Mercedes-Benz 230S front and rear turn signal bulbs use P21W size. The replacement chart covers 1966 to 1969 production years with bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The P21W is the sole bulb type specified for the Mercedes-Benz 230S across all listed turn signal positions and model years.
P21W is an ECE-standard single-filament bulb rated at 12 volts and 21 watts, designed for signalling applications such as turn signals.
The BA15s bayonet base is a single-contact fitting, distinguished from the dual-contact BA15d base. This distinction is relevant when sourcing replacement bulbs, as the two base types are not interchangeable despite their similar appearance.
Both the front and rear turn signal positions on the 230S use the P21W for the 1966-1969 model years, meaning a single bulb type serves all four turn signal sockets on the vehicle.
The ECE designation indicates the P21W conforms to United Nations Economic Commission for Europe regulations, a standard adopted across European and many worldwide markets.
At 21 watts, the P21W produces a relatively high output for a single-filament bulb, which is a characteristic intentional for signalling visibility rather than illumination.