The Mercedes-Benz CLS550 headlight bulb specifications include D1S, H7, and D2S sizes for high and low beam applications. The replacement chart covers 2007 to 2014 model years with corresponding bulb size data.
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 rated at 12V and 55W, operating on a PX26d base. It carries ECE approval for use in Europe and worldwide, and is also approved for use in the United States and Japan.
The D1S and D2S bulbs are both HID (xenon) gas-discharge types rated at 85V and 35W, each designed for projector-type housings. Despite sharing the same wattage and voltage ratings, the two types are not interchangeable due to differences in base design and ignition configuration.
The D1S uses a PK32d-2 base and incorporates an integral ignitor within the bulb itself, whereas the D2S uses a P32d-2 base and requires a separate external ignitor. This distinction makes the two bulbs physically and electrically incompatible with each other's housings.
On the Mercedes-Benz CLS550, the high beam headlight used the H7 bulb for model years 2007-2011, then transitioned to the D1S for 2012-2014, the latter applying only to vehicles equipped with HID headlamps.
The low beam headlight for 2007-2011 model years lists both H7 and D2S as applicable sizes, with the D2S entry specifically noted for vehicles equipped with HID headlamps, indicating two distinct headlamp system configurations existed across those years.
For 2012-2014, the CLS550 low beam headlight uses the D1S exclusively under the HID headlamp designation, replacing the dual-option arrangement present in earlier model years.
The 2011 model year represents a transitional point in the high beam specification, as it is the last year listed with the H7 and the first year in which the D1S appears in the low beam position for HID-equipped vehicles.
All three bulb types listed in these specifications conform to ECE standards, which govern bulb construction and performance requirements across European and international markets.