I've spent some time on this forum, and if there's one thing I see come up time and time again, it's the conversation around the bulbs in your headlights. It's really a quite simple concept, but there's a lot of misconception around it that we'll clear up here.
As we all know, our cars come with two types of headlights: projector-based halogen H11s, and projector-based HID D4S bulbs. Your car comes with one or the other, and they are not interchangeable.
If your car comes with a halogen H11 bulb, you have three options for upgrading: an H9 retrofit
, or a Philips Xtreme Vision H11
, or an HID projector retrofit
If your car comes with an HID D4S bulb, one upgrade option is the Osram CBI D4S
If you've read this far, this is all you need to know. If you're still unsure, continue reading.
Before we start, HID kits in non HID headlights are illegal, per United States DOT. If you don't know how HID bulbs and kits work, read here
Many people throw "HID kits" into their halogen projectors, looking for an upgrade. Usually
this isn't a "bad" idea, per se, but it's not a great one either. Halogen bulbs and HID bulbs are shaped differently, everyone knows that. What that means, is that when shaped differently, they project light differently. The bulbs all have their own patterns, and the projectors (or reflectors, but those aren't applicable in our cars) are shaped around the bulbs in order to give the best output
. This can be clearly seen when some HID bulbs project a "shadow" on their light pattern; it's due to one of the components of the bulb getting in the way of where the light is supposed to go. The problem with HID kits in a halogen projector is inherent in their design: not all possible light is being utilized.
Furthermore, all projectors are designed with something called "squirrel spotters." They don't actually spot squirrels though. What they do is allow a very
small amount of light out above the beam cutoff to illuminate road signs, traffic light signs, and other highway signs. This creates a minor, but acceptable glare to other drivers. When you put an HID bulb in a Halogen projector, you might be adding "more" light. That extra light has to go somewhere, and it's going two places: everywhere in the projector, and through the squirrel spotters. In layman's terms? You're increasing the glare from your projector to oncoming drivers. This is rude.
Now, I did just say that HIDs produce "more" light - they do, in the right application. If your projector isn't designed for it, you can't use that extra light. It's being wasted bouncing around your projector, hitting your cutoff shield, hitting the wrong part of the ground, or blinding other drivers. Lastly, proper HID setups have evenly distributed light and wide beams. Halogens don't produce as much light, so the beam has to be more focused in order to get distance. An HID bulb in a halogen projector doesn't utilize all of the light, and in some cases, can misplace it. See below for a visual.
HIDs come typically in "35 watts" or "50/55 watts." Most kits in cars from OEM or otherwise run at 35 watts. The bulbs don't burn as hot and don't take as much energy. If you're going to ignore everything in this post and install HIDs in your halogen projectors anyways because of "muh white light," then do 35 watt so you don't burn your car to the ground - or at least melt your projectors. Everyone's touched a hot light bulb. Imagine something hotter, sitting in an enclosed projector, for an extended amount of time. Something will give. Additionally, as one would expect, a 35w or 55w HID kit draws more power, which isn't something your stock wiring will provide.
An example of a proper cutoff for halogen bulbs and HID bulbs is seen here:
Everyone likes to talk about LED bulbs. They're low power, super bright, cheap, and all kinds of colors. Truly, they're great. And they are - in the proper application. I have LED bulbs in my interior dome lights - much brighter, yes, compared to what we started with. That's where it stops, however. Recall how we discussed that HID bulbs and halogen bulbs are shaped differently, and therefore throw light differently? This also applies to LED bulbs - even if the chips are all around the bulb and they have fancy projector caps. No LED bulb is as bright as the halogen bulb you're trying to replace. This I can promise you. While it might be "super bright and white," you'll have no throw, no width, no cutoff, and no effectiveness. Refer to the photo below.
On color temperature:
Color temperature is how "yellow" or "white" your bulbs will be, measured in Kelvin (K). Yellow bulbs are 3000k, regular headlights are usually 4000k, OEM HIDs are 4300-4500k, white is 5000k, and white-blue is 6000k. As you go up in Kelvin, you tend to lose brightness. Optimal color temperature is 4300k-5000k in most applications.
That's all I have, and all you need to know. Your bulb upgrade path is above. I welcome discussion in this thread and am happy to update the OP, of course. But if you're going to post about "muh HIDeez" in your halogen projector, back it up with comparison shots against a wall, at night, 25 feet away, with a locked exposure on your camera. Your phone pictures won't cut it. Discussion should be scientific and fact based, not anecdotal.
Lastly, aftermarket headlights are all garbage and need their projectors replaced.
And for the love of God, stop tinting your headlights and taillights.