The Mercedes-Benz 300SDL uses 9004 bulb size for both high beam and low beam headlight applications. The replacement chart covers 1986 to 1987 vehicle 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 9004 is a dual-filament halogen bulb, meaning a single bulb contains two separate filaments that serve two distinct functions. The higher-output filament operates at 65 watts for high beam use, while the lower-output filament operates at 45 watts for low beam use.
The 9004 bulb uses a P29t base, which is a three-contact plastic base designed to allow the vehicle's electrical system to activate either filament independently depending on the selected beam mode.
The 9004 operates on a 12-volt electrical system, which is standard for passenger vehicles in this class.
The Mercedes-Benz 300SDL uses the 9004 bulb for both the high beam and low beam headlight positions across the 1986-1987 model years, meaning a single bulb type serves both functions in each headlight housing.
The 9004 carries ANSI standardization and is approved for use in the United States and Canada, indicating it meets the photometric and safety requirements established by North American regulatory bodies.
Because the 9004 is a dual-filament bulb handling both beam functions, it is not interchangeable with single-filament bulbs such as the 9005 or 9006, which are dedicated to high beam or low beam use respectively.