The Mercedes-Benz S430 front fog light requires H7 or H1 bulb size, while the rear fog light uses P21/4W bulb size. The replacement chart covers 2000 to 2006 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 Mercedes-Benz S430 front fog light specification changed from H1 to H7 between the 2002 and 2003 model years, meaning the two generations of this vehicle within the 2000-2006 production span are not interchangeable in this position.
The 2003-2006 S430 front fog lights use the H7 bulb, an ECE-standard single-filament halogen type rated at 12V and 55W, fitted with a PX26d base.
The 2000-2002 S430 front fog lights use the H1 bulb, also an ECE-standard single-filament halogen type rated at 12V and 55W, but fitted with a P14.5s base instead.
Although both H7 and H1 share the same 12V and 55W electrical ratings, their bases are physically different and incompatible with each other, making substitution between the two impossible without a housing change.
Both H7 and H1 carry ECE approval and are also approved for use in the United States and Japan, reflecting broad international regulatory acceptance.
The rear fog light position uses the P21/4W bulb across the entire 2000-2006 model range, indicating no change in specification for that position throughout this period.
The P21/4W is a dual-filament signalling bulb rated at 12V with a 21W main filament and a 4W secondary filament, fitted with a BAZ15d bayonet base.
The BAZ15d base of the P21/4W is an offset bayonet type, a design that prevents incorrect installation by ensuring the bulb can only be seated in one orientation.
The P21/4W carries ECE standard approval for use in Europe and worldwide, consistent with the international regulatory standing of the other bulb types specified for this vehicle.