5-90 is right about the diffused light for fog.... BUT if you want to make them brigher: :laugh3:
There is the little metal shield inside the light that sits between the bulb and the lense, only allowing reflected light to escape, stick a needle nose in there and wiggle it around till it snaps off, then pull it out. That will brighten them up.
Also, the sylvania silverstar's are very bright, I would think the combination of these two things would make some bright lights down there(though they may not be good for fog).
I took the metal piece out of the fog lights on my 98, and that helped a lot. I mainly used the fog lights just to have better visibility close up and cornering, not in fog, so I didnt mind less diffused pattern. I then bought the silverstars, but as soon as i did that, I cracked both the lenses on my lights(bad approach angle), completly destroying one of them. I still threw the bulbs in though to see what it looked like before i returned them, and they were very bright and white. Now I dont have any lights down there. :rattle: