The Buick Regal TourX uses H7 bulb size for both high beam and low beam headlight applications. The replacement chart covers 2018 to 2020 vehicle production 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.
The Buick Regal TourX uses the H7 bulb for both high beam and low beam headlights across the 2018-2020 model years, and this applies exclusively to vehicles equipped with halogen capsule headlamps.
The H7 is a single-filament halogen bulb, meaning it serves only one lighting function per unit. Because both the high beam and low beam positions in the Regal TourX require the H7, two separate bulbs handle the two distinct beam functions.
The H7 operates at 12 volts and 55 watts, which are standard ratings for halogen headlight bulbs in passenger vehicles.
The H7 bulb uses a PX26d base, a two-pin connector type that is not interchangeable with other common bases such as the P43t used by H4 bulbs or the P14.5s used by H1 bulbs.
The H7 is an ECE-standard bulb, meaning it was developed under European regulations and is widely used in vehicles sold across Europe and other international markets. It also carries approval for use in the United States and Japan.
Because the H7 specification for the Regal TourX is tied to the halogen capsule headlamp configuration, vehicles equipped with a different headlamp system would not share this bulb fitment.