Originally Posted by
noglider
[MENTION=73614]rhm[/MENTION]'s point seems to be that a modern LED headlight might not start producing good light until the power (wattage) reaches a certain point.
No. A lamp made for an incandescent bulb has a parabolic reflector that directs the light where you want it. if you replace that bulb with a different light source, even if it's more powerful (which an LED probably is), if the light source is not at the focal point of the reflector you will get less light where you want it.