Which color headlight is the safest? [closed]

Question

Ever since I upgraded to projector headlights I have been using 5000k xenon bulbs. The bulbs I am using are mediocre eBay bulbs and I have been giving some thought to nicer Philips or Morimoto bulbs.

If I decide to get nicer bulbs what color should I go with? I know that OEM bulbs are 4300k, but those look a little orange to me. The 5000k seem very white but not as white as some of my 6000k flashlights.

6000k should be the ideal color, but I always see that in those stupid "HID upgrade kits" that people put in Civics (no offense). I feel like there is a reason that dealers use 4300k, but 6000k really should show all of the colors on the road.

What is the safest?

Answer 1

The all of the "super white" headlights (which look blue-ish compared to normal headlights) are safety hazards for multiple reasons:

1. They have a much greater effect of blinding oncoming drivers -- and, if you have them adjusted improperly or use your hi-beams at inappropriate times, drivers in front of you two.

2. The "white" light produced by these headlights is not actually white (equal in all frequency components across the visible spectrum), but mostly concentrated at the red and blue ends of the spectrum. This means, for drivers like myself who wear high-power corrective lenses, the chromatic aberration is extremely serious. Instead of seeing a single white point or a slight blur, when we see your headlights out the edge of our lenses, we see one red point and one blue point, with the distance between them being greater than the width of the headlight. In other words, your headlights look like police lights!

Answer 2

I would have thought the amount of additional information you'd get from the whiter bulbs would be negligable compared to the difference between halogen and HID lamps, and I would suspect that the more orangey bulbs would cause slightly less glare than the whiter/bluer ones, and would therefore be safer. That's purely speculation though...

Answer 3

It could be argued that pure white (4000K) light is superior due to improved color rendition. But in reality, yellowish light (around 3200K) is probably the safest for night driving. Why?

First off, bluish light scatters in fog or poor weather and blue light has a very distracting effect to the human eye. Try to focus on a blue light at night and you'll realize that it's both difficult and uncomfortable. There's a reason why fog lamps on some vehicles is tinted yellow.

Second, any halogen bulb that tries to mimic a "xenon" headlamp has a color filter on the glass. This filter simply removes the yellowish part of the light output, which means fewer actual lumens are making it onto the road. Hence, it's providing an illusion of better visibility while actually providing less.

If you look up bulb specifications you'll find this to be the case. Bulbs with maximum output (most lumens) are unfiltered. These filaments are driven harder than regular bulbs so they produce more light with the same wattage. A byproduct is that they also burn hotter and have a slightly higher color temperature than normal bulbs (3500K). The consequence is a much shorter bulb life.

Tinted bulbs, such as Sylvania Silverstars, drive their filaments very hard to produce legal amounts of light. Their lumen output is the same as a cheap, standard bulb but with ridiculously short operating life (I think a 9005 bulb is rated at 50 hours!). I bet most of the tinted bulbs on eBay or whatever don't even put out the legally minimum amount.

Answer 4

I think safety only comes into play if you plan on speeding through the rain. If you live in southern California, it doesn't really matter. If you live in Seattle, maybe go with the 4000k so that you stand a chance of your headlights cutting through the rain. If I were you I would just stick with 5000k.