http://www.rallylights.com/hella/bulb_help.htm
I don't think you should waste your money on Silverstars....they don't last long and they are no brighter than the Hella 9003 bulbs I replaced my stock ones with...and payed half the price of silverstars for! (I have done side to side comparisons to Silverstars and other whiter colored bulbs)
if you compare a stock bulb to a silverstar of course a faded out stock bulb won't compare!
read thru the web site above(xenon section expesually) ...any white light bulb over 27% xenon gas is a waste of money unless you are using an HID bulb and system! compare a bulbs reflective light and not the head on appearance!
find a bulb with some % xenon and that has a L in the product code (for long life) of what ever brand... every automotive bulb I've seen with a color temp over 3000K also comes with a short or really short life...this side of HID
the 30% or 50% xenon Hella bulbs would be ideal if you want a "whiter" looking bulb (the site above has great prices but I have not personally bought from them as I bought locally before I did the research)...and if you want brighter you can get a bulb with more than 55 watts low beam and 60 watts high beam...but your wiring system will most likely not like anything over 85 watts from my experience...and less if you have after market lights on the stock wiring reliably.
I am plenty happy with 55/60 watt standard Hella 9003 bulbs light pattern and output, plus they match the output of the H3 bulb in the Micro DE lights I have with out frying my wiring harness...I don't know at what level(%) but they have some Xenon in them because they have a higher color temp than the stock Koito and other brand Halogen bulbs and appear to reflect light on the pavement that is whiter(more natural) than other halogen bulbs!!