Originally posted by randomtask77
Just out of curiosity, but are the bulbs of the 9003 and the H4 similar? They look the same (almost, but not absolutely sure) but I wanted to be positive if there are differences. If they are different, what car does use 9003 bulbs?
If I'm not mistaken, 9003 = H4. I remember when I was scrambling for bulbs for my stock headlights....I came across this quote from a site
A 9003 bulb can be replaced by an H4, made to industry standardsReplaces original bulb perfectly; however, may have a higher Wattage. H4 simply refers to the kind of bulb and base, not the headlamp unit. E-code refers to the headlamp unit that the bulb goes in. The light pattern is a combination of bulb type and headlamp reflector/lens. The Disco comes standard with H4 bulbs in a reflector that produces an e-code-like pattern with a sharp upper cutoff, yet has the U.S. aiming pips on the lens making them U.S. DOT approved.