The Mercedes-Benz GL350 high beam and low beam headlight bulbs utilize D1S and H7 bulb sizes depending on configuration. The replacement chart covers 2010 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 H7 bulb is a single-filament halogen type operating at 12V and 55W, with a PX26d base. It carries ECE approval for European and worldwide use and is also approved for use in the United States and Japan.
The D1S bulb is an HID (xenon) gas-discharge type rated at 85V and 35W, with a PK32d-2 base and an integral ignitor built into the bulb body. It is designed specifically for projector-type headlamp housings and follows the ECE standard.
Because the D1S includes an integral ignitor, it is not interchangeable with HID bulb types that require a separate external ignitor, even when wattage or voltage ratings are similar.
The Mercedes-Benz GL350 uses both the D1S and H7 across its headlight positions, with the correct bulb determined by which headlamp system is installed on the vehicle, either HID or halogen capsule.
For the 2013-2016 model years, both the high beam and low beam positions list either a D1S or an H7, depending on the headlamp type fitted. This dual-listing reflects a factory option between HID and halogen capsule headlamp systems.
For the 2010-2012 model years, the high beam position lists only the H7, while the low beam position lists both the D1S and H7 as options. This indicates that HID fitment on those years was limited to the low beam function.
The H7 and D1S operate on fundamentally different electrical systems. The H7 runs on a standard 12V vehicle circuit, while the D1S requires the 85V output of a dedicated HID ballast. The two bulb types are not electrically or physically compatible with each other's housings.
The PX26d base of the H7 and the PK32d-2 base of the D1S are distinct and non-interchangeable mounting formats, meaning physical installation into the wrong housing is not possible without modification.