The Buell XB12R Firebolt front turn signal bulb size measures 5008 or 232, while the rear turn signal bulb size measures 5008. The replacement chart covers vehicle production spanning 2004 to 2009.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 5008 bulb is the dominant type across the turn signal specifications for the Buell XB12R Firebolt, appearing in both front and rear positions across most model years covered.
The 5008 is an ANSI-standard single-filament bulb rated at 12 volts, fitted with a BA15s bayonet base. It is a lower-wattage variant of the 1156 bulb, which shares the same BA15s base and general form factor.
Because the 5008 and 1156 share the same BA15s bayonet base, physical fitment between the two is possible, but their wattage difference means they are not direct electrical equivalents and should not be treated as interchangeable without accounting for that distinction.
The 232 bulb is an ANSI-standard festoon type rated at 12 volts and 3 watts, mounted via an SV8.5 base. Festoon bulbs seat by compression between two end caps rather than by a bayonet or screw mechanism, which is a fundamentally different mounting method from the BA15s base used by the 5008.
The front turn signal position on the 2007 Buell XB12R Firebolt takes a 232 bulb, while every other model year in the front position, from 2004-2006 and 2008-2009, takes a 5008. The rear turn signal position takes a 5008 across all listed years.
The physical and electrical differences between the 232 festoon and the 5008 bayonet bulb mean the two types are not interchangeable, and substituting one for the other in the 2007 front turn signal position would require a socket incompatible with the other years.