The International 8100 uses a 1156 bulb size for front turn signal applications and a 1157 bulb size for rear turn signal functions. The replacement chart covers vehicle production spanning 1992 to 1997.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The International 8100 uses two distinct bulb types across its turn signal system: the 1156 for the front and the 1157 for the rear, covering model years 1992-1997 without variation.
Both the 1156 and 1157 are ANSI-standardized bulbs recognized across the United States and Canada, operating on a 12-volt electrical system.
The 1156 is a single-filament bulb, meaning it serves one lighting function only. It carries a wattage rating of 21W and uses a BA15s bayonet base, which features a single locating pin on the base collar.
The 1157 is a dual-filament bulb, supporting two separate lighting functions from a single housing. It carries wattage ratings of 21W and 5W for its respective filaments and uses a BAY15d bayonet base, which features two offset pins to prevent incorrect installation.
The BA15s base of the 1156 and the BAY15d base of the 1157 are physically incompatible with each other. The pin configurations differ, so the front and rear bulbs are not interchangeable despite sharing the same operating voltage.
The dual-filament design of the 1157 in the International 8100 rear turn signal position allows a single bulb to handle both the turn signal function at 21W and a secondary lower-intensity function at 5W, such as a running or brake light role, depending on circuit configuration.