The Mercedes-Benz CLK320 high beam headlight uses an H7 bulb size, while low beam headlights accommodate H7, D2S, or D2R bulb sizes. The replacement chart covers 1998 through 2005 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 widely used type across the Mercedes-Benz CLK320 headlight specifications, appearing in every model year from 1998-2005 for the high beam position and as one of two low beam options throughout the same period. It is a single-filament halogen bulb rated at 12V and 55W, fitted with a PX26d base, and carries ECE certification with approval also extended to the US and Japan.
The high beam headlight position uses the H7 bulb exclusively across all CLK320 model years covered in the specifications, from 1998-2005, with no alternative bulb type listed for that function.
The low beam position on the CLK320 accommodates two distinct headlamp systems depending on the installed equipment. Halogen-equipped vehicles use the H7 bulb, while vehicles fitted with HID headlamps use a discharge bulb, either D2R or D2S, depending on the model year.
The D2R bulb applies to HID low beam configurations on the CLK320 for model years 1998-2002. It is an HID xenon discharge bulb rated at 85V and 35W, fitted with a P32d-3 base, and is specifically designed for reflector-type headlamp housings. It requires an external ignitor to operate.
The D2S bulb replaces the D2R in HID low beam configurations for model years 2003-2005. It shares the same 85V and 35W electrical rating but uses a P32d-2 base and is intended for projector-type headlamp housings rather than reflector-type units.
The D2R and D2S bulbs are not interchangeable despite sharing identical wattage and voltage ratings. The difference in base type, P32d-3 for D2R and P32d-2 for D2S, reflects a physical and optical distinction tied to the housing design, making cross-substitution incompatible without a matching housing change.
Both D2R and D2S bulbs operate on the HID principle, in which an electrical arc passes between two electrodes within a xenon gas-filled capsule. This differs fundamentally from the resistive filament heating used in the H7 halogen bulb, and both HID types require a separate external ignitor as part of the circuit.
The H7 and the D-series HID bulbs all carry ECE certification, meaning they conform to the Economic Commission for Europe lighting standard that governs beam pattern, intensity, and color output for road use across Europe and numerous other markets worldwide.