Guys, the thread started out asking about turn signal bulbs, not headlight bulbs. But yes, any of the blue *headlight* bulbs are for looks only, not increased light output. The best H4 bulbs you can get are the "Plus 50" types, either Philips Vision Plus or Osram SilverStar (NOTE that the "SilverStars" sold in North America are not +50's, they are different - stupid of them to use the same name in different countries for different products!) These +50 bulbs must be purchased from vendors in Europe like
www.powerbulbs.com or from one of the very rare US vendors who imports them like Dan Stern (
http://lighting.mbz.org or email:
dan@mbz.org). Here's some more reading:
http://www.peachparts.com/shopforum/showthread.php?threadid=50110
(note that the AutoExpress test has been deleted - d'oh!)
http://faq.auto.light.tripod.com/hl-filament-bulbs.htm
http://faq.auto.light.tripod.com/headlamp-faq.htm
Regards,