The Mercedes-Benz SL320 front side marker bulb uses a 2357NA size with P21/5W specifications, while the rear side marker bulb requires a 5008 or 232 size. The replacement chart covers 1994 to 1997 model 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 SL320 front side marker position uses two distinct bulb types across its 1994-1997 model years: the P21/5W for 1994-1995 and the 2357NA for 1996-1997.
The 2357NA and P21/5W bulbs both share the BAY15d bayonet base, which is a dual-contact base designed to accommodate dual-filament bulbs. Despite this shared base type, the two bulbs follow different international standards and are not interchangeable without consideration of wattage and regulatory compliance.
The 2357NA follows the ANSI standard applicable in the US and Canada, while the P21/5W follows the ECE standard used in Europe and worldwide markets. This distinction reflects a regional specification change in the SL320 front side marker between the 1995 and 1996 model years.
The wattage ratings of the 2357NA (26.9W/8W) and P21/5W (21W/5W) differ across both filaments, meaning substituting one for the other would alter the electrical load and light output at the front side marker position.
The 2357NA features natural amber glass, which produces its amber color through the glass coating rather than through a colored lens or housing. This is a relevant fitment characteristic when the vehicle's lens is clear rather than amber-tinted.
The rear side marker position of the SL320 uses the 5008 bulb for 1994 and 1996-1997, while the 1995 model year uses the 232 festoon bulb instead.
The 5008 is a single-filament bulb with a BA15s bayonet base, which is a single-contact base distinct from the dual-contact BAY15d base used at the front side marker position. These two base types are physically incompatible with each other.
The 5008 is described as a lower wattage variant of the 1156 bulb. Both share the BA15s base, but the reduced wattage of the 5008 means the 1156 is not a direct drop-in replacement, as it would draw more power than the socket was specified for.
The 232 festoon bulb used at the 1995 SL320 rear side marker position uses an SV8.5 base, a tubular form factor that is physically incompatible with the BA15s bayonet socket required by the 5008. The two bulb types cannot be substituted for one another.
The 232 festoon bulb is rated at 3W, making it a notably low-output lamp relative to the other bulb types specified for the SL320. Its single-filament, festoon form factor is common in applications where space constraints or low current draw are relevant factors.