Can a 9003 bulb be used in place of a HB4? My dad has a 96 LS4, and wants to try the Philips NIghtguide bulbs, but according to Philips, only come in 9003, 9004, 9005, 9006, 9007, and H7. Since I've read that 9003 is like HB4, can he use that bulb instead? What complications would there be?

 

I thought HB4 is equivalent to 9006, not 9003? I may be wrong so correct me please if needed.

-tc

 

HB4=9006

im assuming your dad has wants to replace the lows, in which case hes going to need an H4 bulb, not an HB4. HB4's are used in the fogs.

9003=H4 this is a dual filament meaning that your lows are on when ur highs are on.

http://www.sylvania.com/ConsumerProd...lacementGuide/

 

PureDrifter is correct, the bulb you're lookin' for is 9003 aka H4.