Kelvin Ratings

3000K Has a golden yellow output perfect for use in fog lights. The yellow light penetrates through snow, rain, and fog more effectively than white or blue light. 4300K Has a slightly off-white output similar to that of sunlight. All cars that come equipped with HID headlights from the factory use 4300K bulbs. If you want the most usable light, 4300K is the kelvin rating for you. 5000K A pure white output, no tinge of yellow, and no tinge of blue. 6000K+ As you move into the higher kelvin ratings, your light output will appear more bluish-purple in hue, but the bulbs wont be physically as bright. As HID bulbs age, they go through what is known as "color-shift". When the bulbs are brand new, the output is whitish-yellow and as physically bright as it will ever be. As the bulbs age with use, their output turns more pure white/bluish and also starts to dim a bit. That's why cars with factory 4300K bulbs that are 5+ years old look like they're running 5000K or higher bulbs.

We commonly get customers looking for high kelvin [ie 6000K] bulbs because they want their headlights to be "brighter". There is a huge misconception here. As the Kelvin rating of a bulb increases, its Lumen rating decreases. Simply put: 4300K bulbs will put more usable light on the road compared to 6000K, 8000K, 15,000K bulbs. Period, end of story. TRS refuses to sell anything higher than 6000K because 1) We don't cater to obnoxious "enthusiasts" who want their headlights to look like a Christmas tree, and 2) it starts to defeat one of the main purposes of the headlight upgrade: better light output. Furthermore, choosing a high-kelvin bulb doesn't guarantee you'll get the exotic color flicker effect that everybody lusts after. The effect is produced entirely by the projector and lens combination.

When choosing a bulb from TRS, it does not matter whether you are using low beam or bi-xenon projectors. Unlike halogen headlights, with bi-xenons, nothing happens to the bulb when the high beams are activated. It does not get any brighter or shift positions. Simply put: you don't need "low beam" or "bi-xenon" specific bulbs. Our S2K-R low beam projectors and FX-R bi-xenons both use "D2S" bulbs.
It is also important to note an important difference between OEM and low quality aftermarket bulbs. The positioning of the capsule inside the projector is crucial to get a focused beam pattern without any uneven hotspots. All OEM bulbs have precision-set glass tubes to ensure the output will be in focus, whereas the aftermarket ones without the metal support structure are often mis-aligned inside the projector, causing a blurry cutoff line and other awkward shadows in the beam pattern. Here, our high-end Morimoto bulbs perform on par with the quality Philips units with their aligning metal base