This is probably a DS question or rather answer.
I just looked up the specs for Sylvania bulbs for the 9004 series using:
And the wattage is identical for all the bulbs.
But the hours vary wildly.
Now take the XtraVision. Since the output in lumens is the same, I gather it delivers, somehow, more light in the visible light spectrum than the ordinary 9004? And/or does it deliver somehow a wider arc of light?
The only thing that varies even slight among all these bulbs is the MSCD. What does the MSCD mean? But it's mostly the same, almost the same, for all these bulbs by Sylvania, whether regular, XtraVision, Cool Blue, or even Silver Star. Can't get over that the specs are the same for lumens and wattage.
Since the 9004LL is 850 hours on low beams versus 320 hours on the regular 9004, this would appear to be a good buy if one just wants a bulb that will last more than twice as long on low beam. On high beam, it's 250 versus 150, not even twice as long. The XtraVision 9004XV is
220 hours on low but 145 hours on high, so almost the same as the ordinary 9004 but clearly less than the 9004LL.I noticed that DS recommended the XtraVision as a little better. Is it because it is wider and throws more light in the best part of the human's visible spectrum while the actual lumens and wattage remains the same? I have noticed that in the visible spectrum, red light will not show as much as green light because the human eye is far more sensitive to green light.
I don't understand how a bulb can have the identical lumens and wattage but be so much better that it costs 4x as much. And lasts 1/4 as long. I'm curious. Comparing the Silver Star to the Long Life, one gets this unusual comparison.