Harley-Davidson FLHTCUTG Tri Glide Ultra Brake Bulb Size

Harley-Davidson FLHTCUTG Tri Glide Ultra uses a 3157 bulb size for brake applications. The replacement chart covers 2011 to 2023 model 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.

Bulb Size by Year Range

Years	US Type	EU Type	Shop
2022-2023	3157	P27/7W	Check Price
2011-2020	3157	P27/7W	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3157	Check Price

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Additional Notes

The Harley-Davidson FLHTCUTG Tri Glide Ultra uses the 3157 bulb for the brake light position across the 2011-2023 model years covered in these specifications, with 2021 not represented in the data.
The 3157 is an ANSI-standardized bulb type, meaning its specifications are governed by a formal industry standard recognized in both the United States and Canada.
This bulb follows the T25 wedge form factor, a designation that describes its physical shape and base type, which determines physical fitment into the socket.
The 3157 operates on a 12-volt electrical system, consistent with the standard automotive and powersports electrical architecture found in most production vehicles.
As a dual-filament bulb, the 3157 contains two separate filaments within a single housing, rated at 27 watts for the high-intensity filament and 7 watts for the low-intensity filament, allowing it to serve both brake and running light functions from one unit.
The higher 27W filament activates when the brake is applied, producing a noticeably brighter output than the 7W running light filament, which is a deliberate safety characteristic of dual-filament brake bulb designs.
Because the 3157 is an ANSI-standardized type, it is produced by multiple manufacturers and is widely available as a direct replacement in both incandescent and LED-compatible variants, provided the socket and electrical system support the chosen format.
The consistent use of a single bulb type across all listed model years indicates that the brake light socket and housing design remained unchanged throughout the 2011-2023 production span covered by these specifications.