Mercedes-Benz 300SEL Headlight Bulb Size

The Mercedes-Benz 300SEL uses high beam headlight bulbs in 9004 and H5001 sizes, while low beam headlight bulbs measure 9004 and H5006 in size. The replacement chart covers 1969 through 1991 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.

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
1988-1991	9004	HB1	Check Price
1969-1973	H5001	H5001	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
1988-1991	9004	HB1	Check Price
1969-1973	H5006	H5006	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). 4-inch square sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H5001	Check Price
ANSI standard (US & Canada). 5.75-inch round sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H5006	Check Price

Other Locations

Additional Notes

The 9004 is a dual-filament halogen bulb, meaning a single unit handles both high and low beam functions through two separate filaments. This is why the Mercedes-Benz 300SEL (1988-1991) uses the same 9004 size for both the high beam and low beam positions.
The 9004 operates at 12 volts and draws 65 watts on the high beam filament and 45 watts on the low beam filament. It uses a P29t base, which is a specific keyed connector that prevents incorrect installation orientation.
The H5001 and H5006 are sealed beam units rather than replaceable bulbs. The entire housing, reflector, and lens are fused into one assembly, so the whole unit is replaced when the light fails.
The H5001 is a 4-inch square sealed beam unit, while the H5006 is a 5.75-inch round sealed beam unit. These two types serve different beam functions on the 300SEL (1969-1973), with the H5001 designated for high beam and the H5006 for low beam.
All three bulb types in these specifications conform to ANSI standards applicable in the United States and Canada. This means they follow standardized physical and electrical specifications shared across many vehicle makes.
Because the H5001 and H5006 are separate units with different shapes and sizes, they are not interchangeable with each other, nor are they interchangeable with the 9004 used in later 300SEL model years.
All bulb types listed across both the 1969-1973 and 1988-1991 300SEL model years operate on a 12-volt electrical system, which is standard for passenger vehicles of these eras.
The 9004 bulb, used across the 1988-1991 300SEL, is a single replaceable halogen capsule rather than a sealed beam assembly, which distinguishes it fundamentally from the H5001 and H5006 units used in earlier model years.