Mercedes-Benz CLK550 high beam headlight bulbs use H7 size, while low beam headlight bulbs use H7 or D2S sizes depending on configuration. The replacement chart covers 2007 to 2009 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 the most frequently specified type across the Mercedes-Benz CLK550 headlight data, appearing in both high beam and halogen low beam positions for the 2007-2009 model years.
The H7 is a single-filament halogen bulb rated at 12V and 55W, built to ECE standards with a PX26d base, and carries approval for use in Europe, worldwide markets, the United States, and Japan.
The D2S is a high-intensity discharge bulb rated at 85V and 35W, fitted with a P32d-2 base, and is designed exclusively for projector-type headlamp housings. It requires an external ignitor to initiate and sustain the arc discharge.
For the 2007-2009 CLK550, the low beam position accommodates two distinct bulb types depending on the headlamp system installed at the factory: H7 for halogen capsule headlamps and D2S for HID headlamps. These two types are not interchangeable.
The high beam position on the 2007-2009 CLK550 is specified exclusively for the H7 bulb, with no HID variant listed for that function.
The H7 and D2S bulbs use different bases, PX26d and P32d-2 respectively, meaning a socket designed for one will not physically accept the other, reinforcing that headlamp system type must be confirmed before a replacement bulb is selected.
The D2S operates at 85V, a significantly higher voltage than the H7's 12V supply, which reflects the fundamental electrical difference between HID discharge systems and conventional halogen circuits.