Our 55w HID Kit is not recommended for smaller fog light housings because they tend to concentrate a large amount of heat in a small area.

That is a Quote from DDMTuning.com

You'd figure, once again, that they would also provide some proof. Perhaps a damaged fog light housing?

Here'* the concept, and until I get my car back from Ohio and can test the lense temperature between a 55W Halogen and a 55W HID, this is as good as I can do.

Halogen bulbs, unlike normal light bulbs, use halogen gas, a tungsten filament, and a quartz encasing. The reason why the encasing is quartz is because if it were glass, it would melt as a result of the heat. The current passes through the filament, heating it to the point to where it creates light. Notice, it has to get hot in order to create that light. The Halogen gas inside the bulb is there to prevent oxidization of the hot filament. To make a comparison, this is like a space heater, if you've ever used one.

HID'* use a completely different method. The bulb consists of two electrodes placed in very close proximity to each other. The gas used here is Xenon. Unlike with Halogen-filament bulbs, the light is created by the gas, not by a filament. HID'* use a ballast which consists of a series of high current capacitors, transistors, and resistors. To light a Xenon bulb in an HID kit, the ballast takes in a small amount of power and sends a very intense charge of electricity across the electrodes. This is why they're called High Intensity Discharge. The electrical charge excites the gas molecules inside the bulb and causes them to discharge photon particles, producing light. The entire capsule of gas is then "lit," taking up to 30 seconds, and because all of the gas in the capsule is used to create the light instead of just one filament, you end up with much brighter overall light output. The ballast regulates a constant flow of power only to keep the gas molecules excited, while a standard filament based light requires a constant intense electrical current to keep the filament hot.

When I get the Regal back on the 17th of July, I'll run a test for you guys.

Credit where credit is due: http://www.essortment.com/hobbies/hi...sityd_siyc.htm

Not being able to edit my posts is very annoying.

Regardless, I wanted to add something else.

It is true that the gas that burns inside an HID bulb is extremely hot, and the capsule may also be extremely hot. However, the temperature of the capsule and the gas inside does not directly translate into ambient heat emitted and absorbed by the surrounding headlight reflector and lense the way it does with the halogen filament bulb.