GMC Burbalade
Busy slacking
While they don't cover everything, there are two threads already that go over HIDs, so I'll try not to overlap too much on the information provided there.
I have seen a LOT of misinformation out there in regards to both HID and LED headlights on topics that either aren't covered in the other topics or very little info is provided, so that's what I'm trying to go over here.
The absolute biggest misconception I see out there is that HIDs will always produce blinding glare in reflector housings, and that LEDs are a better choice in that aspect.
There are many people out there that will stand by this, many of which have never even used HIDs. Most of the time they will also tell you that HIDs but more light in the foreground causing them to look brighter, but less towards the cut off which hurts distance vision.
This is all 100% false. Let's look at some actual comparisons. These first two pictures are direct side by side comparisons of halogens and HIDs in halogen projectors.
You can see that the beam pattern is mostly unchanged with the change in light source. The biggest difference is in color and in light output, but you're got the same relative increase in distance and foreground lighting. The low quality beam pattern on the right is the result of a low quality projector/housing, it is not the result of running HIDs in a housing designed for halogens as evidenced by the fact that the the same housing produces the same pattern with the halogens it was designed for.
Now let's look at how LEDs perform is housings designed for halogens. The two images in this comparison were actually used in an advertisement for a drop in LED bulb.
Notice anything odd? The beam pattern with LEDs seems to have changed in the exact same matter that people claimed it would with HIDs when it didn't.
The "valley" in the middle means the beam is lower (and shorter) right in front of you, while the higher area to each side blinds drivers. There's a huge increase in foreground lighting but the middle of the beam has dropped, hurting distance vision and the hot spots in the beam pattern that act like spot lights to aid in distance vision straight ahead are now gone with the LEDs. This may look nicer, but it's an overall downgrade in lighting performance.
Now halogen vs LED in stock halogen reflector housings. Again, the first image here was used in an advertisement for a drop in LED.
Again we see a massive amount of foreground light with LEDs, with no real uopgrade in light output at the top of the pattern where you need it, along with a shift in the pattern itself and a major downgrade to the cut off, which is a big deal seeing as that sharp, bright cut off is what allows you to cast as much light down the road as you can without blinding other drivers.
It's well known that halogens, HIDs, and LEDs all produce light very differently. But the most important aspect in maintaining a safe beam pattern is not how the light is produced, but instead how the light is distributed. A filament and an arc distribute light in a very similar way, however LEDs are quite a bit different which is why we see this change in beam pattern. There are SOME drop in LED bulbs that produce a decent pattern in SOME housings, but this seems to be a small minority of cases.
Generally speaking, LEDs will be brighter than halogens, and HIDs will be brighter than LEDs. The brighter your lights are, the important it becomes to have a well designed housing to make the most use of that light were needed and control it where it isn't needed. In that regard, our factory headlights (and most OEM cut lens reflector headlights) just aren't up to the task of controlling HID light output.
The very first step you should take in upgrading your headlights is upgrading the housings and wiring.
If sticking to halogens, a simple relay harness in addition to wet sanding and clear coating an old yellowed lens can yield good results.
If you want LEDs, you should be looking into a complete replacement housing specifically designed for LED bulbs.
Perhaps the most confusing course of action is with HIDs. Yes, the "correct" way is retrofit quality HID projectors in an aftermarket clear lens housing. (NOT ebay projector housings) This will without a doubt provide the best possible beam pattern with HIDs. However, HIDs in a good quality clear lens reflector housing will often perform far better than stock lighting in both performance and beam control. I run HIDs in both my low beams and my aftermarket fog lights designed for halogens. Both produce great patterns with great output, thought neither were yet aligned in the below picture.
Though not in the same vehicle or same housing, here's an example of 100% stock headlights in a 1997 Ford F150. You'll have to excuse me for not having spare 9006 halogens on hand for a direct comparison in my housings, but as you can see the HIDs produce a better cutoff in aftermarket housings than halogens do in these stock housings.
Most vehicles that use HID low beams make use of bixenon projectors. In simpler terms, the same bulb is used for both high and low beams. The low beam is the same as the high beam with the top part of the beam "cut off" by a cut off shield. Since there's only one pair of bulbs used, there is no cut out or warm up time when switching from low to high beams or high to low.
You can achieve this same thing if you choose to retrofit bixenon projectors. If you go a different route, you can use the 4high mod which keeps the low beams on when the high beams are used. That way you don't have to wait for your low beams to warm up when switching from high to low, and if you've got HID high beams, you will at least still have your low beams on while the high beams warm up. This is covered in other threads so I wont go into the installation process but I will say that it should NOT be done without at least one relay.
If you use your high beams to flash people or use them on/off regularly, you'll probably want to skip HID high beams. Many people including myself prefer to run HID low beams with halogen high beams. This way there's no warm up time for the high beams, and when used with 4high the ONLY warm up time you need is when you start the vehicle.
Many people upgrade to HIDs for the wrong reasons. If you're doing it because you want blue, pink, red, green, etc. headlights on a daily driven vehicle, then yes. That means you. Those colors are fine for shows but please keep them off of public roads. If you want blue headlights because you want it to look like a newer vehicle with factory, HIDs, then you really don't want blue headlights. What you're seeing on newer vehicles is the small amount of blue light above the cut off as shown below. The beam pattern itself on these vehicles is white, usually 4000-4300k.
It's with good reason that factory lights don't have blue within the pattern. Primarily because it's illegal, and you simply don't see as well in blue light. Additionally, blue light causes more glare and the more color your HIDs produce, the less useful light they produce. Nearly every aspect of blue light is a disadvantage in a headlight.
"But I see fine with blue light"
Not as well as you think. It looks just as bright, but your ability to make out objects and contrast is severely hindered. Even the blue coated halogen "high end" lights put out less light than low end halogens as they're only achieving that whiter output by filtering out the more useful wavelengths.
If you're dead set on wanting some blue in your headlights, I would recommend 5000k, though anything 6000k or below is generally considered reasonable.
While the legality of lighting sources for headlights is a gray area, the legality of headlight colors is not. It's quite clearly defined in U.S. Federal Safety Standards. Yes, Federal. That means you can't use being in a different state as an excuse. The area labelled "white" is what's legal for headlights. It does reach well into the yellow spectrum but you can clearly see there's no hint of blue, red, or green permitted. The below image is an official color definitions chart laid over a color chart that actually shows the color, to give you a better idea of exactly what those definitions are.
Pure white is around 4300k, this is what most OEMs use and it's what gives you the most light. Below that and light becomes more yellow and then orange and red. Above that, light becomes teal and then blue.
For more resources or info, check out:
The Retrofit Source
FMVSS 108
I have seen a LOT of misinformation out there in regards to both HID and LED headlights on topics that either aren't covered in the other topics or very little info is provided, so that's what I'm trying to go over here.
Part I: Lighting Sources
The absolute biggest misconception I see out there is that HIDs will always produce blinding glare in reflector housings, and that LEDs are a better choice in that aspect.
There are many people out there that will stand by this, many of which have never even used HIDs. Most of the time they will also tell you that HIDs but more light in the foreground causing them to look brighter, but less towards the cut off which hurts distance vision.
This is all 100% false. Let's look at some actual comparisons. These first two pictures are direct side by side comparisons of halogens and HIDs in halogen projectors.
You must be registered for see images attach
You must be registered for see images attach
You can see that the beam pattern is mostly unchanged with the change in light source. The biggest difference is in color and in light output, but you're got the same relative increase in distance and foreground lighting. The low quality beam pattern on the right is the result of a low quality projector/housing, it is not the result of running HIDs in a housing designed for halogens as evidenced by the fact that the the same housing produces the same pattern with the halogens it was designed for.
Now let's look at how LEDs perform is housings designed for halogens. The two images in this comparison were actually used in an advertisement for a drop in LED bulb.
You must be registered for see images attach
Notice anything odd? The beam pattern with LEDs seems to have changed in the exact same matter that people claimed it would with HIDs when it didn't.
The "valley" in the middle means the beam is lower (and shorter) right in front of you, while the higher area to each side blinds drivers. There's a huge increase in foreground lighting but the middle of the beam has dropped, hurting distance vision and the hot spots in the beam pattern that act like spot lights to aid in distance vision straight ahead are now gone with the LEDs. This may look nicer, but it's an overall downgrade in lighting performance.
Now halogen vs LED in stock halogen reflector housings. Again, the first image here was used in an advertisement for a drop in LED.
You must be registered for see images attach
You must be registered for see images attach
Again we see a massive amount of foreground light with LEDs, with no real uopgrade in light output at the top of the pattern where you need it, along with a shift in the pattern itself and a major downgrade to the cut off, which is a big deal seeing as that sharp, bright cut off is what allows you to cast as much light down the road as you can without blinding other drivers.
It's well known that halogens, HIDs, and LEDs all produce light very differently. But the most important aspect in maintaining a safe beam pattern is not how the light is produced, but instead how the light is distributed. A filament and an arc distribute light in a very similar way, however LEDs are quite a bit different which is why we see this change in beam pattern. There are SOME drop in LED bulbs that produce a decent pattern in SOME housings, but this seems to be a small minority of cases.
Generally speaking, LEDs will be brighter than halogens, and HIDs will be brighter than LEDs. The brighter your lights are, the important it becomes to have a well designed housing to make the most use of that light were needed and control it where it isn't needed. In that regard, our factory headlights (and most OEM cut lens reflector headlights) just aren't up to the task of controlling HID light output.
The very first step you should take in upgrading your headlights is upgrading the housings and wiring.
If sticking to halogens, a simple relay harness in addition to wet sanding and clear coating an old yellowed lens can yield good results.
If you want LEDs, you should be looking into a complete replacement housing specifically designed for LED bulbs.
Perhaps the most confusing course of action is with HIDs. Yes, the "correct" way is retrofit quality HID projectors in an aftermarket clear lens housing. (NOT ebay projector housings) This will without a doubt provide the best possible beam pattern with HIDs. However, HIDs in a good quality clear lens reflector housing will often perform far better than stock lighting in both performance and beam control. I run HIDs in both my low beams and my aftermarket fog lights designed for halogens. Both produce great patterns with great output, thought neither were yet aligned in the below picture.
You must be registered for see images attach
Though not in the same vehicle or same housing, here's an example of 100% stock headlights in a 1997 Ford F150. You'll have to excuse me for not having spare 9006 halogens on hand for a direct comparison in my housings, but as you can see the HIDs produce a better cutoff in aftermarket housings than halogens do in these stock housings.
You must be registered for see images attach
Part II: High Beams
Most vehicles that use HID low beams make use of bixenon projectors. In simpler terms, the same bulb is used for both high and low beams. The low beam is the same as the high beam with the top part of the beam "cut off" by a cut off shield. Since there's only one pair of bulbs used, there is no cut out or warm up time when switching from low to high beams or high to low.
You can achieve this same thing if you choose to retrofit bixenon projectors. If you go a different route, you can use the 4high mod which keeps the low beams on when the high beams are used. That way you don't have to wait for your low beams to warm up when switching from high to low, and if you've got HID high beams, you will at least still have your low beams on while the high beams warm up. This is covered in other threads so I wont go into the installation process but I will say that it should NOT be done without at least one relay.
If you use your high beams to flash people or use them on/off regularly, you'll probably want to skip HID high beams. Many people including myself prefer to run HID low beams with halogen high beams. This way there's no warm up time for the high beams, and when used with 4high the ONLY warm up time you need is when you start the vehicle.
Part III: Color
Many people upgrade to HIDs for the wrong reasons. If you're doing it because you want blue, pink, red, green, etc. headlights on a daily driven vehicle, then yes. That means you. Those colors are fine for shows but please keep them off of public roads. If you want blue headlights because you want it to look like a newer vehicle with factory, HIDs, then you really don't want blue headlights. What you're seeing on newer vehicles is the small amount of blue light above the cut off as shown below. The beam pattern itself on these vehicles is white, usually 4000-4300k.
You must be registered for see images attach
It's with good reason that factory lights don't have blue within the pattern. Primarily because it's illegal, and you simply don't see as well in blue light. Additionally, blue light causes more glare and the more color your HIDs produce, the less useful light they produce. Nearly every aspect of blue light is a disadvantage in a headlight.
"But I see fine with blue light"
Not as well as you think. It looks just as bright, but your ability to make out objects and contrast is severely hindered. Even the blue coated halogen "high end" lights put out less light than low end halogens as they're only achieving that whiter output by filtering out the more useful wavelengths.
If you're dead set on wanting some blue in your headlights, I would recommend 5000k, though anything 6000k or below is generally considered reasonable.
You must be registered for see images attach
While the legality of lighting sources for headlights is a gray area, the legality of headlight colors is not. It's quite clearly defined in U.S. Federal Safety Standards. Yes, Federal. That means you can't use being in a different state as an excuse. The area labelled "white" is what's legal for headlights. It does reach well into the yellow spectrum but you can clearly see there's no hint of blue, red, or green permitted. The below image is an official color definitions chart laid over a color chart that actually shows the color, to give you a better idea of exactly what those definitions are.
You must be registered for see images attach
Pure white is around 4300k, this is what most OEMs use and it's what gives you the most light. Below that and light becomes more yellow and then orange and red. Above that, light becomes teal and then blue.
You must be registered for see images
For more resources or info, check out:
The Retrofit Source
FMVSS 108
Last edited:
