Porsche 928 Headlight Bulb Size

Porsche 928 high and low beam headlight bulbs utilize a 9004 or H6024 bulb size for both functions. The replacement chart covers vehicle production spanning 1978 to 1995 with corresponding bulb 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
1993-1995	9004	HB1	Check Price
1987-1991	9004	HB1	Check Price
1978-1986	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
1993-1995	9004	HB1	Check Price
1987-1991	9004	HB1	Check Price
1978-1986	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 Porsche 928 uses two distinct headlight technologies across its production span, with the H6024 sealed beam unit fitted to 1978-1986 models and the 9004 halogen bulb fitted to 1987-1995 models (excluding 1992).
The 9004 is a dual-filament halogen bulb operating at 12V with a high beam draw of 65W and a low beam draw of 45W, using a P29t base. A single bulb serves both the high and low beam functions through its two filaments.
The H6024 is a 7-inch round sealed beam unit conforming to ANSI standards for the US and Canadian markets. Because the lens, reflector, and filament are fused into one assembly, the entire unit is replaced rather than an internal bulb.
On the Porsche 928, the 9004 bulb specification is identical for both the high beam and low beam positions across all applicable years, which reflects the dual-filament nature of the 9004 rather than the use of separate single-filament bulbs per function.
The H6024 and 9004 are not interchangeable. They differ in physical form, base type, and construction, meaning fitment is strictly determined by the model year of the vehicle.
Both the H6024 and 9004 are ANSI-standardized types approved for the US and Canadian markets, indicating compliance with North American photometric and safety regulations.
The 9004 bulb type carries a P29t base, which is a specific bayonet-style connector. Substitutes using different base configurations are not compatible with the 928's headlight housing for those years.