more on fog lamps: piaa

source: piaa.com

driving lights

"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. (See below.)"

fog/foul weather lights

"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 driver's eyes, and the other is to minimize glare into oncoming driver's eyes. Both 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 necessary 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.)"