Geo Prizm License Plate Bulb Size

The Geo Prizm license plate light uses bulb sizes 97 and 168 for the rear exterior illumination. Available information covers the production span from 1989 through 1997.

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
1993-1997	97
1989-1992	168

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 13W.	97
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 4.9W.	168

Other Locations

Additional Notes

The Geo Prizm uses two distinct bulb types for the license plate position across its production run: the 97 for model years 1993-1997 and the 168 for model years 1989-1992.
The 97 bulb is an ANSI-standardized single-filament type rated at 12V and 13W, fitted with a BA15s bayonet base, and is classified as a variant of the 1156 bulb family.
The BA15s designation on the 97 bulb indicates a single-contact bayonet base with a 15mm collar, which is not interchangeable with the BA15d double-contact variant despite sharing the same physical collar size.
The 168 bulb is an ANSI-standardized T10 miniature wedge type rated at 12V and 4.9W, a significantly lower wattage than the 97 bulb used in later model years.
The T10 wedge base of the 168 bulb relies on contact through its lead wires rather than a separate base component, making it physically incompatible with the BA15s bayonet socket used by the 97 bulb.
Both the 97 and 168 bulbs conform to ANSI standards recognized in both the United States and Canada, indicating consistent electrical and physical specifications across those markets.
The 1993 Geo Prizm marks the transition point from the 168 to the 97 bulb for the license plate position, meaning the two bulb types require different sockets and are not interchangeable between model year groups.