The Mercedes-Benz ML550 high beam and low beam headlight bulbs utilize D1S and H7 bulb sizes depending on configuration. The replacement chart covers 2008 to 2014 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 operates at 12V and 55W with a single filament and 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 a high-intensity discharge xenon type rated at 85V and 35W. It uses a PK32d-2 base and incorporates an integral ignitor, making it designed specifically for projector-type housings. It is manufactured to ECE standards for European and worldwide markets.
Because the D1S includes a built-in ignitor and is engineered for projector-type housings, it is not interchangeable with halogen bulb types such as the H7, even where wattage or base configurations might otherwise suggest compatibility.
For the Mercedes-Benz ML550, the high beam headlight on 2008-2011 models uses only the H7 bulb, with no HID option listed for that position during those years.
From 2012-2014, the ML550 high beam headlight accepts either a D1S or an H7 bulb, with fitment determined strictly by whether the vehicle was equipped with HID or halogen capsule headlamps at the time of manufacture.
The low beam headlight on the ML550 offered both D1S and H7 fitments across the full 2008-2014 model year range, with selection dependent on the installed headlamp system type.
The H7 and D1S bulbs serve the same headlight positions on certain model years but are not substitutes for one another, as each requires a distinct housing type and electrical system to function correctly.
Both bulb types found in the ML550 specifications conform to ECE standards, reflecting a lighting system architecture aligned with European regulatory requirements rather than SAE standards used in North American-specific designs.