There are numerous variables which are factors in this result. Chief among them are the differences between ECE and NHTSA requirements. ECE has a separate standard and measurement values for each type of light source (Halogen, HID, LED, and Laser) which uses and aggregate total of points for a maximum total luminance.
NHTSA (DOT) uses multiple points, but non-aggregate total, leaving only one point as the limiting (maximum) value. So the US/SAE lamps are de-rated and re-aligned to stay within the limit of the single maximum point value. This also affects Halogen and HID, but LED's are de-rated more than the others.
I made this partial illustration of an F10 with the de-rating removed. It has a few small errors due to differences between models and not all lighting modes are represented. For the US, only modes M1 (Foul Weather with Front Fog Lamps on), M5, and M15 are active. RoW gives additional modes of various combinations of aiming and intensity. The file is a vector so zoom in as much as one wants. Black represents 0% Illimination, White is 98% (max rated luminous output is based on 13v but supply power is 13.8v), and the various grey tones represent the various intensities of the LED arrays in their operating modes.
https://drive.google.com/open?id=0B9...jZmckFOM2FjaWM