The Mercedes-Benz GL450 headlight bulb specifications include D1S, H7, and D2S sizes for high and low beam applications. A replacement chart documents bulb size data spanning 2007 to 2016 model years.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The H7 is a single-filament halogen bulb operating at 12V and 55W, built to ECE standards and also approved for use in the United States and Japan. It uses a PX26d base and serves both high and low beam positions across the Mercedes-Benz GL450 lineup.
The D1S is an HID (xenon) discharge bulb rated at 85V and 35W. It operates with a PK32d-2 base and includes an integral ignitor, making it a self-contained unit designed for projector-type housings.
The D2S shares the same 85V, 35W operating characteristics as the D1S but uses a P32d-2 base and requires a separate, external ignitor rather than a built-in one. It is not interchangeable with the D1S despite their similar electrical ratings.
For the GL450 high beam headlight, the 2007-2012 model years list only the H7. The 2013-2016 model years list both the D1S and H7, each tied to a specific headlamp system type.
The low beam headlight on the 2007 GL450 uses either the H7 for halogen capsule headlamps or the D2S for HID headlamps, making the 2007 model year the sole application of the D2S in these specifications.
From 2008 onward, the HID low beam option shifted from the D2S to the D1S. Because the D1S integrates its ignitor and the D2S does not, these two bulb types require different housing configurations and are not interchangeable.
The headlamp system type, whether halogen capsule or HID, determines the correct bulb for a given vehicle. Installing an H7 position in a housing designed for an HID projector, or vice versa, would represent a fitment mismatch.
Both the D1S and D2S conform to ECE standards and are rated for projector-type housings, but their differing base types and ignitor configurations mean each is specific to its own housing design.