Mercedes-Benz G65 AMG front side marker bulb uses 3893 size while rear side marker bulb uses 12821 size. Replacement chart covers 2016 to 2018 model years with bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mercedes-Benz G65 AMG uses two distinct bulb types across its side marker positions for the 2016-2018 model years: the 3893 for the front and the 12821 for the rear.
The 3893 is an ANSI-standardized bulb, meaning its specifications are governed by a recognized North American industry standard applicable in both the US and Canada.
As a dual-filament bulb, the 3893 contains two separate filaments within a single envelope, allowing it to serve more than one lighting function depending on how the circuit activates each filament.
The 3893 uses a BAY15d bayonet base, a two-pin offset bayonet mount where the two pins are positioned at different heights to ensure correct polarity orientation during installation.
The 12821 is a Philips part number designation for a miniature wedge-style bulb in the T10 form factor, which is among the most widely used small bulb formats in automotive applications.
The T10 wedge bulb uses a W2.1x9.5d base, a pinless design that is retained by the socket through friction on the wedge-shaped glass envelope rather than by a locking pin or bayonet mechanism.
The 12821 is rated at 12V and 5W, placing it in the low-wattage category typical of marker and courtesy lighting rather than primary illumination functions.
The 3893 and 12821 are not interchangeable, as they differ in base type, filament count, and physical form factor, making each one position-specific on the G65 AMG.