another sunny said:
Somebody will correct me but if you have the low hid kit i was told that you lose high beem, is that right? i have decided to wait and go for the hi and low setup for £97 ish and i think i will go fo 6000k as this gives good light but still quite blue.... i think!
That's right, if you go for a standard H4 set, you'll normally get the low beam only bulb. If you go for a hi/lo kit, you'll get a HID low beam and halogen main beam. If you go for a bi-xenon kit (the best and preferred imho), you'll get HID light for both the low and high beam.
The bi-xenon kits usually use a sliding reflector, activated by a small solenoid, to change the output of the bulb from dipped (low) to main (high) beam. So, you only really have one lighting element in the bulb itself.
Personally, if the 5000k is available, I'd go for that over the 6000k kit as, it will give more light output and the light will be white in colour. It's a common misconception that the OE hid lighting on cars like BMW's and Mercs has a blue or purple tint. They dont. They use 4300k bulbs which give a pure white light (when used with specific HID optics) but, due to the refraction caused by the lamp optics, the light gets a coloured tinge to it at certain viewing angles.
4300k bulbs will look yellowy in none HID specific lamps/optics that's why it's recommended to go for something like a 5000k plus bulb. However, the futher you move up the Kelvin scale (the way the light output from HID's and other bulbs is measured), the more colour is added to the light. This will reduce the overall light output (measured in Lumens). A 4300k bulb will give you peak light output and so is idea (and why it's used by the OE manufacturers) but, the 5000k bulb will still give around 3 times the output of a normal 60w halogen bulb but, will have a whiter light in the sort of application we're looking at !
Hope that helps !
Let us know how you get on with these as, I'm very interested in buying a set myself !