The Guide to Adding Auxiliary Lights
More often than not, new vehicles do not come from the factory with a full array of lights. This keeps the production costs down, but leaves us unprepared for some of the most common driving situations, such as rainy weather, foggy roads, and even nighttime cruising. Auxiliary lights pick up where your auto manufacturer leaves off.
There are two basic types of auxiliary lights: fog lights and driving lights. Let's take a closer look at the unique characteristics of each type:
Anyone who has driven through a thick patch of fog knows that switching on the high beams does not improve your visibility–it makes it worse. That's because the light from your high beams reflects off the water droplets in the fog, bouncing right back into your eyes. The same thing happens when you're driving through other foul weather, like rain storms or snow flurries. Traditional low beams and high beams just can't cut through. Fog lights are the answer to driving through pea soup and foul weather.
The only effective way to drive through dense fog is to angle the light downward onto the road, so that it avoids running right into the reflective water droplets. Typically, fog hovers about 12"–18" above the road's surface. Fog lights mount low on your front bumper, and cast a wide beam of light down onto the road. That way, the light gets lower than the fog, and you're able to see clearer and drive safer. What's more, in order to keep the light from extending above the level of your bumper, the beams of light are cut off at the top (imagine an Oreo cookie that's been divided in half).
How your fog lights are aimed is extremely important. If they're angled too high, their light will just shoot right up into the mist—not to mention right into the eyes of oncoming motorists. If they're angled too low, then their range is greatly reduced, and you won't be able to see far enough ahead. Thankfully, the Society of Automotive Engineers (S.A.E.) has taken the guess work out of aiming fog lights by developing a standard system. Here's how it works:
- Mount the fog lights on the front of your vehicle between 10"–14" up from the ground.
- Park your vehicle 25' away from a flat wall, like a garage door or the side of a building. You'll want to make sure that the ground is level so that the results are accurate.
- Measure the height from the center of the lamp to the ground. Use that same measurement to draw a line on the wall with some chalk.
- Turn on the fog lights, and take a look at where the light hits on the wall. The tops of the beams should be 4" below the line you drew.
A properly aimed set of fog lights not only gives you better visibility, it's also good roadway etiquette. Misaligned fog lights can shoot right into the eyes of oncoming drivers, and no one wants blinded motorist on the road, especially on stormy nights.
After the initial alignment, periodically check to make sure that the lights are still aimed correctly. Since fog lights mount so low to the ground, they are at greater risk of being knocked out of position.
A number of well-respected companies craft quality fog lights, including Hella, PIAA and KC HiLites.
Safe driving is dependent on our ability to react to any situation, but we can only respond to what we can see. Low beams and high beams are our first line of defense against poor visibility, but often their range falls short. Driving lights pick up the slack. They're designed to boost the intensity and range of your high beams, showering the roadway with brilliant light. When we can see clearly, we're able to rapidly respond to whatever may come our way.
If you think about it, driving lights give you the power to peer into the future. All their extra light reveals the road that lies ahead of you, and you can use that knowledge of upcoming conditions to plan your next course of action. Without the foresight that driving lights deliver, your ability to respond to hazards is greatly diminished. Because of this special characteristic, driving lights are most effective for nighttime highway driving because of the higher cruising speeds.
Driving lights generate beams that are more focused than fog lights because they're engineered to travel farther in advance of your vehicle. As such, correctly aiming them is crucial to improve your own visibility while avoiding blinding other motorists. Follow these S.A.E. tips to properly align your driving lights.
- Mount your driving lights on the front of your vehicle 14"–30" up from the ground.
- Park 25' away from a flat wall, like a garage door or the side of a building. Level ground gives you the most accurate results.
- Measure the distance from the center of your driving light down to the pavement, and mark that distance on the wall with chalk.
- Flip on the lights and find the center of the hot spot, which is the intense inner circle of the beam. Tilt the driving light so that the center of the hot spot is 1 �" below the mark you made in the wall.
While there is little variation in the beam pattern of fog lights, driving lights come in a number of different styles that are optimized for specific driving conditions.
This standard pattern increases the range and brightness of your vehicle's high beams. It's designed for higher nighttime cruising speeds, and it helps you clearly see signs and hazards long before your normal high beams.
This pattern is designed to produce an exceptionally strong beam of light with wider coverage than the normal pattern. In fact, it projects its beam up to 1,500' away at a width of 250'. The beams are angled upward and to the right, illuminating the side of the road and making it much easier to see street signs and pedestrians.
This beam pattern is designed to improve your front and side vision, especially for winding roads, tight curves and cornering. Plus, you can get an intelligent lighting system that automatically senses when you're driving around a bend and turns on a fill light to illuminate the curve.
This pattern puts out a powerful, narrow and extremely long stream of light that's designed for reaching maximum distances. The range for a single beam can extend up to 2,500' long by 120' feet wide. Because of their power, pencil beam lights are recommended for off-road and racing use.