Autocar AT License Plate Bulb Size

The Autocar AT license plate light requires 1157 and 198 bulb sizes for the specific components listed in the provided technical data. The available information covers a time range from 1983 through 1988.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
1985-1988	1157
1983-1984	198

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. 12V, 21W/5W.	1157
ANSI standard (US & Canada). Miniature wedge bulb (T5). 12V, 2W.	198

Other Locations

Additional Notes

The Autocar AT uses two distinct bulb types for its license plate across the 1983-1988 model years: the 1157 and the 198.
The 1157 is a dual-filament bulb rated at 12V with a 21W main filament and a 5W secondary filament, mounted on a BAY15d bayonet base.
The BAY15d bayonet base features offset pins, which physically prevents incorrect single-filament bulbs from being seated in the socket.
The 198 is a miniature wedge bulb in the T5 form factor, rated at 12V and 2W, making it significantly lower in wattage than the 1157.
Both the 1157 and the 198 conform to ANSI standards applicable in the United States and Canada.
The Autocar AT (1985-1988) uses the 1157 for its license plate position, while the 1983-1984 model years use the 198.
The 1157 and the 198 are not interchangeable. The difference in base type, wattage, and filament configuration makes one a direct incompatible substitute for the other.
The wedge base of the 198 and the BAY15d bayonet base of the 1157 require different socket housings, reinforcing that fitment is year-specific for the Autocar AT.