http://forums.genvibe.com/zerothread?id=38452 http://forums.genvibe.com/zerothread?id=31075I'll just leave those there. Pics may be gone in some posts but the basice jist is this:-Silverstars are rated for 300 hours of life. Your typical OEM halogen is rated for 1000 hours.-Silverstar Ultras are rated for about 450-500 hours, slightly better but still less than standard halogen.-Silverstars as with most other aftermarket novelty bulbs are rated in Kelvin. Kelvin is a scale used to determine temperature by color. An HID bulb for a factory car is typically in the 4100-4300 scale of Kelvin which is considered "daylight". Anything lower is more yellow (3000-3500K) for fog lamps in some applications, and anything higher 4000, 6000, 8000+ gets more blue and then purple and if your nuts, 13000K for pink. Aftermarket companies rate the HID kits as Kelvin temps to appeal to buyers looking for color. All HID's that are standard equip. on a car only appear to have color differences because the projector lens is coated and shaped to throw different light output in different areas.-Lumens is the TRUE scale for measuring "light output". I'm not sure if I cover the Lumen output in those posts above but it breaks down to if you coat the bulb with any kind of color filament, you are losing light output. Even Silverstars have a slight bluish coating to produce a more "white" light that "appears brighter". But in actuality it is decreasing the light output of a good brand halogen. -There is a difference between $2 Walmart bulbs and a name brand like GE, Phillips, etc.-The HIR bulb is Halogen Infra-red, it has a reflective coating (not colored) that reflects IR light back onto the filament causing it to glow/burn hotter and produce more light without using more power. Think of bulbs that advertise for 80W, 120W, 150W. Your car is designed to operate with 50-65W resepctively when it comes to halogen lamps. Anything over this may potentially be hazardous and can cause premature bulb loss, frying of the cars headlamp wiring, and other electrical issues.-The HIR bulb was designed by GE by request of John Deere to produce a bulb with 80% of the output of an HID without the added cost. Back then HID's cost close to $1,000 for an aftermarket kit. Again we are talking farm equipment with sealed beam HID's, not Ebay kits for your car. GE sold the tech to Toshiba who then created a plug in HIR bulb with a bulbous shape instead of a capsule. It was sold through JD parts dealers for approx. $9 a bulb. Keep in mind the HIR bulb first appeared on the first generation Dodge Viper at a cost of $150 a bulb. Word got out in the aftermarket community of this bulb from JD and soon JD got smart and prices went up from $9 to $12 and now $20+ a bulb. The advantage being you get more light output than a standard halogen, less cost than an HID, and long life. The tradeoff is the bulb was only available in 9012 and 9011 sizes. These relate to 9006 and 9005 (slight modification to the holding tabs of plastic required to fit), but it left many others with 9003 styles and others out of the picture.-Toshiba's patent ran out on the HIR technology and now Phillips has created a bulb known as the X-Treme which is even better than an HIR bulb as it is more reliable and requires no modification of the bulb housing to fit. And it comes in many sizes for everyone to enjoy. To date it is the best halogen light bulb on the market.-Unless you retrofit your lamp for HID projectors or buy old Acura headlights for HID bulbs then you are not going to achieve much brighter results. It is more appearance as you lose a lot to glare than to actual light output. Retrofitting a projector lens allows proper light output but is expensive. HID bulbs are offered in two different types, D2S and D2R (projector and reflective styles). One for a projector lens and the other for non. But you will see pretty much all new cars with HID's utilize projectors.OK I have put in enough for now, happy reading!