glj12

Hi All,

In terms of brightness and light travel distance that aftermarket HID kits bring, is there any difference between the cheap brands or the expensive brands ($50 vs $150)? Is there any reason to opt for 55w over 35w? Also, is there a large different between halogen projectors (what all of these aftermarket products are geared for) and HID projectors?

Thanks!

Shimee

To answer your questions in order:

1. There is a huge difference in quality. The biggest factor is quality of construction. Higher end kits will have bulbs that are precisely assembled and ideally laser aligned for the arc chamber to be dead center to where the halogen filament would be. They will also use a metal cage or ceramic collar to secure the bulb in that position. Cheap kits are sloppy and the bulb is glued in place and not dead center. If the bulb is even slightly off from the focal point the brightness and distance will be severely affected. The quality of the ballasts and ignitors is also important because high end kits are made with better components, operate more stable, and are more reliable. A high end bulb will not produce the same color or intensity when powered with cheap ballasts/ignitors as opposed to high end ones.

2. The only reason to go 55w is for additional intensity. This is generally completely pointless with a high end 35w kit. The drawback to 55w is it shortens the lifespan of the bulbs because the bulbs are driven at higher power. Generally speaking HID bulbs are all the same and can be driven at 15w or 35w or 55w or 75w and so on. Whether it's a cheap kit or a high end one, they all use the same bulbs regardless of the drive power. But higher end bulbs are built with better material, to a higher standard, and can withstand the higher drive power better. It also generates more heat and UV which will shorten the lifespan of the reflector bowl. The higher output will also affect your down road visibility because since there is more light on the road immediately in front of the car, your eyes will adapt to let less light in and objects further away will appear darker.

3. There isn't that much difference between halogen and HID projectors but by no means are they the same. Fortunately the projectors that AL (Automotive Lighting, the manufacturer of the W204 headlights) uses in the halogen lights are very good and perform very well with HID kits. The main difference is the light source. On halogen bulbs it's a cylindrical wire with the most intense point at the center. On HID bulbs it's a crescent plasma arc with the most intense points at the ends, almost like two light sources. Each respective reflector is designed specifically around each light source so a halogen projector will have a different shaped bowl and lens compared to an HID projector. This is why the quality of HID bulb is so important. Higher end bulbs will position the plasma arc as close as physically possible to where the halogen filament would be. It's not ideal but much more forgiving than HID bulbs in halogen reflectors.

In short, cheap HID kits are good enough but a high end kit will be a much better investment. Don't repeat my mistake because I was once a fool that thought cheap HID kits were just as good as the expensive ones.

C300CA

Very, very well said Shimee. That is why they says the LED bulb will not be good in a halogen bulb projector housing; LED chip can't be placed in the center like halogen filament; the lens and bowl has to be designed specifically for LED I believe. I had H7 LEDs and tried in my halogen bulb housing. Result is terrible beam pattern with some dark spot.

I tried LED in my van with the reflector housing for halogen. Result is not great but I can accept it.

C300CA

Sorry I was off topic; it is about HID not LED.

Shimee

Those typical two-sided LED bulbs are TERRIBLE in projector headlights. Even the multi sided ones are terrible because the filament is no longer the same size so the focal point is ruined. The only LED bulbs that work remotely well in projector lights are the ones that light up at the tip. Like this:




In reflector lights the two-sided bulbs actually work pretty well because the LED chips recreate the shape of halogen filament. Also reflector lights are designed to utilize the light emitted to the sides of the halogen bulb whereas a projector utilizes the light emitted from all sides.