The Mercedes-Benz 400E uses 9004 bulb size for both high beam and low beam headlight applications. The replacement chart covers 1992 to 1993 model 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 9004 is a dual-filament halogen bulb operating at 12 volts, with a high-beam filament rated at 65 watts and a low-beam filament rated at 45 watts. Its P29t base is a three-contact connector that allows a single bulb to serve both beam functions within one housing.
The Mercedes-Benz 400E uses the 9004 bulb across both the high beam and low beam headlight positions for the 1992-1993 model years, meaning a single bulb type handles both lighting functions rather than separate bulbs for each.
The 9004 is an ANSI-standardized bulb type recognized in the United States and Canada, which means its physical and electrical specifications conform to a defined North American standard rather than an international ECE standard.
Because the 9004 serves as both the high beam and low beam bulb on the 400E, the two filaments within the bulb are switched independently by the vehicle's electrical system depending on the selected beam mode.
The P29t base of the 9004 is not interchangeable with single-filament halogen bases such as the H1 or H7, nor with the dual-filament 9007 base, despite the 9007 sharing a similar wattage profile. Physical keying differences between these base types prevent cross-installation.