Fog lights help you see in thick fog (or rain or snow) conditions. I'm pretty certain it's the reason they are called fog lights. Fog lights are aimed low and shed wide angle light to the sides to allow you to see the edge of the road close to the car. Fog lights are aimed low to keep reflected glare to a minimum (next time you are driving at night in thick fog, heavy rain or snow, flick the old high beams on for a second and see what this reflected glare looks like and what it does to your forward visibility, but only when it's safe to do so, like in your driveway or while stopped someplace). Fog lights are used when you are driving slowly, due to poor visibility using low beams as primary lighting. If you need extra light while driving in clear nighttime conditions, you should install a set of good quality SAE approved auxiliary driving lights. These lights are focused way down the road (like your brights) and actually add light farther away and out to the sides a bit more, where you really need it driving at normal speeds. Your eyes adjust to bright light close to the car by narrowing the pupil. This generally makes it more difficult to see into the night. The reason there is a "dark" area just ahead of the car (really only a few feet) when you use your bright lights, is to allow your eyes to see farther into the distance, where the brights are more effective. Make sure your primary lights are aimed properly and polished, so they work their best. Hazy or pitted light covers will diffuse or scatter the light to places that won't do you much good. There are a bunch of products out there, intended for this use, that make this job super easy, and really keep your car lights very clear. It's pretty weird to see so many drivers with their fog lights turned on in crystal clear night conditions for that "extra" light magic. I'm pretty sure the reason most drivers who run those poor fog lights on clear nights are doing it for the perceived cool factor or whatever. Check out all that oncoming traffic at night and see if all that extra lighting coming at you when it's not foggy really makes sense. It's all extra glare at you, making it more difficult for you to see. And we will now hear... "oh, but I can really see better with them on all the time... yada yada yada." Run'em if you must, but do the research to see if you are really gaining much from burning the fogs all the time. Myths love to run rampant.
'08 Manual, Sun&Sound, 17" Borbet Type CA wheels, 215/50 Summer Tires... 16" OE steel, 215/55 Snow Tires