The Mercedes-Benz 560SEL brake light utilizes a P21W bulb size for illumination across all listed vehicle configurations. Data for the specified lighting component covers the period from 1986 through 1991.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mercedes-Benz 560SEL uses the P21W bulb type across all brake light positions for the 1986-1991 model years.
The P21W is an ECE-standardized single-filament bulb rated at 12 volts and 21 watts, designed primarily for signalling applications such as brake and stop lights.
P21W bulbs use a BA15s bayonet base, which is a single-contact bayonet fitting with a 15mm collar.
The BA15s base designation indicates a single-contact configuration, distinguishing it from the dual-contact BA15d variant, which is not specified for this vehicle.
The same P21W specification applies to both the standard brake lights and the Center High Mount Stop Light on the 560SEL across the full 1986-1991 production span.
The ECE designation on the P21W reflects compliance with United Nations Economic Commission for Europe regulations, a standard adopted across European and many international markets.
At 21 watts, the P21W produces a relatively high output for an incandescent signal bulb, which is consistent with its use in brake and stop light applications where visibility is a safety requirement.
Because the P21W and the dual-filament P21/5W share the same BA15 collar size but differ in contact configuration, the two types are not interchangeable despite their physical similarity.