Oldsmobile Cutlass Headlight Bulb Size

Additional Notes

• The H5001 and H5006 sealed beam units are the most frequently specified bulb types across the Oldsmobile Cutlass headlight data, covering high beam and low beam positions respectively for model years 1961-1972. Both are ANSI-standard 12V sealed beam units, meaning the entire lens-reflector-filament assembly is replaced as one piece rather than swapping an individual bulb.
• The H5001 is a 4-inch square sealed beam unit used in the high beam position, while the H5006 is a 5.75-inch round sealed beam unit used in the low beam position. Despite serving the same generation of the Cutlass, these two units are not interchangeable due to their differing shapes and sizes.
• For 1973-1974, the Cutlass shifted to the H6024, a 7-inch round sealed beam unit for both high and low beam positions. This round format differs physically from the square H5001 and round H5006 units used in prior years, making cross-year substitution between these formats incompatible.
• The H6054, a 5x7-inch rectangular sealed beam unit, was specified for both the high beam and low beam positions in 1978-1979. Its rectangular form factor is distinct from the round H6024 and the 4x6-inch H4651 and H4652 units used in adjacent model years, so fitment is not shared across those years.
• In 1980, the low beam position used the H4656, a 4x6-inch rectangular sealed beam unit, while the high beam used the H4651. In 1981, the low beam changed to the H4652, which is a variant of the H4651. Although H4651 and H4652 share the same 4x6-inch rectangular form, they are distinct part numbers and are not confirmed as direct substitutes for one another.
• Starting with the 1997-1999 Cutlass, the headlight system moved away from sealed beam units entirely. The 9005 replaced sealed beams in the high beam position and the 9006 in the low beam position. Both are single-filament halogen bulbs with separate replaceable capsules, unlike every earlier sealed beam type listed in the specifications.
• The 9005 operates at 12V and 65W with a P20d base, while the 9006 operates at 12V and 55W with a P22d base. Although both are single-filament halogen bulbs of similar physical scale, their base types differ, making them non-interchangeable between the high and low beam sockets.
• All bulb types listed across the full span of Cutlass headlight specifications conform to ANSI standards applicable in the United States and Canada, meaning each sealed beam unit and each halogen capsule follows a standardized size and electrical specification within that regulatory framework.