ECE standard (Europe & worldwide). Mercury-free HID (xenon) discharge bulb with PK32d-5 base and integral ignitor, for projector-type housings. 42V, 35W.
The Tesla Model S used two distinct headlight system types across the 2012-2018 model years: halogen capsule headlamps and HID headlamps. Each system requires a different bulb, and the two types are not interchangeable.
The 9005 is a single-filament halogen bulb operating at 12V and 65W, built to the ANSI standard used in the United States and Canada. It uses a P20d base and serves both the high beam and low beam positions in halogen-equipped Model S vehicles.
The D3S is a mercury-free HID xenon discharge bulb operating at 42V and 35W, built to the ECE standard used in Europe and worldwide. It uses a PK32d-5 base with an integral ignitor and is designed specifically for projector-type housings.
Because the D3S operates at 42V through a high-voltage ignition circuit, it is electrically incompatible with the 12V halogen system. Substituting one bulb type for the other is not supported by the specifications.
The D3S bulb incorporates an integral ignitor, meaning the ignition component is built directly into the bulb unit rather than housed separately within the vehicle. This is a defining characteristic of the D3S format within the HID bulb family.
The 9005 bulb is shared across both the high beam and low beam positions in halogen-equipped Model S vehicles, indicating a single-bulb-per-housing design rather than a separate bulb for each function.
The D3S similarly serves both the high beam and low beam positions in HID-equipped vehicles, consistent with projector-type housing designs that direct light output through optical means rather than through separate filaments or bulbs.
The halogen 9005 draws 65W compared to the HID D3S at 35W, reflecting the general characteristic of HID technology producing greater luminous output at lower wattage than halogen sources.