The International 4800 front turn signal uses a 1156 bulb size while the rear turn signal requires a 1157 bulb size. 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 4800 uses two distinct bulb types across its front and rear turn signal positions for the 1992-1997 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, and is recognized under ANSI standards in both the United States and Canada.
The 1157 is a dual-filament bulb operating at 12V with filaments rated at 21W and 5W respectively, fitted with a BAY15d bayonet base, and also carries ANSI recognition in the United States and Canada.
The difference in base type between the two bulbs is a critical fitment factor. The BA15s base of the 1156 has a single contact pin, while the BAY15d base of the 1157 has two offset contact pins, making the two bulbs physically non-interchangeable.
The dual-filament design of the 1157 allows the rear turn signal housing to serve more than one electrical function, with the lower-wattage 5W filament typically used for a secondary lighting role such as a running or parking light.
The single-filament 1156 at the front is dedicated solely to the turn signal function, as its construction does not support a secondary filament circuit.
Both the 1156 and 1157 operate on a 12V system, which is consistent with standard automotive electrical architecture in light and medium-duty vehicles of that era.