Acura RSX Headlight Bulb Size

Acura RSX headlight bulbs utilize 9005 size for high beam and H1 size for low beam applications. Replacement chart data spans 2002 to 2006 model 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
2005-2006	9005	HB3	Check Price
2002-2004	H1	H1	Check Price

Low Beam Headlight

Years	Bulb Type	Shop
2002-2006	H1	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Single-filament halogen bulb with P20d base. 12V, 65W.	9005	Check Price
ECE standard (Europe & worldwide). Single-filament halogen bulb with P14.5s base. Also approved in the US and Japan. 12V, 55W.	H1	Check Price

Other Locations

Additional Notes

The H1 bulb follows the ECE standard, which is recognized across Europe and worldwide, and also carries approval in the United States and Japan. It operates at 12V and 55W, uses a single filament, and fits a P14.5s base.
The 9005 bulb follows the ANSI standard used in the United States and Canada. It is a single-filament halogen bulb rated at 12V and 65W, and it seats into a P20d base.
The H1 and 9005 bulbs use different base types, P14.5s and P20d respectively, meaning the two are not interchangeable despite both being single-filament halogen designs.
The Acura RSX uses the H1 bulb across all five model years (2002-2006) for the low beam headlight position, making it the consistent fitment for that application throughout the vehicle's production run.
For the high beam headlight, the Acura RSX (2002-2004) requires the H1 bulb, while the 2005-2006 model years require the 9005 bulb, indicating a mid-production change in that position.
Because the high beam position shifted from H1 to 9005 between the 2004 and 2005 model years, selecting the correct bulb for that socket requires attention to the specific model year rather than treating the RSX as a single uniform fitment.