Buick Park Avenue Headlight Bulb Size

Additional Notes

• The Buick Park Avenue uses the 9005 bulb for high beam headlights and the 9006 bulb for low beam headlights across all model years from 1991-2005.
• The 9005 is a single-filament halogen bulb operating at 12V and 65W, built to the ANSI standard applicable in the United States and Canada, and fitted with a P20d base.
• The 9006 is also a single-filament halogen bulb operating at 12V but rated at 55W, likewise conforming to the ANSI standard for the United States and Canada, and fitted with a P22d base.
• Because the 9005 and 9006 share a similar body profile but carry different base types, the P20d and P22d bases are not interchangeable, meaning the high beam and low beam positions each accept only their designated bulb.
• The 10-watt difference between the 9005 and 9006 reflects their intended functions, as the higher-wattage 9005 produces greater light output suited to high beam use, while the lower-wattage 9006 is calibrated for the controlled beam pattern required at low beam.
• Both bulb types are governed by ANSI standards, which define consistent electrical and physical specifications, allowing bulbs from different manufacturers to remain interchangeable within each respective type.
• The single-filament construction of both the 9005 and 9006 contrasts with dual-filament bulbs such as the 9004 or 9007, which handle both beam functions within a single housing. The Park Avenue uses separate bulbs for each function.
• The fitment of the same bulb sizes across the entire 1991-2005 production span of the Park Avenue indicates that both headlight positions remained unchanged throughout the vehicle's production run.