Mercedes-Benz G63 AMG front side marker uses a 3893 bulb size while the rear side marker requires a 12821 bulb size. The replacement chart covers 2013 to 2018 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 Mercedes-Benz G63 AMG uses two distinct bulb types across its side marker positions for the 2013-2018 model years: the 3893 for front side markers and the 12821 for rear side markers.
The 3893 is an ANSI-standardized bulb recognized in both the United States and Canada, operating at 12V with a dual-filament design and a BAY15d bayonet base.
A BAY15d bayonet base features two pins offset at different heights, which physically prevents incorrect single-filament bulbs from seating in the socket, making accidental substitution with incompatible types unlikely.
The dual-filament construction of the 3893 means the bulb contains two separate circuits within a single envelope, each serving a distinct lighting function.
The 3893 is classified as a specialty application bulb, indicating its use is limited to specific vehicle positions rather than general-purpose automotive lighting.
The 12821 is a Philips part number designation for a miniature wedge-style bulb of the T10 form factor, rated at 12V and 5W, with a W2.1x9.5d wedge base.
The W2.1x9.5d base of the 12821 is a wedge-type connection with no pins, relying on contact pressure from the socket to maintain the electrical circuit.
The T10 form factor of the 12821 refers to a tubular bulb roughly 10 millimeters wide, a common size in low-wattage automotive marker and interior lighting applications.
The front and rear side marker positions on the G63 AMG use bases of fundamentally different designs, the BAY15d bayonet and the W2.1x9.5d wedge, making the two bulb types non-interchangeable with each other.
The 3893 and 12821 share the same 12V operating voltage, though their wattage, base type, and filament count differ, meaning voltage compatibility alone does not indicate fitment compatibility between the two positions.