Mercedes-Benz 280E front side marker bulbs use a P21/5W size, while rear side marker bulbs use a 3893 size. The replacement chart covers 1977 to 1981 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 280E uses two distinct bulb types across its front and rear side marker positions for the 1977-1981 model years, with each position requiring a specific bulb throughout the entire production span covered by these specifications.
The P21/5W is a dual-filament bulb operating at 12V with a 21W main filament and a 5W secondary filament, housed in a BAY15d bayonet base. It conforms to ECE standards, making it the predominant bulb type in European and worldwide automotive applications.
The BAY15d bayonet base features two offset pins at different heights, a design that physically prevents incorrect single-filament bulbs from being seated in a dual-filament socket. Both the P21/5W and the 3893 share this base type.
The front side marker position on the 280E calls for the P21/5W across all five model years in these specifications, indicating a consistent European-standard fitment for that position.
The 3893 is an ANSI-standard dual-filament bulb rated at 12V with a BAY15d bayonet base, classified as a specialty application bulb under North American standards. It serves the rear side marker position on the 280E for all model years listed.
Although the P21/5W and the 3893 share the same BAY15d base type, they are governed by different standards bodies, ECE and ANSI respectively, and are designated for separate positions on the vehicle. Substituting one for the other is not supported by these specifications.
The dual-filament construction of both bulb types is relevant to side marker applications, where a secondary low-intensity filament can serve a parking or position light function alongside the primary signalling filament.