Traditional fog lights are usually mounted under the front bumper
about 10-24 inches from the ground. There are two important issues to
address when installing fog lights, the first is to minimize the
amount of return glare into the drivers eyes, and the other is to
minimize glare into oncoming eyes. Both of those issues must be
accomplished while putting as much light as possible on the road.
These fog/foul weather light aiming instructions are suggestions taken
from common practice and the S.A.E. standard J583. Some modifications
to these instructions may be neccessary to minimize glare.
Visual aim is made with the top of the beam 4 inches below the lamp
center at 25 feet with the lamp facing straight forward. (See below)
Typically, driving lights are mounted above the front bumper about
14-30 inches from the ground to provide extra high beam illumination.
Driving lights can be mounted below the bumper, although they will not
be as effective because the light will hit the ground sooner and reduce
the range of the light.
Visual aim is made with the center of the beam hot spot 1.5 inches
below the lamp center at 25 feet with the lamp facing straight forward.
Proper auxiliary lamp aiming is the most important part of an
installation. If the lamps are not properly aimed they will not achieve
optimum performance and they can be very dangerous. The danger comes
from the beam pattern being aimed right into oncoming vehicles thus
blinding the driver.