Mercedes-Benz 300D Headlight Bulb Size

The Mercedes-Benz 300D uses 9004 and H6024 bulb sizes for both high beam and low beam headlight applications. The replacement chart covers vehicle production spanning 1975 to 1993 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.

High Beam Headlight

If US Type and EU Type show the same value, a direct cross-reference for this bulb is not available or the data is insufficient.

Years	US Type	EU Type	Shop
1990-1993	9004	HB1	Check Price
1987	9004	HB1	Check Price
1975-1985	H6024	H6024	Check Price

Low Beam Headlight

If US Type and EU Type show the same value, a direct cross-reference for this bulb is not available or the data is insufficient.

Years	US Type	EU Type	Shop
1990-1993	9004	HB1	Check Price
1987	9004	HB1	Check Price
1975-1985	H6024	H6024	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Dual-filament halogen bulb with P29t base. 12V, 65W/45W.	9004	Check Price
ANSI standard (US & Canada). 7-inch round sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H6024	Check Price

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Additional Notes

The Mercedes-Benz 300D uses two distinct headlight bulb types across its model years: the 9004 halogen bulb and the H6024 sealed beam unit. Both conform to ANSI standards applicable in the United States and Canada.
The 9004 is a dual-filament halogen bulb rated at 12V with a 65W high beam filament and a 45W low beam filament, mounted on a P29t base. A single bulb serves both the high beam and low beam functions through its two filaments.
The H6024 is a 7-inch round sealed beam unit rated at 12V. Unlike a conventional replaceable bulb, the H6024 integrates the filament, reflector, and lens into one assembly, meaning the entire unit is replaced when the light fails.
The 300D used the H6024 sealed beam unit for both high beam and low beam headlights across the 1975-1985 model years, with the exception of 1986.
The 9004 halogen bulb replaced the H6024 sealed beam unit on the 300D for the 1987 and 1990-1993 model years, serving both high beam and low beam positions.
Because the 9004 and H6024 are fundamentally different in construction, one is not a direct substitute for the other. The 9004 is a socketed halogen bulb, while the H6024 is a self-contained sealed beam assembly requiring a compatible housing.
The P29t base on the 9004 bulb is a specific connector type, and substituting a bulb with a different base configuration would result in an incompatible fit regardless of voltage or wattage ratings.
The dual-filament design of the 9004 means that a single bulb position in the headlight housing handles both beam modes, whereas sealed beam units of the H6024 type typically require separate housings or units for each beam function depending on the vehicle's headlight configuration.