Agreed, although with the right color, an HID can be effective in dense fog. Anything over 3500K or so does more harm than good, just from the sheer intensity of the light. I wouldn't mind running a 4200K set in the fogs if I could manage fitting a Morimoto Matchbox projector in the fogs, then throw some amber Lamin-X film on. I'd be interested to see how it compares to straight 3000K bulbs with no film. The issue with factory fogs on most vehicles is they just kind of scatter the light. A properly tuned fog projector is considerably more effective, regardless of whether it's HID, LED, or halogen.