HID lighting is a vast subject. We will try and explore some of the myths in this small article.
Hopefully this will give you the information you require, which will make you understand why we do not sell the cheapest eBay quality kits!
One thing for sure is that the light output of HID systems is massively superior... Below is a picture of them side by side. On the left is a 100W H7 bulb (technically not legal in the UK) and on the right is a 35W HID.
There are several important issues with HID systems - Quality of the ballasts, quality of the lamps, wattage and heat range (also known as brightness, measured in K).
HID lights don't work like conventional bulbs where a metal filament glows in an inert gas - HID uses a pair of metal plates with gas between them and the electricity jumps the gap (like a spark plug) and is kept alight by the massive voltage from the ballast.
Quality of the Ballasts
The Ballast is the small box that takes the low level 12v input which goes to the normal headlight and boosts it up to very high voltage to make the lamps (bulbs) light up.
Ballast quality varies massively, but generally they are categorised in one of 4 levels.
Level 1 - Parts are held to the best quality control. Ballasts use larger capacitors and are potted. They are matched in pairs for consistent output
Level 2 - Parts tend to use medium sized capacitors and are also potted. They are matched to within a reasonable tolerance. These would be the lowest quality items we would sell, but as yet do not stock them. Typically about 8-10% cheaper than level 1.
Level 3 - Parts are the lowest that we would consider even mentioning! Ballasts are not potted, capacitor sizes are large enough to work properly as a plug-and-play setup on most cars, but not all. Ballasts are not matched in pairs at all. Two are just taken from the production line and packaged. Typically this is what you would buy from eBay for around £39 + postage. Failure rate on ballasts seems quite high.
Quality of the lamps
Again, massive variance in quality. High level bulbs can be considered plug and play in terms of fitment and operation. Lower levels... not so much!
Level 1 - The bulbs are held to the best quality control. Bulbs are held to the tightest tolerances and exceed OEM quality. They are matched in pairs for consistent output.
Level 2 - The bulbs are held to slightler looser tolerances than level 1. Around or slightly below OEM specification.
Level 3 - The bulbs are not colour controlled. They tend to match from batch-to-batch but that's it. Well below OEM specification. These could only be considered an upgrade if you want the HID "look". Not a performance upgrade - in fact you would probably see more with a high quality Halogen bulb!
So you can see that there are a great number of combinations of Ballast and Lamp. We only supply Level 1 Ballasts and Bulbs. We emphasise performance, not "larging it up in B+Q or Maccy-D's Car Parks".
HID lights come in 2 main wattages - 35w and 50w. The 35w is very very bright! The 50w should only be considered if you drive on very poor roads and in bad conditions on a regular basis. There is no point in having the 55w version if you drive mainly in towns and on major A-roads.
They cannot be compared to Halogen Bulb wattages. Rough equivalent of the 35w HID is 110w in Halogen. 55w in HID is approximately 150-160w in Halogen!
The 35w version will - 99.9% of the time - not need any changes to OEM wiring. The 55w version *may* need you to upgrade your wiring. On modern cars this is usually not the case though.
The other thing to bear in mind with the higher wattage bulbs is that they generate a lot of heat, so if you have thin plastic lenses on your headlights, then these can become distorted.
HID light output is much brighter than a conventional halogen system. It is measured in heat ranges - typically 4000K, 5000K, 6000K, 7000K, 8000K, 9000K, 10000K and so on. The highest heat range is 30,000K, but the light output from this is terrible! The heat range basically indicates the colour of the light.
The closest output to a white light, which gives the best vision, is between 6000K and 7000K. Lower than 6000K the light tends to become more yellow and higher than 8000K the light tends to become more purple.
Currently we stock 6000K due to this being the best compromise of "looks" and actual real world performance. We do intend to stock 8000K units as well - which give the "blue" look that some people desire. We must stress that in real world conditions the 8000K units are no better than 6000K.
Hopefully this has cleared up some of the myths that surround HID units, and you can see why we choose the Level 1 kits in 6000K colour.
Don't be fooled into buying the cheapest Chinese kit on eBay by claims that they are a massive upgrade! We have spent over a year now testing lighting kits before offering them for sale to our customers.
If you have any further questions or would like some advice about HID lighting - please do not hesitate to contact us on firstname.lastname@example.org