Sylvania Silverstars for a PT

replace both the Hi and Lo beams? I see on > the Sylvania site that the newest bright bulb's they have, the Ultra's are not available for my 2005 GT as of yet.

Yeah, they'll make a significant difference, but not in the direction you think. All of these blue-glass "extra white" bulbs are a scam.

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, 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, Narva Rangepower+50, Tungsram Megalicht, but not Sylvania Silverstar):

1750 lumens, 350 hours

Blue coated 'extra white' (Osram CoolBlue, Narva Rangepower Blue, Philips BlueVision or CrystalVision, Tungsram Super Blue or EuroBlue, Sylvania Silverstar or Silverstar Ultra, which is just a rebrand of the Silverstar product, also PIAA, Hoen, Nokya, Polarg, etc):

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.

Unfortunately for your present needs, there are no +30 or +50 bulbs in the straight-base 9005XS and 9006XS bulb type your PT Cruiser takes. The best bulb available is the regular normal one.