The GMC Envoy XL 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 2002 to 2006 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 GMC Envoy XL uses the 9005 bulb for high beam headlights and the 9006 bulb for low beam headlights across all model years from 2002-2006.
Both the 9005 and 9006 are single-filament halogen bulbs operating on a 12-volt system, meaning each bulb handles only one lighting function rather than combining high and low beam duties in a single unit.
The 9005 high beam bulb is rated at 65 watts, while the 9006 low beam bulb is rated at 55 watts, reflecting the higher output typically associated with high beam applications.
The 9005 uses a P20d base and the 9006 uses a P22d base, making the two bulbs physically non-interchangeable despite their otherwise similar construction.
Both bulb types conform to ANSI standards recognized in the United States and Canada, placing them within a standardized specification system that governs electrical and physical properties.
Because the high and low beam functions rely on separate single-filament bulbs, a failure in one beam does not affect the operation of the other.