Chevrolet Cavalier Headlight Bulb Size

Additional Notes

• The 9007 bulb is a dual-filament halogen type with a PX29t base, rated at 12V with 65W on high beam and 55W on low beam. Its dual-filament design allows a single bulb to serve both high and low beam functions, which is reflected in the Chevrolet Cavalier's 2000-2005 specifications, where the same 9007 size is listed for both beam positions.
• The 9004 bulb shares the dual-filament halogen design but uses a P29t base and carries a lower wattage rating of 65W/45W at 12V. The P29t and PX29t bases are physically distinct and not interchangeable, meaning a 9004 and a 9007 cannot substitute for one another despite both being dual-filament types. The Cavalier used the 9004 across both beam positions for the 1991-1994 model years.
• For the 1988-1990 model years, the Cavalier's high beam and low beam positions required separate single-filament bulbs rather than one dual-filament unit. The high beam position used the 9005 with a P20d base at 65W, while the low beam position used the 9006 with a P22d base at 55W. The differing base types mean these two bulbs are not interchangeable with each other.
• The H6054 is a 5x7-inch rectangular sealed beam unit operating at 12V. In sealed beam construction, the reflector, lens, and filament form a single sealed assembly, so the entire unit is replaced rather than an internal bulb. The Cavalier's 1982-1983 model years used the H6054 for both high and low beam positions.
• The 4x6-inch sealed beam units, H4651, H4652, and H4656, were used across the 1984-1987 model years. H4652 is a variant of H4651, and H4656 is a separate 4x6-inch unit. Because these are sealed beam assemblies, replacement involves the full housing unit rather than a separate bulb component.
• The low beam position on the 1984 and 1986 Cavalier used the H4652, while the 1985 and 1987 low beam position used the H4656. The high beam position for all four of those years used the H4651. This means the high and low beam positions in that period required different sealed beam units and were not interchangeable with one another.
• All bulb and sealed beam types listed across the full specification range conform to ANSI standards applicable in the United States and Canada. This standardization means that any compliant replacement unit of the correct type will meet the same dimensional and electrical specifications as the original.
• The Cavalier's headlight specifications reflect three distinct technologies across its production span: sealed beam rectangular units in the earlier years, transitioning to single-filament halogen bulbs, and then to dual-filament halogen bulbs in the later years. Each technology involves a different replacement procedure, with sealed beam units requiring full assembly replacement and halogen types allowing bulb-only replacement.