Don't go by what you see on the road, get the car about 25' in front of a wall and see where the pattern ends up. You want the beam to be below your low beams. Otherwise they won't help in fog and they will blind people too.


Look here:

http://lighting.mbz.org/tech/aim/aim.html

small cut and paste from that site.

FOG LAMPS

Fog lamps are aimed using a procedure very similar to that used for European-spec ECE and US DOT VOL low beam headlamps, but the vertical drop is different. Follow the vehicle-preparation and wall-marking instructions given above for ECE/VOL low beam headlamps, substituting "foglamp" for "headlamp", but with the following changes:

If the fog lamps are mounted below the bumper, your b-b line should be 2" below the fog lamp axis height.

If the fog lamps are mounted above the bumper, your b-b line should be 4" below the fog lamp axis height.

Fog lamps produce a wide, bar-shaped beam of light. Horizontal aim is much less critical than it is with headlamps. The fog lamps should be pointed straight ahead, not leftward or rightward.