Buick Encore Headlight Bulb Size

Additional Notes

• The 9008 bulb is a dual-filament halogen type rated at 12V with a 65W high beam filament and a 55W low beam filament, using a P26t base. Its dual-filament design means a single 9008 bulb handles both high and low beam functions within one housing.
• The 9005 bulb is a single-filament halogen type rated at 12V and 65W, using a P20d base. It operates exclusively as a high beam bulb and cannot serve a low beam function on its own.
• The H11 bulb is a single-filament halogen type rated at 12V and 55W, using a PGJ19-2 base. It follows the ECE standard used across Europe and worldwide, though it also carries approval for use in the United States.
• For the 2021 Buick Encore, two distinct headlight configurations exist. One configuration uses the 9008 bulb for both high and low beam positions, while the other uses a 9005 for the high beam and an H11 for the low beam, reflecting separate single-filament bulbs per function.
• The 9008 and 9005 follow the ANSI standard applicable to the United States and Canada, whereas the H11 follows the ECE standard, meaning the two systems originate from different regulatory frameworks despite both being present in the Encore's specifications.
• Because the 9008 consolidates both beam functions into one dual-filament bulb, it is not interchangeable with the separate 9005 and H11 pairing used in the alternative 2021 configuration, even though both setups serve the same headlight positions.
• The 9005 and H11 bulbs use physically different bases, P20d and PGJ19-2 respectively, which prevents cross-substitution between the high beam and low beam sockets in configurations that use them as separate single-filament bulbs.
• From 2013-2020, the Buick Encore used the 9005 for the high beam and the H11 for the low beam. The 2017-2020 entries carry a "With Halogen Capsule Headlamps" qualifier, indicating that at least one other headlamp technology was available during those years.
• The 9005 operates at 65W while the H11 operates at 55W, meaning the high beam circuit in single-filament configurations draws more power than the low beam circuit in the same vehicle.