HID stands for "High Intensity Discharge". HID lights get their name from the intense white light produced by the electrical discharge.
HID lights are a different type of lighting technology utilized in automobiles for greater effectiveness and greater efficiency. Unlike Halogen (or incandescent) bulbs, HID bulbs do not have filaments.
"Instead of heating a filament as standard halogen bulbs do, HID bulbs create light by bridging an arc between two electrodes similar to the energy transfer of lightning. The arc stimulates a mixture of Xenon gases and metallic salts, producing a phenomenal bright white beam of light approximately 3x brighter than conventional halogen illumination, while lasting 10x longer!" Source
The Advantages Of Xenon HID Lights:
- More light output (up to 3 times brighter)
- Wider coverage (beam pattern illuminates up to 70% more of the roadway, especially the sides)
- Whiter light (almost a blue light, resulting in clearer images)
- More durable (withstands shock and vibration since there is no filament)
- Longer life (last 3 times longer or 5-10 years, depending on use)
- Greater efficiency (3x more light while using 24% less power)
A Word About Xenon -vs- Halogen Bulbs...
Light bulbs are usually filled with a mixture of gasses, selected to help retard the evaporation of the filament and to minimize heat loss from the filament. Argon works OK for this, krypton works better, and xenon better still. The better gasses are more expensive, of course.
Halogen, on the other hand, isn't a particular element or chemical. Halogen bulbs include small amounts of one of the halogen family of elements (usually iodine) in the fill gas. The halogen gas in the bulb can actually bond temporarily with evaporated filament metal, and redeposit the metal back on the filament. This extends the filament life and keeps the bulb's glass free of the filament deposits that make other bulbs turn gray as they age.
In any case, the goal of both strategies is the same: to allow the filament to have a reasonably long life when burning at the highest possible temperature, burning more brightly and more efficiently.
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According to this Motor Vehicle Comparative Analysis: "92% of those who have it will order it again."