The Mercedes-Benz 560SEL uses a P21/5W bulb size for front side marker applications and a 3893 bulb size for rear side marker positions. The replacement chart covers 1986 through 1991 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 560SEL uses two distinct bulb types across its side marker positions: the P21/5W for the front and the 3893 for the rear, covering all model years from 1986-1991.
The P21/5W is an ECE-standard bulb, meaning it conforms to European and international regulations rather than North American standards.
As a dual-filament bulb, the P21/5W carries two separate wattage ratings: 21W for its primary filament and 5W for its secondary filament, operating on a 12V system.
The P21/5W uses a BAY15d bayonet base, a two-pin offset base design where the two pins are positioned at different heights to prevent incorrect installation.
The 3893 is an ANSI-standard bulb, placing it within the North American standardization system rather than the ECE framework used by the front marker bulb.
Despite originating from different standardization systems, both the P21/5W and the 3893 share the BAY15d bayonet base and are both dual-filament bulbs operating on a 12V system.
The shared BAY15d base between the two bulb types does not indicate interchangeability, as the P21/5W carries explicit wattage ratings of 21W/5W while the 3893 is designated for specialty applications with no equivalent wattage pairing listed.