International 8300 front turn signal bulbs use 1156 size while rear turn signal bulbs use 1157 size. The replacement chart covers vehicle production spanning 1992 to 1994.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The International 8300 uses two distinct bulb types across its turn signal positions for the 1992-1994 model years: the 1156 at the front and the 1157 at the rear.
The 1156 is a single-filament bulb operating at 12V and 21W, fitted with a BA15s bayonet base. The single filament means it serves one lighting function only, which is consistent with its use in a dedicated turn signal position.
The 1157 is a dual-filament bulb rated at 12V with two wattage outputs, 21W and 5W, and uses a BAY15d bayonet base. The dual-filament design allows it to serve two separate lighting functions from a single housing, such as turn signaling and running light operation simultaneously.
Both the 1156 and 1157 are ANSI-standardized bulbs recognized across the United States and Canada, meaning they conform to a defined set of electrical and physical specifications within those markets.
The BA15s base of the 1156 and the BAY15d base of the 1157 are not interchangeable. The BAY15d base features offset pins that physically prevent it from being seated in a BA15s socket, and vice versa, which guards against incorrect installation between the front and rear positions.
Although both bulbs share the same 12V operating voltage and the same 21W output on their primary filament, the 1157 carries an additional 5W filament that the 1156 does not, making the two bulbs functionally and physically distinct despite their surface similarities.