The Oldsmobile Regency uses a 9005 bulb size for high beam headlights and a 9006 bulb size for low beam headlights. The replacement chart covers vehicle production years from 1997 to 1998 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.
The Oldsmobile Regency uses the 9005 bulb for high beam headlights across both the 1997-1998 model years, and the 9006 for low beam headlights across the same span.
Both the 9005 and 9006 are ANSI-standardized halogen bulbs recognized in the United States and Canada, meaning they conform to a defined set of electrical and physical specifications rather than being proprietary to any single manufacturer.
The 9005 is a single-filament halogen bulb rated at 12V and 65W, fitted with a P20d base. Single-filament construction means the bulb serves one lighting function only, in this case high beam output.
The 9006 is also a single-filament halogen bulb rated at 12V but draws 55W, which is 10 watts less than the 9005. It uses a P22d base for the low beam position.
The P20d and P22d base designations on the 9005 and 9006 respectively are physically distinct, and the two bulbs are not interchangeable despite their similar appearance and shared voltage rating.
The wattage difference between the 9005 and 9006 reflects their intended roles, as high beam headlights are generally designed to project light farther down the road and therefore draw more power than low beam units.