The Simca 1118 front turn signal uses a 1157 bulb size while the rear turn signal requires a 1156 bulb size. The replacement chart covers 1969 to 1971 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Simca 1118 uses the 1157 bulb for the front turn signal across the 1969-1971 model years.
The 1157 is a dual-filament bulb rated at 12V with a 21W/5W output, meaning it operates one filament for steady running light duty and a second, brighter filament for signaling.
The 1157 uses a BAY15d bayonet base, which features two offset pins to prevent incorrect installation of the bulb into the socket.
The rear turn signal on the Simca 1118 uses the 1156 bulb across the same 1969-1971 model years.
The 1156 is a single-filament bulb rated at 12V and 21W, dedicated solely to its signaling function without a secondary running light filament.
The 1156 uses a BA15s bayonet base, which has a single pin, making it physically incompatible with the BAY15d socket used by the 1157 at the front position.
Both the 1157 and 1156 are ANSI standards recognized in the US and Canada, indicating standardized electrical and physical tolerances for those markets.
Although the 1157 and 1156 share the same 15mm base width and a similar bayonet-style mounting, the differing pin configurations mean the two bulb types are not interchangeable between the front and rear sockets of the Simca 1118.