I get what you're saying, but I also know that light output doesn't equal illumination. Using your logic, 500k bulbs will put out he most light, but it does me no good to have the road lit up orange/red. I'm going for light closest to sunlight/daylight which seems to be somewhere between 5000k and 6000k. If light penetration through fog and rain is your goal, you should be running 3000k bulbs.

I don't run my fogs other than on dark roads as shown above and I guarantee you that my stock incandescent did nothing to light up the road...sometimes I couldn't even tell they were on. As far as glare, I adjusted them down far enough that when I kneel down in front of my car to a seated level, I get no glare from my fogs.

 

OP: no HID fogs for me, regular H1 2500K bulbs.

 

If I may put in my 2 cents here:

I drove a BMW with 8000K lows and 10000K fogs for two years, and believe me, they were definitely an improvement from the stock halogen. Never had anyone flash highs at me, I could see pretty well on a clear night, but if it was actually foggy or raining, my fogs sucked. Hard.

I ended up switching to VLED 6000K blue tint for my fogs on the BMW, and it made a world of difference. I could see so much better in fouled weather conditions, something we get alot of during the non-summer seasons in Salem.

Now I'm running 6000K VLED HIDs in my G, and I can see a lot better than I did in the bimmer. And I'm probably gonna be going with 3000K fogs after seeing them in person on a G. It looks a lot better than it seems, and the only time you should have them on is during bad weather anyways. And nobody really cares how you car looks when that stuff is going down.

My recommendation: get VLEDs parking lights and D2S, and find some 3000K bulbs for your fogs if you use them in bad weather. If not, match them to the low/high.

 

lol, i really hope i don't run into that weather run now, because I have zero fog lights in, i'm still working on the install