LED Fog Lights

Front-facing fog lights or fog lamps are designed for emit light in a bar-shaped beam, which has a sharp cutoff on top, and the actual lights are under the headlights' position and aimed toward the ground at a sharp angle. 

They are different with high beam or low beam headlight, headlights are aimed at a relatively shallow angle and illuminate the road surface a great distance in front of a vehicle. Yet the fog lights only illuminate the ground immediately in front of a vehicle. Fog lights are designed to illuminate a wide path of road with a relatively short distance.

The bar-shaped beam of light makes a fog lamp a fog lamp, rather than the color.

The stock fog light color maybe yellowish one, yellow lens too. They can be white as well.

Currently, more and more states or areas requires to use the fog lights in the condition of fog, rain, snow or mist, or in other severe weather that might warrant their use. The fog lights are aimed low, and many of them use selective yellow light, they are relatively useless when the driving conditions are good;  that means no need turn on your fog lights unless you experience a poor visibility situation when driving.

So, fog lights should be used only in foggy, rainy, snowy or misty conditions or other severe weathers when there is poor visibility. Fog lights have a limited range and are most effective at low speeds. In poor visibility fog lights do the job of dipped beam headlights. Due to this design, fog lights reduce the glare-back from fog or falling snow which makes them a better choice in such conditions.  But only if mounted properly 18-20” off the road

Steam Fog Light
This would occur in all lighting applications. As you may already know, there is a difference in temperature between the LED lamp housing, and the outside temperature. During cold weather, or night, the temperature noticeably decreases, which created a discrepancy between outside and inside air. This discrepancy causes steam to arise. 

It is also more noticeable during night, and usually gets fixed by itself, when the outside and inside temperatures have less of a varying difference. Please don't worry if you see this in the housing, as it has absolutely no effect on the product itself. Here's how it looks like: 

Condensation Fog Light
Now condensation on the other hand, is when you should start to get worried. It is occurred by a crack or opening on the housing, which as a result, allows water to get inside. For some models, you should be able to see a moisture cap that would move from it's place during wear and tear of a car, hence causing water leakage. A good remedy around this would be to detach the housing and using a blow dryer on it, or to simply let it dry out. 
Here's how it would look like: 

Driving lights provide illumination forward of the vehicle and intended to supplement the high beam of a standard headlamp system. It is not intended for use alone or with the low beam of a standard headlamp system. 

Driving lights improve the range of light beyond what your high beam headlights offer. They help see obstacles and signs well before they become visible than with normal high beams. They have a rectangular beam which produces a beam of powerful intensity with a longer, wider reach. Driving lights illuminate the side of the road making them more visible. In general, driving lights are designed to provide better visibility than high beam headlights and by extension, a safer driving environment. Driving lights are the ideal choice when driving on highways at high speeds. Like a high beam, they have to be dimmed in the face of oncoming traffic.

In current usage, "driving lights" refers to additional large circular lights placed up front, like those found on rally cars and off-road vehicles. There are many sizes and styles available, with most being a universal fitment that adapts to a Subaru WRX as well as a Ford F-150. While they do increase visibility at night, driving lights are for clear weather conditions.

Fog lights differ from driving lights in the internal construction and intended placement. With a beam cutoff angle in the top of the housing, fog lights are designed to sharp beam cutoff broadcast light only onto the street. Another common element is yellow lenses, yellow bulbs, or both. Many drivers assume all fog lights are yellow, but they don't have to be. The science behind the yellow tint is due to the wavelengths of light colors. Yellow light is a longer wavelength than blue or white light. In theory, the longer wavelength means it can penetrate a thicker atmosphere or even water, which is why submarines use super-long wavelength radio waves to communicate.

As we know, front-facing fog lights are designed to allow you to drive with more light through extremely poor visibility weather conditions, how about the rear fog lights?

Rear fog lights or rear fog lamps are designed for preventing anyone from hitting your vehicle behind under the same server conditions. This because in a very poor visibility conditions, the tail lights may not be easily noticed and can't alert the drivers behind you until it is too late, which happens a lot at driving at a unsafe speed for the prevailing conditions.

Normally, rear fog lights comes red color, which makes them superficially similar to brake lights and tail lights.

It depends on your vehicle with CANBUS system or not when you want to upgrade your stock halogen fog lamps to LED fog lights bulbs, Normally in the market, the European vehicles like BMW, Mercedes-Benz, Volvo, VW, Audi, Mini-Cooper, etc. extra load resistors/decoders probably are required to avoid the error code or flickering on and off issue.

This happens due to led bulbs draw much less power than stock lamps, for such vehicles are equipped with CANBUS system which will detect the currrent difference compared with stock lamps and will cause the error code or malfunction. Adding extra load resistors or decoders to add more working power and the CANBUS system will not detect it when it matches its requirements.

The stock factory fog lamps are dim yellow color, when you upgrade to LED, white and yellow color are both legal for on-road and off-road use, yet for other colors like 8000K ice blue or 10k blue, which depends on the states' laws. 

So if you want to upgrade other colors except white or yellow, please check your local laws to confirm it before purchasing.

This is rare situation for 2004-2008 Ford F150 pickups, but it happens for some trucks, which is caused by the fog light's ground wire shares the same as the high beam headlight's. Here are 2 solutions:

1. Adding an inline resistor with your high beam headlights to reduce the electric load
2. If the about solution doesn't work, then please separate the ground wire for the fog light with high beam.