On my 07, the foglights light up the pavement maybe 20 feet in front of the car at night. While it gives the appearance of being much brighter right in front of the car, I don't think it actually affects your visibility at a driving distance to a useful extent, especially if you are using high beams.
One thing I am noticing in the past couple of years is that many drivers are using fogs with their headlights at night, regardless of weather conditions. For most of us with less than perfect vision, even corrected, it makes it a lot harder to see due to glare when someone with fogs and headlights are on-coming on a clear night, or in our rear view mirrors.