The Triumph Thruxton uses a 9003 bulb size for both high beam and low beam headlight applications. The replacement chart covers vehicle production spanning 2004 to 2016 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 Triumph Thruxton uses the 9003 bulb for both high beam and low beam headlight positions across the 2004-2016 model years.
The 9003 is an ANSI-standard halogen bulb recognized in the United States and Canada, operating on a 12-volt system with a dual-filament design rated at 60 watts for high beam and 55 watts for low beam.
The dual-filament construction of the 9003 means a single bulb unit serves both beam functions, which accounts for its use in both the high beam and low beam positions on the Thruxton.
The 9003 bulb uses a P43t base, a bayonet-style mount with a 43mm cap, which determines physical fitment into the headlight housing.
The 9003 standard is functionally equivalent to the European H4 bulb type, sharing the same P43t base and dual-filament configuration, though the designations reflect different regional certification systems.
Because the same bulb type fills both beam positions, a single replacement part number applies to the entire headlight assembly on the Triumph Thruxton for all listed model years.