Originally Posted by Juha
I believe current systems at least are designed for 3w total. Quite often headlights sold for dynamos come with a 2,4w bulb as standard assuming you then hook up a 0,6w tail light to the system. If you do not, you will be better off replacing the 2,4w bulb with a 3w bulb.
This is correct. A total of 3W for all lights connected. That's usually 2.4W head + 0.6W tail or 3.0W head w/o tail.