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- 2008 Mazda5 Touring
First, lumens at the bulb is not the same as lumens OTF (out the front), which is what translates to the candela used for FMVSS photometry judgements.
More importantly, the H11 filament is more compact than the MTG2 luminous die area. Based on some estimations (i.e. don't quote my numbers as fact), the luminous area of ONE MTG2 is about 40mm^2, and the luminous area of an H11 bulb is about 15mm^2. So the math says an H11 produces about 93lm/mm^2, compared to the MTG2's 45lm/mm^2.
The smaller, more concentrated "point source" of the halogen bulb filament (compared to the relatively large LED die) is what makes the halogen bulb have the correct beam pattern and higher candela. The lamp is specifically designed around not only the position of the filament, but its shape as well. While the LED bulb manufacturer can place the center of the LED unit at the same position as the halogen filament, the LED cannot duplicate the shape and luminous efficacy of the halogen.
I understand and agree.
What are your thoughts on the kits designed with Cree XM-L2 emitters? Much tighter luminous area as the die appears to be about 4mm^2, with up to 1054 theoretical lumens per.
http://www.cree.com/LED-Components-and-Modules/Products/XLamp/Discrete-Directional/XLamp-XML2
https://www.amazon.com/dp/ (commissions earned)