BMW 3.0 front and rear turn signal bulbs use a 1156 bulb size for this model. The replacement chart covers 1971 to 1974 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 BMW 3.0 (1971-1974) uses the 1156 bulb for both front and rear turn signals across all listed model years.
The 1156 is an ANSI-standardized bulb type, meaning its physical and electrical specifications conform to a defined North American standard recognized in the US and Canada.
The 1156 operates on a 12-volt electrical system and draws 21 watts, which places it in the category of standard incandescent automotive signaling bulbs.
The 1156 is a single-filament bulb, meaning it serves one lighting function only, as opposed to dual-filament types that can handle two functions such as braking and signaling simultaneously.
The BA15s designation refers to a bayonet-style base with a 15mm collar and a single locating pin, which determines physical socket compatibility and is not interchangeable with double-pin bayonet variants such as the BA15d.