The Rolls-Royce Silver Shadow front turn signal requires a 1156, 1159, or 1157 bulb size, while the rear turn signal uses a P21W or 1157 bulb size. The replacement chart covers vehicle production years spanning 1966 to 1976.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 1156 bulb is an ANSI-standard single-filament type rated at 12V and 21W, fitted with a BA15s bayonet base. It serves as the front turn signal bulb in the Rolls-Royce Silver Shadow for the 1970-1972 and 1975-1976 model years.
The 1157 bulb is an ANSI-standard dual-filament type rated at 12V with a 21W/5W output split across its two filaments, fitted with a BAY15d bayonet base. It covers the front turn signal position for the 1966-1969 model years.
The 1159 bulb is an ANSI-standard dual-filament type rated at 12V, also using a BAY15d bayonet base. It occupies the front turn signal position for the 1973-1974 model years.
The BAY15d base used by both the 1157 and 1159 bulbs features offset pins to prevent incorrect single-filament substitution. Despite sharing this base type, the two bulbs are not confirmed interchangeable, as their wattage ratings differ.
The 1156 and P21W bulbs share the same BA15s bayonet base and identical electrical ratings of 12V and 21W. However, the 1156 follows the ANSI standard used in the United States and Canada, while the P21W follows the ECE standard used in Europe and worldwide.
The rear turn signal position of the Silver Shadow uses the P21W bulb for the 1973-1976 model years. This ECE-standard fitment reflects the vehicle's European engineering origins during that period.
The rear turn signal position uses the 1157 dual-filament bulb for the 1966-1972 model years. This differs from the single-filament P21W used in later years, meaning the rear lamp assemblies across the production run are not electrically equivalent.
The front and rear turn signal positions do not share the same bulb type across all model years. For example, in 1973-1974, the front position takes the dual-filament 1159 while the rear takes the single-filament P21W, making cross-position substitution inappropriate for those years.
The Silver Shadow's turn signal specifications draw from two separate standardization systems, ANSI and ECE, across its production run. The ANSI types (1156, 1157, 1159) appear in the front positions throughout, while the ECE type (P21W) appears exclusively in the rear position from 1973 onward.
The 1157 bulb is the most broadly represented type across the Silver Shadow's turn signal specifications, appearing in both the front position for 1966-1969 and the rear position for 1966-1972.