Oldsmobile Calais Headlight Bulb Size

The Oldsmobile Calais uses 9004 and H4651 bulb sizes for high beam headlights, while low beam headlights require 9004, H4652, or H4656 bulb sizes. The replacement chart covers vehicle production years spanning 1985 to 1987 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
1987	9004	HB1	Check Price
1985-1986	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
1987	9004	HB1	Check Price
1986	H4652	H4652	Check Price
1985	H4656	H4656	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, variant of H4651. Not a replaceable bulb — the entire unit is replaced. 12V.	H4652	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

Other Locations

Additional Notes

The 1987 Oldsmobile Calais uses the 9004 bulb for both high beam and low beam headlights, meaning a single bulb type serves the entire headlight system for that model year.
The 9004 is a dual-filament halogen bulb with a P29t base, rated at 12V with separate wattage draws of 65W on high beam and 45W on low beam. The dual-filament design allows one physical bulb to produce two distinct light outputs within a single housing.
The 1985 and 1986 model years use sealed beam units rather than replaceable halogen bulbs. Sealed beam technology integrates the filament, reflector, and lens into one fixed unit, so the entire assembly is replaced rather than an individual bulb.
The H4651, H4652, and H4656 sealed beam units all conform to the 4x6-inch rectangular ANSI standard format and operate at 12V. This standardized physical format was a regulated specification common in North American vehicle lighting of that period.
For the 1986 Calais, the high beam uses the H4651 while the low beam uses the H4652. Although both are 4x6-inch rectangular sealed beam units, they are distinct part numbers and are not interchangeable between positions.
The 1985 Calais uses the H4651 for high beam and the H4656 for low beam. The H4656 differs from the H4652 used in the 1986 low beam position, making cross-year substitution between these two low beam units technically incorrect despite their shared sealed beam format.
All bulb and sealed beam specifications listed for the Calais conform to ANSI standards applicable in both the United States and Canada, indicating regulatory compliance across both markets.
The transition from sealed beam units in 1985-1986 to the 9004 halogen bulb in 1987 represents a shift in headlight technology, with the 9004 format allowing bulb-only replacement rather than full assembly replacement.