You're screwing yourself if you put in Sylvania Silverstars or other bulbs like them. They produce *less* light, not more, and the light is *bluer*, not "whiter".

Here's manufacturer data, from internal engineering databases, for output and lifespan at 13.2v for H1 bulbs. The numbers here are a composite of values applicable to the products of the big three makers (Osram-Sylvania, Philips-Narva, Tungsram-GE). Each manufacturer's product in each category is slightly different but not significantly so. I picked H1-type bulbs for this comparison, and while the absolute numbers differ with different bulb types (9006, H7, H3, etc.), the relative comparison patterns hold good for whatever bulb type you consider. Lifespan is given as Tc, the hour figure at which 63.2 percent of the bulbs have failed.

H1 (regular normal): 1550 lumens, 650 hours

Long Life (or "HalogenPlus+") 1460 lumens, 1200 hours

Plus-30 High Efficacy (Osram Super, Sylvania Xtravision, Narva Rangepower, Candlepower Bright Light, Tungsram High Output, Philips Premium): 1700 lumens, 350 hours

Plus-50 Ultra High Efficacy (Philips VisionPlus, Osram Silverstar (but not Sylvania Silverstar despite the fact Osram bought Sylvania in the 1990s), Narva Rangepower+50, Tungsram Megalicht, 1750 lumens, 350 hours

Blue coated 'extra white' (Osram CoolBlue, Narva Rangepower Blue, Philips BlueVision, Tungsram Super Blue or EuroBlue, Sylvania Silverstar): 1380 lumens, 250 hours

Now, looking over these results, which one would you rather:

(a) Buy and drive with? (b) Sell?

The answer to (a) depends on how well you want to see versus how often to change the bulb. If you want the best possible seeing, you pick the Plus-50. If you don't care as long as it works and you don't want to hassle with it, you pick the long life.

The answer to (b) is determined by how rich your company's shareholders want you to be, and is obvious: You want to sell the bulb with the shortest lifespan, highest promotability and highest price. That'd be the blue unit, e.g. Sylvania Silverstar.

- Daniel Stern