The Ford GT high beam and low beam headlight bulbs both utilize the D1S size. The replacement chart covers 2005 to 2006 vehicle production specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The D1S is a high-intensity discharge (HID) bulb that operates on xenon gas. It runs at 85 volts and 35 watts, which places it in a significantly higher voltage range than conventional halogen bulbs.
The D1S bulb follows the ECE standard, meaning it is recognized for use in Europe and other markets that adopt ECE lighting regulations. This standard governs light output, beam pattern, and color temperature for road use.
A defining characteristic of the D1S is its integral ignitor, which is built directly into the bulb unit rather than housed separately in the vehicle's ballast system. This design makes the ignitor and bulb a single replaceable assembly.
The D1S uses a PK32d-2 base, a keyed connector format specific to this bulb family. The keyed design physically prevents incorrect bulb installation, as incompatible base types will not seat in a D1S socket.
The D1S is engineered exclusively for projector-type headlight housings. Projector housings use a lens and reflector system that controls the beam pattern precisely, and the D1S is not interchangeable with reflector-type housings without significant optical consequences.
The Ford GT (2005-2006) uses the D1S bulb for both the high beam and low beam headlight positions. In projector-based HID systems, a single bulb type commonly serves both functions through shutter mechanisms within the housing rather than separate bulb units.