The Mercedes-Benz S55 AMG front fog light uses H7 and H1 bulb sizes, while the rear fog light requires a P21/4W bulb size. The replacement chart covers 2001 to 2006 model 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 S55 AMG uses two distinct front fog light bulb types across its production run, with the H1 fitted to 2001-2002 models and the H7 fitted to 2003-2006 models.
The H7 is a single-filament halogen bulb operating at 12V and 55W, mounted on a PX26d base. It conforms to ECE standards and holds approval in the US and Japan.
The H1 is also a single-filament halogen bulb rated at 12V and 55W, but it uses a P14.5s base rather than the PX26d base of the H7. The two bulbs are not interchangeable despite sharing the same wattage and voltage rating.
The base type difference between the H1 and H7 is a critical fitment factor for the S55 AMG. Installing an H7 in a housing designed for an H1, or vice versa, is not physically compatible due to the differing base configurations.
The rear fog light specification for the S55 AMG remains consistent across all model years from 2001-2006, with the P21/4W bulb used throughout.
The P21/4W is a dual-filament signalling bulb rated at 12V with a 21W main filament and a 4W secondary filament. It uses a BAZ15d bayonet base, which is an offset-pin design that prevents incorrect installation of single-filament alternatives.
The BAZ15d base of the P21/4W is distinct from standard single-filament bayonet bases, meaning single-filament P21W bulbs are not a direct mechanical substitute in the rear fog light housing.
All three bulb types specified for the S55 AMG conform to ECE regulations, which govern bulb performance and safety standards across European and many international markets.