The Mercedes-Benz SL400 high beam and low beam headlight bulbs both utilize a D1S bulb size. The replacement chart covers 2015 to 2016 model 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 D1S is the sole bulb type specified for the Mercedes-Benz SL400, covering both the high beam and low beam headlight positions across the 2015-2016 model years.
D1S is a High-Intensity Discharge (HID) xenon bulb, meaning it produces light by passing an electrical arc through xenon gas rather than heating a filament. It operates at 85 volts and 35 watts.
The bulb carries a PK32d-2 base and includes an integral ignitor, meaning the ignition component is built directly into the bulb unit rather than housed separately in the vehicle's ballast system.
D1S bulbs are designed exclusively for projector-type headlight housings, which use a lens and reflector assembly to focus the light output into a controlled beam pattern.
The D1S standard falls under ECE (Economic Commission for Europe) regulation, indicating it is approved for use in Europe and other markets that follow ECE lighting standards.
Because the ignitor is integrated into the D1S bulb itself, substituting a bulb type with a separate ignitor arrangement would not be compatible with the SL400's headlight housing design.