Ford Transit Tail Light Bulb Size

Ford Transit tail light bulbs use a P21/5W size, also designated as 3057, for vehicles across multiple production generations. The replacement chart covers 2015 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	Bulb Size
2023	P21/5W
2015-2020	3057

Bulb Specifications

Description	Bulb Size
ECE standard (Europe & worldwide). Dual-filament signalling bulb with BAY15d bayonet base. 12V, 21W/5W.	P21/5W
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3057

Other Locations

Additional Notes

The Ford Transit tail light specifications cover model years 2015-2023, with two distinct bulb types used across that span.
The 3057 is the most frequently specified tail light bulb in these records, appearing in the Ford Transit from 2015-2020.
The 3057 follows the ANSI standard, which governs bulb specifications in the United States and Canada. It is a dual-filament bulb in a T25 wedge base configuration, rated at 12V with a 27W high filament and 7W low filament.
Dual-filament bulbs serve two functions within a single housing, typically combining stop light and tail light operation through separate filaments at different wattages.
The 2023 Ford Transit shifts to the P21/5W bulb type, which follows the ECE standard used in Europe and worldwide markets.
The P21/5W is also a dual-filament bulb, rated at 12V with a 21W high filament and 5W low filament, and it uses a BAY15d bayonet base rather than a wedge base.
The BAY15d bayonet base of the P21/5W and the T25 wedge base of the 3057 are physically incompatible, meaning these two bulb types are not interchangeable despite both being dual-filament 12V units.
The wattage ratings also differ between the two types: the 3057 runs higher at 27W/7W compared to the P21/5W at 21W/5W, which reflects the differing power tolerances of each standard.