The Mercedes-Benz E500 parking light requires bulb size 12961, 2357NA, or P21/5W depending on the specific application. Data for the bulb size chart covers the range from 1994 to 2006.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mercedes-Benz E500 front parking light position uses the 12961 across the 2003-2006 model years, making it the dominant bulb type in these specifications.
The 12961 is a Philips part number designating a miniature wedge-style T10 bulb with a W2.1x9.5d base, rated at 12V and 5W. The T10 form factor is a single-filament lamp commonly used in low-intensity indicator and parking applications.
The 2005 model year carries a second entry listing the 2357NA in place of the 12961 for the front parking light, indicating that two different bulb fitments are associated with that year.
The 2357NA is an ANSI-standard dual-filament bulb with a BAY15d bayonet base, rated at 12V with filaments drawing 26.9W and 8W respectively. Its natural amber glass produces a yellow-orange output without the use of a colored lens or coating.
The BAY15d base found on the 2357NA uses offset pins to ensure correct filament orientation, which is a physical safeguard against incorrect installation of a dual-filament bulb.
The P21/5W is listed for the 1994 E500 front parking light. It follows the ECE standard used in Europe and worldwide markets, and also uses a BAY15d bayonet base with dual filaments rated at 21W and 5W.
Although both the 2357NA and P21/5W share the BAY15d base type, they are not interchangeable. Their wattage ratings differ significantly, and they conform to separate regulatory standards, ANSI and ECE respectively.
The T10 wedge base of the 12961 is physically incompatible with the BAY15d bayonet base of the 2357NA and P21/5W, meaning bulbs from the 2003-2006 entries cannot be substituted into the 1994 fitment, and vice versa.
The single-filament design of the 12961 contrasts with the dual-filament construction of both the 2357NA and P21/5W, reflecting a functional difference in how the parking light circuit is configured across the model years covered.