The Mercedes-Benz 300SEL brake light utilizes P21W and 1141 bulb sizes for the lighting components. Data for the specific bulb requirements covers the period from 1969 through 1991.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The P21W is the dominant bulb type across the Mercedes-Benz 300SEL brake light specifications, appearing in both the standard brake light and center high mount stop light positions across multiple model years.
The P21W follows the ECE (Economic Commission for Europe) standard, which governs automotive lighting regulations across Europe and many other markets worldwide. It operates at 12V with a 21W output and uses a BA15s single-contact bayonet base.
The 1141 is an ANSI-standard bulb used in North American automotive applications. It shares the same 12V, 21W electrical rating as the P21W and also uses a BA15s bayonet base.
Despite originating from different regional standards, the P21W and 1141 share identical base types (BA15s), voltage (12V), and wattage (21W), which reflects their functional equivalence in single-filament signalling applications.
The Mercedes-Benz 300SEL uses the 1141 bulb for the brake light position in the 1970-1971 model years, while all other listed years specify the P21W for the same position.
The center high mount stop light position on the 300SEL specifies the P21W for the 1988-1991 model years.
The single-filament design of both the P21W and 1141 means each bulb serves one dedicated lighting function, as opposed to dual-filament bulbs that handle two functions such as running light and brake light within a single unit.
The BA15s bayonet base designation indicates a 15mm base with a single contact pin, a base type widely used in automotive stop and tail light applications across both European and North American vehicles.