Hi all,
Check out the great bulb tests at these URL's (one each for H1 and H7 bulbs, plus a separate test):
http://www.autoexpress.co.uk/product_test/product_test_story.php?id=10357
http://www.autoexpress.co.uk/product_test/product_test_story.php?id=10356
http://www.overboost.com/story.asp?id=102
To me, this was fascinating information. First, all "standard" bulbs are not created equal. I always thought all bulbs of a given wattage just put out "x" amount of light, normally measured in lumens. Well, that's generally true, but the pattern of output varies between bulb mfr's & brands! That was news to me. Also, the formal specifications for each bulb type (H1, H3, H4, etc) have a range - say, 1600 lumens, +/- 15%. Crappy bulbs (like the PIAA) may put out light at the bottom of that range (say, ~1350 lumens) and good bulbs will put out near the max (say, ~1750 lumens). The PIAA SuperWhites not only failed geometrically (output pattern), they drew more than the max allowable current (wattage), AND put out less than the legal limit for it's type (H1)!! Very sad. Also sad was the fact that some otherwise reputable mfr's bulbs were poor performers - notably Hella standard bulbs.
All the tests are for "stock" wattage bulbs. These are the ones you want to use if you lights are stock, or especially if you don't have relays installed. (If you have relays, AND E-code lights, then you can use high-wattage bulbs and get even more output. If you don't, high-wattage units either won't provide much improvment OR will blow fuses / melt connectors.) The "good" bulbs are the Phillips Vision Plus & Osram Silver Stars, which claim "50%" more light, and they really do perform well - at the top of bulb type (Hx) specs in all measurements. A couple of other brands also did very well, but they were oddballs we don't see over here in the States (at least I've never seen, or heard, of them before.) Also of note is that the "blue" bulbs do indeed put out less light than non-"blue" bulbs, regardless of how "white" their output may be. There's more informatin on this phenomenon at
http://lighting.mbz.org/
To buy these nifty bulbs, the only sources I've found are either Dan Stern, who you can contact at
dan@mbz.org , or you can order them from
www.powerbulbs.com (UK based, but they ship worldwide). Otherwise these bulbs are nearly impossible to locate in the USA. They're roughly $30-35 per pair, which isn't all that bad... especially since they put out a ton more light than the PIAA's, at less than half the cost!
For the record, I have Hella E-codes on my 123, and 500E Euro lights on both my 124's. I just installed relays on the one 124 and tried some high-wattage bulbs... and all I can say is, holy crap! It's damn near daylight on high beam with the driving lights on as well! The low beam is not as impressive as high, but still awesome. I highly recommend installing relays - with proper sized cables & fusing - if you have the expertise to do so. It's worth the effort (AFTER installing E-code lights, of course.) My voltage drop was roughly 1.0 volts at the bulb without relays, and dropped to 0.3 and 0.5 volts with relays and heavy cable (measured at the bulb, for low and high beam respectively.)
Just thought I'd share what I learned...
Oh, and a special thanks to Dan Stern for explaining some of the theory behind the operation of the various bulbs!
Regards,