The Mercedes-Benz 300SL front side marker uses a 12961 bulb size while the rear side marker requires a 5008 bulb size. The replacement chart covers 1990 to 1993 production years with corresponding 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 300SL uses two distinct bulb types across its front and rear side marker positions for the 1990-1993 model years.
The 12961 is a Philips part number designation for a T10 miniature wedge bulb. It uses a W2.1x9.5d base and operates at 12V with a 5W output.
The T10 wedge base of the 12961 is a push-fit design, meaning it seats directly into a socket without rotation, which is a common trait of low-wattage miniature lighting applications.
The 12961 bulb is specified for the front side marker position across all four model years covered in the specifications.
The 5008 follows the ANSI standard recognized in both the United States and Canada. It uses a BA15s single-contact bayonet base and operates at 12V.
The BA15s base of the 5008 is a single-contact bayonet mount, which means it locks into its socket with a twist and cannot be substituted with a BA15d double-contact base without a fitment mismatch.
The 5008 is described as a lower wattage variant of the 1156 bulb. While both share the BA15s bayonet base, the wattage difference means the two are not interchangeable without affecting electrical load and light output.
The 5008 bulb is specified for the rear side marker position across all four model years covered in the specifications.
Because the front and rear positions use physically incompatible base types, a 12961 wedge bulb cannot be installed in a rear socket designed for the BA15s bayonet mount of the 5008, and vice versa.
The split between a Philips-designated part number at the front and an ANSI-standard part number at the rear reflects a common practice in European-market vehicles sold in North America, where front and rear lighting components may source from different specification systems.