Buick Encore GX Headlight Bulb Size

Additional Notes

• The H9 and 9005 bulbs share the same 12V, 65W electrical rating, yet they use different base types, the H9 uses a PGJ19-5 base while the 9005 uses a P20d base, making them physically non-interchangeable despite identical wattage.
• The H11 and H7 bulbs both operate at 12V and 55W but differ in base type, the H11 uses a PGJ19-2 base and the H7 uses a PX26d base, which means they are not interchangeable with each other.
• The H9 is an ECE-standard bulb, meaning it was originally developed for European and worldwide markets, though it carries US approval as well.
• The 9005 follows the ANSI standard used in the US and Canada, distinguishing it from the ECE-standard bulbs that appear elsewhere in the Buick Encore GX specifications.
• The 2020 Buick Encore GX high beam and low beam specifications each carry a "With Halogen Capsule Headlamps" condition, indicating that the listed bulb sizes apply only to that specific headlamp configuration.
• The low beam bulb changed from H11 in 2021 to H7 in 2023, representing a base type change from PGJ19-2 to PX26d, which affects physical fitment.
• The high beam bulb remained H9 across the 2021-2023 model years, indicating consistent fitment for that function over that period.
• All four bulb types listed across these specifications are single-filament halogen bulbs, meaning each bulb serves only one lighting function rather than combining two functions in a single unit.
• The H7 holds approval in the US and Japan in addition to its ECE certification, giving it broader regulatory acceptance than the H11, which is approved in the US but not specifically noted for Japan.