Comatose

4300K = ~3200 lumens
6000K = ~2200 lumens

Its actually closer to 30% decrease in light output.

CrazyRuskie

iTrader: (3)

Where are you getting this information? Please provide a link for me.

Everywhere I look, the 6000k bulb produces 2900-3100 Lumens. Thats 5-10% decrease, nowhere near 30%

User 111021

iTrader: (2)

Thats crazy if you guys think that, I have both on 4 Cars, I cant even tell with my eyes the difference, but even if there was it would be at max 5-10%, 30% Sounds Extreme, Thats like bringing your lights down to Halogen Level

Comatose

FYI, halogens are typically rated at ~1000 lumens.
No one said theres a linear relationship to what your eyes can see/distinguish versus the amount of lumens a bulb puts out. Anything sitting 10ft infront of you of course you wont notice a difference, but where the difference is usually most noted are objects further away where light tapers off.

Anyway, I aint pulling these #'s out of my *** or anything, but pretty much every site I've seen seems to coincide.
e.g. http://http://faqlight.carpassion.info/hl-hid-bulbs.htm