The Mercedes-Benz CLK55 AMG front fog light utilizes H7, 9006, and H1 bulb sizes, while the rear fog light requires P21/4W and P21W bulb sizes. The replacement chart covers 2001 to 2006 production 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 Mercedes-Benz CLK55 AMG uses three distinct front fog light bulb types across its model years: H1, 9006, and H7, all rated at 12V and 55W.
The H1 and H7 bulbs follow ECE standards, meaning they are approved for use in Europe, worldwide markets, the United States, and Japan, while the 9006 follows the ANSI standard applicable to the US and Canada.
Although the H1, H7, and 9006 share identical voltage and wattage ratings of 12V and 55W, their bases differ: the H1 uses a P14.5s base, the H7 uses a PX26d base, and the 9006 uses a P22d base, making them physically non-interchangeable.
The front fog light on the CLK55 AMG (2001-2002) takes an H1 bulb, which is a single-filament halogen type with a P14.5s pin base.
For model years 2003-2005, the front fog light specification shifts to the 9006, a single-filament halogen bulb with a P22d base conforming to ANSI standards.
The 2006 model year front fog light uses an H7 bulb, a single-filament halogen type with a PX26d base under ECE standards.
The rear fog light on the CLK55 AMG (2001-2002) uses a P21W bulb, a single-filament signalling bulb with a BA15s bayonet base rated at 12V and 21W.
From 2003-2006, the rear fog light specification changes to the P21/4W, a dual-filament signalling bulb with a BAZ15d bayonet base rated at 12V with filaments at 21W and 4W.
The P21W and P21/4W are not interchangeable despite their similar naming, as they differ in filament count and base type: the BA15s base of the P21W has a single contact, while the BAZ15d base of the P21/4W features offset pins to accommodate its dual-filament design.
All rear fog light bulbs specified for the CLK55 AMG across all listed model years conform to ECE standards.