The Mercedes-Benz SLK55 AMG front fog light requires 9006 and H7 bulb sizes, while the rear fog light uses a P21W bulb size. The replacement chart covers 2005 to 2010 model production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mercedes-Benz SLK55 AMG front fog light specifications list two distinct bulb types across model years: the 9006 and the H7. Both operate at 12V and 55W, making them electrically equivalent, but they are not interchangeable due to differing base designs.
The 9006 uses a P22d base and is governed by ANSI standards, which are the prevailing standards in the United States and Canada. It is a single-filament halogen bulb rated at 12V and 55W.
The H7 uses a PX26d base and follows ECE standards, which apply across Europe and much of the world. It is also approved for use in the United States and Japan. Like the 9006, it is a single-filament halogen bulb rated at 12V and 55W.
Because the P22d and PX26d bases are physically different, a 9006 bulb cannot be substituted for an H7, and vice versa, despite their identical voltage and wattage ratings.
The front fog light specification for the SLK55 AMG is not uniform across all model years. The 2005, 2008, and 2009 model years call for the H7, while the 2006, 2007, and 2010 model years call for the 9006.
The alternating front fog light bulb types across model years indicates that direct year-to-year parts substitution for the front fog light position is not reliable without confirming the specific model year requirement.
The rear fog light specification for the SLK55 AMG is consistent across all listed model years, with the P21W bulb specified for 2005-2010.
The P21W is a single-filament signalling bulb rated at 12V and 21W. It uses a BA15s bayonet base and is governed by ECE standards.
The BA15s designation on the P21W denotes a single-contact bayonet cap with a 15mm base width. This base type is distinct from the screw and wedge bases found on other common automotive signalling bulbs, and fitment requires a compatible bayonet socket.
The P21W's 21W output is notably lower than the 55W rating of the front fog light bulbs, reflecting its role as a signalling lamp rather than an illumination source.