The Porsche Carrera GT high beam headlight requires a 9005XS bulb size while the low beam headlight uses a D1S bulb size. The replacement chart covers 2004 to 2005 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Porsche Carrera GT uses the 9005XS bulb for high beam headlights across both the 2004-2005 model years. This bulb follows the ANSI standard applicable in the US and Canada, operates at 12V and 65W, and features a single filament with a straight 180-degree base orientation.
The 9005XS is a variant of the broader 9005 family. The "XS" designation indicates the straight base configuration, which differs physically from other base angles found in related bulb types, making cross-substitution with non-XS variants a fitment concern.
Low beam headlights on the 2004-2005 Carrera GT use the D1S bulb, an HID (high-intensity discharge) xenon type that operates at 85V and 35W. Unlike halogen bulbs, HID bulbs produce light through an electrical arc between tungsten electrodes within a xenon gas-filled quartz capsule rather than through a heated filament.
The D1S bulb conforms to the ECE standard, which governs lighting equipment across Europe and many other markets worldwide. Its base type is PK32d-2, and the bulb incorporates an integral ignitor, meaning the high-voltage starting component is built directly into the bulb unit itself.
Because the D1S includes an integrated ignitor, it is not interchangeable with D2S bulbs, which require a separate external ignitor housed within the ballast or fixture. Substituting one for the other is electrically and physically incompatible.
The Carrera GT therefore runs a mixed lighting system, pairing a halogen high beam with an HID low beam. These two bulb types operate on fundamentally different electrical principles and voltage levels, and their respective circuits are not interchangeable.
The D1S is specified for projector-type housings, which use a lens and cutoff shield to shape and direct the light output. This housing requirement is part of the bulb's design intent, as HID sources have different optical characteristics compared to halogen filaments.