Audi 4000 Headlight Bulb Size

The Audi 4000 high beam headlight bulb size measures 9004 or H4651, while low beam headlight bulb sizes measure 9004, H4656, or H4652. The replacement chart covers 1980 to 1987 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
1985-1987	9004	HB1	Check Price
1980-1984	H4651	H4651	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
1985-1987	9004	HB1	Check Price
1984	H4656	H4656	Check Price
1982-1983	H4652	H4652	Check Price
1981	H4656	H4656	Check Price
1980	H4652	H4652	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). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4651	Check Price
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4656	Check Price
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit, variant of H4651. Not a replaceable bulb — the entire unit is replaced. 12V.	H4652	Check Price

Other Locations

Additional Notes

The 9004 is a dual-filament halogen bulb operating at 12V with a P29t base, rated at 65W on the high beam filament and 45W on the low beam filament. Its single housing serves both beam functions, which distinguishes it from single-filament designs that require separate units for each beam.
The Audi 4000 (1985-1987) uses the 9004 bulb for both high beam and low beam positions, meaning one bulb type covers both functions in a single housing for those model years.
The H4651, H4652, and H4656 are all 4x6-inch rectangular sealed beam units operating at 12V under the ANSI standard applicable in the US and Canada. In a sealed beam design, the reflector, lens, and filament are fused into one unit, so the entire assembly is replaced rather than just a bulb.
The Audi 4000 (1980-1984) uses sealed beam units across all high beam and low beam positions, with H4651 designated for high beam use throughout those years.
Low beam fitment on the Audi 4000 varies across the 1980-1984 range. The H4652, a variant of the H4651, is specified for low beam use in 1980, 1982, and 1983, while the H4656 appears in 1981 and 1984 for the same position.
The H4652 is described as a variant of the H4651, and both share the same 4x6-inch rectangular sealed beam format. Despite their physical similarity, they carry distinct ANSI designations and are not confirmed as interchangeable by the specifications.
All bulb types listed across the Audi 4000 specifications conform to ANSI standards recognized in the US and Canada, indicating standardized sizing and electrical ratings within that regulatory framework.
The transition from sealed beam units to the 9004 halogen bulb occurs between the 1984 and 1985 model years, reflecting a shift from a fixed-assembly format to a replaceable-bulb format with a discrete P29t base.