I've noticed my OEM bulbs have the band on them, but most photos of aftermarket bulbs don't have them. What is it for, and is it necessary?

Thanks.

OEM, c/o Akinaboy auctions.


Aftermarket, c/o JD Lighting a.k.a Automax95

 

It's kinda of like a built-in shield.

D2R bulbs are for reflectors. The "shield" on the OEM bulb blocks some light in a reflector application to reduce some glare.

The aftermarket bulbs are really just D2S capsules that have the bases formed such that they can be placed in D2R or D2S housings. They're often referred to by the aftermarket as "D2C"

Personally, I'd spring for a set of OEM bulbs myself. Arc placement is usually better and their lifespan is usually better as well.

 

Ah, Thanks, J.

I also just noticed, with the light's on, the bottom part of the reflector doesn't really reflect much light compared to the top half. Have you noticed that on your I at all?

 

all OEM reflector hid setup are like that. the bottom half don't have much light down there that way light don't bounce off and cause more glare.

oh as for the oem bulbs with the shield...it's to block glare and make the cutoff more uniform when used in the oem reflector. i modified a pair of d2r bulbs (no shield) to use in my oem reflector housing and the cutoff was horrible. there was light shooting all over the place and the output was very crappy. it looked like i had an aftermarket hid kit on haha

 

Yeah it's weird how the majority of the aftermarket "D2R" bulbs don't have the shields on them.

I have a pair of OEM for sale w/ the shield removed if anyone is interested.

 

Yep, my I35 (before I retro'd TSX projectors) was like that. It's pretty much like lowincash stated - most OEM reflector setups are that way. Light hitting the bottom of the reflector bounces up and out of the headlight, creating glare above the cutoff.

 

Most after market are d2c is why. They have both cuts for d2r and d2s.