The Mercedes-Benz GLS450 uses D1S and H7 bulb sizes for both high beam and low beam headlight applications. The replacement chart covers 2017 to 2019 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 two bulb types specified across all headlight positions for the Mercedes-Benz GLS450 (2017-2019) are the D1S and H7, each corresponding to a distinct headlamp system installed at the factory.
The D1S is a high-intensity discharge (HID) xenon bulb rated at 85V and 35W, built to ECE standards for worldwide use. It features a PK32d-2 base with an integral ignitor and is designed specifically for projector-type housings.
The H7 is a single-filament halogen bulb rated at 12V and 55W, also conforming to ECE standards. It uses a PX26d base and carries approval for use in the United States and Japan in addition to European markets.
Both the high beam and low beam positions on the GLS450 (2017-2019) share the same bulb type within each headlamp configuration, meaning the D1S serves both functions in HID-equipped vehicles and the H7 serves both in halogen-equipped vehicles.
The D1S and H7 are not interchangeable. The D1S operates at a significantly higher voltage and requires an integrated ignitor and a projector housing, while the H7 is a conventional low-voltage halogen unit with a different base configuration.
Because the GLS450 was available with either HID or halogen headlamp assemblies during the 2017-2019 period, the correct bulb type is determined by the specific headlamp system installed on the vehicle, not by the model year alone.