Originally posted by see_fu
It depends on the manufacture. I just got some Mcculloch bulbs and their 8000k bulb is claiming to be 3000 lumens while their 4700k bulb claims to be 3700 lumens. To give you a comparison, 4300k philips is around 3000 lumens too. I have no clue if the numbers Mcculloch numbers are exaggerated, but that's just what they gave me
Llumens do not matter in the usable light put down on the road. color tempature is what matters. 4300K is equivalent to daylight and the human eye see the light on the road the best at this wavelength