How so? The light is only 35 watts... Mine work fine is the fog.
actually.... the power consumption is 35 watts, watts are for current, not for light output
cut from wiki:
"presently they produce the greatest amount of light per unit of electricity."
"Beginning in the early 1990s, HID lamps have been employed in motor vehicle headlamps. This application has met with mixed responses from motorists, who appreciate the improved nighttime visibility from HID headlamps but object to the glare they can cause"
"Disability Glare describes effects such as being blinded by an oncoming cars lights, or
light scattering in fog or in the eye reduces contrast"
Light output is measured in lumens, which if I'm not mistaken, most 35w HIDs are about 3300-3500 lumens, whereas the most efficient halogen bulb only gets 2500 lumens from 68 watts (the info on the halogen is cut from wiki, not sure how accurate it is)
Last, but certainly not least, the typical yellow-orange hue of reg fogs helps to cut through the fog, whereas the white-blue of most HID kits scatter and reflect more in fog.
I tend not to use fog lights because where I'm from, if theres fog, no light is going to help you. Some nights it was so bad, I had to turn off my headlights and use my parking lights and hazards to navigate the rd at a crawl.
this is my opinion, take it as you will. If you use the fogs for as driving lights everyday, then is doesn't matter which you go with.