I just put one 9003 bulb in my 2003 Mazda MPV and left the other bulb stock for comparison. The other bulb is original and 4 1/2 years old w/83,000 on the clock. While the light is whiter and maybe slightly brighter it really didn't seem to do much for me. I remember years ago getting the silverstars and they made a huge difference in my 95 truck. Are cars coming with better bulbs than they used to? I did a lot of reading here and other places before picking this bulb. Maybe the extremes are much better but I couldn't find those. I also have a set of 9006/9007 for my Suburban but haven't had the time to put them in yet.