jbeech

Is there any difference in the lens itself between an HID (Xenon) and a halogen headlamp assembly? Like, are the HID a different kind of plastic lens, or thickness? I wonder because the headlamps in our 2005 C320 station wagon have yellowed while with our 2004 E320, which has HID lamps, they have not developed those unattractive cataracts, e.g. yellowed.

My neighbor also has a 2004 E320 but with halogen headlamps (his is a sedan while mine is a wagon) and he says he's had his lamps resurfaced as well. Since all three cars live outdoors, I'm wondering why has our E320 never needed to have the lens surface re-polished? What's different?

NewShockerGuy

Depends on the elements and how much UV is hitting the lenses. Manufactures coat the lenses in UV coating to prevent this from happening quickly and turning yellow... it will vary greatly depending on where the car is at.


IE: Why you normally see cars that are always exposed to sun having their clear coats peeling or yellow headlights.


This will also happen quicker if one polishes their headlights because they are in essence taking the coating off.


Some headlights will develop this from the inside if someone is using crappy bulbs. Bulbs put out UV and over time the lense can one take so much before it starts to break down.


I've taken both of the lenses apart from our car to do an hid projector retrofit, and a true oem hid headlight. Lenses were identical.


-Nigel