- I love Winky, my "periwinkle" (ABP) LGT! - Allen / Usual Suspect "DumboRAT" / One of the Three Stooges

'16 Outback, '16 WRX, 7th Subaru Family

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^ Well put. Not to threadjack, but I must say, there have been many foggy commutes in my Saab where I was very happy I could turn on the rear fog indicator to make my car more visible. People stare at you like something is wrong with your car, but it does help them see you. As for why America doesn't require such a device...
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^ Well put. Not to threadjack, but I must say, there have been many foggy commutes in my Saab where I was very happy I could turn on the rear fog indicator to make my car more visible. People stare at you like something is wrong with your car, but it does help them see you. As for why America doesn't require such a device...

 

As most of us have agreed, indeed, current US vehicle lighting laws are quite dated, and should be revised.

 

I've fancied the rear fog myself (but I'll confess to, honestly, not having really gotten off my butt about it until brother outahere brought forward those lighting research articles, and impressed to me its importance), and I will be adding it to Winky in the near future.

 

Although I've thought about obtaining another tail-light in order to effect a more cosmetically acceptable modification, honestly speaking, my rear-end is already quite cluttered :redface:, and since I'm also going to add another pair of jammer heads back there, the visual clutter caused by the rear fog addition (PIAA DENO 3) will be a write-off.

<-- I love Winky, my "periwinkle" (ABP) LGT! - Allen / Usual Suspect "DumboRAT" / One of the Three Stooges

'16 Outback, '16 WRX, 7th Subaru Family

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^ :lol:

 

It's super-cluttered back there.... :redface:

 

My Blitz canisters, because of their size, already add a bit to the visual clutter, but what really gets it is the fact that I am not debadged, and even moreso that I already have two jammer heads around my rear plate, and utilize a plate-frame to both "integrate" them as well as to better-conceal my replica plate.

 

Currently, the wiring to the two jammer heads run up from the base of the trunk-lid to the plate frame via externally visible conduit, since I didn't want to drill through the rear fascia nor through the plate-light housings, but I think that when I add the rear fog and the remaining two set of jammer heads, I'm definitely going to be looking for a more concealed wire route......

<-- I love Winky, my "periwinkle" (ABP) LGT! - Allen / Usual Suspect "DumboRAT" / One of the Three Stooges

'16 Outback, '16 WRX, 7th Subaru Family

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..........However, to be most brief, it appears that there's actually quantitative performance benefits to be had with brighter fog-lighting than what was conventionally believed (and that while selective-yellow does help in terms of subjective driver comfort, its preference by drivers is not of statistical significance, and furthermore, is a typically a trade-off for less "lumens-on-road" [which itself may be a good reason to increase light output, in order to compensate for this effect] - although asymmetric lighting [driver's side being much more dim than the passenger's] would likely also help, its implementation may be rather difficult). Furthermore, this benefit would be maximized - again defying old-time convention/beliefs - by raising the light to a higher-than-current-convention height in terms of where fog-lights should be mounted. Finally, seeing "ahead" isn't necessarily the issue under such extreme foul-weather conditions - rather, to be more feared is not being seen from behind, and being involved in a higher-speed rear-ending accident (thus the benefit of a rear-fog setup; and while it can be debated that better/more forward "fog" lighting should in-turn cut down on your chances of rear-ending someone, the actual honest truth is that you should slow-down much, much more under such extreme conditions, and not overun your vehicle's stopping capabilities...and that furthermore, the conventionally belief of selective-yellow foreground flood lighting [i.e. "true fog pattern" lighting] can and will lull you in to a false sense of increased driver confidence/comfort under such conditions, and can itself thus raise your speeds to a higher-than-ideal level)...............

 

Excellent summation!

 

Driver comfort does not always equate to improved visual performance. The best example of this is the widespread use of white fogs on clear nights. Drivers are comforted by the strong foreground lighting, but objective testing has demonstrated a reduction in ability to detect obstacles further out on the road. The same reduction in visual performance is experienced if your dash lighting is too bright, or if your HID kit dumps too much foreground light 15ft in front of your car.

 

IMHO, the shortcoming of yellow fogs, be they coated bulbs or lamp films, is that they put less lumens on the road than a white fog. To exploit the full potential of yellow fogs, their lumen output needs to be increased. IIRC, humans can tolerate about 30% more yellow light than white light, at an equivalent glare or backscatter level.

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From a 2001 report, from the Transportation Research Institute at Univ of Michigan:

 

This document reviews various sources of evidence in an effort to evaluate the safety potential of current and improved front fog lamps. Crash data are reviewed to identify the specific safety consequences of fog, and studies of the visual effects of front fog lamps are reviewed. Finally, there is a discussion of the likely effects of current and improved front fog lamps on driver behavior and on overall safety. The conclusions are that there is very little evidence for a safety benefit from current front fog lamps relative to low beams, that there is little reason to expect that there would be a safety benefit even from improved lamps, and that, in terms of vehicle lighting, the most promising approach to improving safety in fog would be the use of rear fog lamps. In spite of a lack of evidence for safety benefits in fog, fog lamps are a popular optional form of forward lighting that many drivers apparently value. It may be that their main value is more as supplements to low-beam lighting for all conditions, rather than specifically in fog. Given the uncertainties in our present knowledge about how current fog lamps, and potential new fog lamps, affect vision and safety, it would be beneficial to learn more about those issues before adopting new standards for fog lamps, or retiring the current standards.............."

 

 

http://hdl.handle.net/2027.42/49453

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  • 1 month later...

Having been directed here I'll bump this old thread.

 

I am interested in HID lighting but i'm also looking to compliment them with yellow fog bulbs.

 

My reasoning is not for my personal visability but for everyone elses'.

I have found out that yellow fogs assist others in seeing me. I have noticed with fogs off (or on even, but white) more cars move into my lane at night not being able to tell how fast I'm approaching forcing me to increase my distance to them (I'm not too comfortable at 1 car length at 75+mph).

With fogs (yellow) on I see the cars lean toward the lane only to back off as they see me coming.

 

I only use the yellow to alert others of my approach and it's very effective.

 

Now just a note on the usage of fog lights, they are really only to assist in finding the lanes edge. To assist in locating that white line when visibility is at it's worst. Quick i.e. in the CA DMV handbook it mentions that if oncoming lights are too bright (someone with highs on) to look for the lane divider to keep your car on the road.

 

My .02

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