The Buick Terraza high beam and low beam headlight bulbs both utilize an H11 size. The replacement chart covers vehicle production spanning 2005 to 2007.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The H11 is a single-filament halogen bulb operating at 12 volts and 55 watts, fitted with a PGJ19-2 base. It follows the ECE standard, which is a European-origin regulatory framework also recognized in the United States.
The Buick Terraza uses the H11 bulb for both the high beam and low beam headlight positions across all three model years covered, 2005-2007.
Because the high beam and low beam positions share the same H11 specification, both sockets accept the same physical bulb type. This is a result of the H11 being a single-filament design, meaning separate bulbs handle each lighting function rather than one dual-filament unit serving both.
The PGJ19-2 base is a keyed connector specific to the H11 and a small number of closely related bulb types. Bulbs from other families with visually similar bases may not seat or lock correctly, making base type a critical factor in fitment.
The H11 belongs to a family that includes the H8, H9, and H16 types, all of which share the PGJ19-2 base but differ in wattage and light output. These variants are not direct substitutes for the H11 in applications where the original specification calls for 55 watts.