idk if this is a stupid question but 03 fogs are h4 bulbs and 06 fogs are h1 bulbs but would h1 bulbs fit if its suppose to be a h4 bulb and visversa

 

The bulbs may be interchangable, but the H4 is a dual purpose bulb...its both a fog light and your high beam. The H1 is strictly a fog......
So, if your planning on installing them in an 03-05 headlight, your going to lose your highbeam function.

 

alright thanks. much help

 

Good thing I read this...I wasn't sure about this either. So even though I have the 06 projector headlights, I still need to purchase the H4 bulb for replacement fog/high beam lights.

 

Negative, u need to buy H1 bulbs.