The Volkswagen Scirocco uses a P21W bulb for the brake light assembly according to the provided technical specifications for the vehicle lighting system. The available information covers a span of production starting from 1975 through 1988.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Volkswagen Scirocco uses the P21W bulb for brake lighting across the 1975-1988 model years, making it the dominant bulb type in these specifications.
The P21W is an ECE-standard single-filament bulb rated at 12V and 21W, fitted with a BA15s bayonet base, a base type widely used in European automotive lighting applications.
The BA15s designation indicates a single-contact bayonet cap with a 15mm base, which is not interchangeable with the BA15d double-contact variant despite their similar physical appearance.
The Volkswagen Scirocco (1985-1988) uses the 12961 bulb for the Center High Mount Stop Light, a separate specification from the main brake light.
The 12961 is a Philips part number referencing a T10 miniature wedge bulb with a W2.1x9.5d base, rated at 12V and 5W, a significantly lower wattage than the P21W used in the primary brake lights.
The W2.1x9.5d wedge base of the 12961 bulb is physically incompatible with the BA15s bayonet base of the P21W, meaning the two bulb types are not interchangeable between positions.
The 21W output of the P21W reflects its role as a primary stop signal bulb, where higher luminous intensity is required for visibility in direct traffic sightlines.
The 5W rating of the T10 wedge bulb used in the Center High Mount Stop Light is consistent with its supplementary signalling function, where the mounting position at eye level compensates for the lower wattage.