E38 Headlights HID or Halogen

[Xavier]

2001 740il headlights are ibelieve self leveling and HID.

I can barely see the road with the HID's on my car they are not bright enough
do these bulbs loose brightness with time?

I have a totaled 97 with Halogens, can swaped out the 01's with the 97?

Any ideas why they do not light up the road?

Thanks
Xavier

[psjr]

Are they aiming properly? If one of the leveling sensor arms is broken (quite common) the headlights could be pointing all the way up or all the way down and not hitting the road properly.

You will not be able to swap the 97s in.

[xboss]

That does not sound right. HID's are very bright. Do you have foggy lenses? Tons of dirt film & scratches can greatly reduce a headlights lighting ability.

[Raudi Driver]

You need to aim them. Pull up to a wall and dial them in. Make sure to keep your driver's side lower than your passenger side.

Follow this guide:
http://legacygt.com/forums/showthread.php/align-your-headlights-if-you-dont-know-now-you-do-54740.html?

[Haadkoe]

A couple other things to consider here:

Over time, hid lighting loses it's intensity. This happens very, very slowly, but the longer they're lit up the more the lumen output drops. If the bulbs in your housings are original to the car it is possible that they are not outputting as much light as they could be.

Also, the color of the light has a huge effect on visibility (especially when there is other traffic / light pollution). This is measured by Kelvin range. 3000k would be more of an amber, 6000 would be bright white like most newer BMW's, 8000k has more of a blue tinge, 10000k is even more blue, and 12000k is more purple.

The lower range bulbs in the 3000k neighborhood have a very similar color to traditional halogens, only brighter (Assuming the bulbs aren't terribly old). I believe this was the k range originally equipped in our cars... at least the ones in my car appeared to be that color, and based on output they had been in there for a while.

I find that bulbs in the 6000-8000 kelvin range light up the road with a color that is close to actual sunlight, and are quite resistant to light pollution.

10000k bulbs look great IMO, and when you're the only one on the road the reflected light is sufficient and contrast is good. Problem is, during situations where there is light pollution from oncoming traffic or overhead lighting that all tend to be in the lower more amber kelvin range, then the 10000k lights all but disappear.

I've never driven with 12000k or higher bulbs, but I've seen others with them on the road. Output looks dim and very very purple, almost like driving by blacklight. I can't imagine they're great for visibility.

At the end of the day, keep your bulbs fresh, and choose your kelvin range wisely IMO.

[TomInTX]

Thanks for the link about how to align the headlights Raudi Driver, it worked great.

[IamTitanium]

Here is a great reference with a color scale and some lumen outputs http://www.sharphid.com/category_s/137.htm