HID Kits, Xenon Bulbs and Halogen headlamps — The Story

August 28th, 2011 Comments Off

So I’ve done a handful of research lately on halogen and Xenon lights.  Below is a basic summary of my findings when investigating (and eventually buying) replacements for my stock Halogen headlamps in my 2006 Mercedes C55 AMG.

Disclaimer: I pulled this together from bits and pieces here and there.  I do not claim to be an authority on lighting, but I think most of this is reasonably accurate.

Info about Xenons

  • HID = High-Intensity Discharge (for purposes of this doc, HID == Xenons)
  • HID Kit == Xenon Bulb (mine are size ‘D2S’ for low beam, H7 for high beam) + Ballast + Wiring.
  • If you already have headlamps with HIDs or are replacing the bulbs in an existing HID with a different color / temperature you do NOT need a whole new kit, just new bulbs.
  • Higher temperature == more color and less light
  • Stock color / temp is 4300Kelvin.  5000Kelvin is a brighter white, 6000K starts to look a bit blue and 8000K is getting fairly blue.  I went with 8000K :)
  • HID kits are generally a bit flaky, but are very cheap
  • Stock halogens are 35W, and to avoid complications its not a bad idea to stick with 35W if your upgrading to Xenon.  If the ECU notices a different power draw from the headlights it might throw errors.
  • Mercedes should be coded from Xenons (via STAR / ODBII computer systems) to avoid error codes.
Info about upgrading from Halogens to Xenons
  • If you have halogen lamps you can take out the halogens, buy an HID kit and be good to go, total cost of upgrade on the order of a couple hundred bucks (2-300) TOPS.
  • HOWEVER — You could also replace the whole headlamp assembly, which has several advantages:
    • Stock halogen headlamps do not use projector lenses.  Projector lenses look significantly better with Xenons than the traditional ones.
    • OEM Xenon headlamp kits come with their own ballast etc. which is generally more reliable than a HID Kit.
    • Mercedes OEM Xenon lamps have leveling motors etc, which is a nice to have but a bit gimmicky.
    •  I bought a used OEM Xenon assembly from a friend on mbworld.org — going to install them later this week.  Hoping for the best!