Chevrolet Corvette Automatic Transmission Indicator Bulb Size

The Chevrolet Corvette automatic transmission indicator utilizes bulb sizes 194, 194NA, 161, 1895, 1816, 257, 57, and 51. Available data covers the range of 1953 through 2004.

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
1997-2004	194
1990-1996	194NA
1985-1989	194
1984	161
1979-1982	161
1973-1975	1895
1968-1970	1895
1964-1967	1816
1962-1963	257
1955-1957	57
1953-1954	51

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 3.78W.	194
ANSI standard (US & Canada). Miniature wedge bulb (T10), natural amber glass. 12V, 3.78W.	194NA
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 1W.	161
ANSI standard (US & Canada). Miniature wedge bulb (T5). 12V, 0.9W.	1895
ANSI standard (US & Canada). Miniature wedge bulb (T3.25). 12V, 4W.	1816
ANSI standard (US & Canada). Festoon or BA9s base instrument bulb. 12V, 2W.	257
ANSI standard (US & Canada). Single-filament bulb with BA9s base. 12V, 1W.	57
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 2W.	51

Other Locations

Additional Notes

The Chevrolet Corvette automatic transmission indicator uses eight distinct bulb types across its production history: 194, 194NA, 161, 1895, 1816, 257, 57, and 51, all conforming to ANSI standards for the US and Canadian markets.
The 194 bulb is the most widely specified type across the Corvette's automatic transmission indicator fitments, covering model years 1985-1989 and 1997-2004. It is a T10 miniature wedge bulb rated at 12V and 3.78W.
The 194NA bulb, specified for 1990-1996, shares the same T10 wedge form factor, voltage, and wattage as the standard 194 but features natural amber-tinted glass. This tinting is a factory-applied optical filter rather than a difference in electrical characteristics.
Because the 194 and 194NA share identical T10 form factors and 12V/3.78W ratings, the physical fitment is the same across 1990-2004, though the amber glass of the 194NA produces a different light color output compared to the clear 194.
The 161 bulb, used in the Chevrolet Corvette for 1979-1982 and 1984, is also a T10 miniature wedge type but is rated at only 1W, making it significantly lower in wattage than the 194 series despite sharing the same base format.
The 1895 bulb, specified for 1968-1970 and 1973-1975, is a T5 miniature wedge type rated at 12V and 0.9W. The T5 designation indicates a narrower tubular envelope than the T10 used in later years, and the two are not interchangeable.
The 1816 bulb, covering 1963-1967, uses a T3.25 wedge form and is rated at 12V and 4W, giving it the highest wattage of any wedge-type bulb in these specifications.
The 257 bulb, specified for 1962-1963, is rated at 12V and 2W and is listed as either a festoon or BA9s base instrument bulb, meaning two physically distinct base configurations share this ANSI designation.
The 57 bulb, used for 1955-1957, is a single-filament type with a BA9s bayonet base rated at 12V and 1W. The BA9s base uses a 9mm bayonet fitting, which is not compatible with the wedge-base bulbs used in later model years.
The 51 bulb, specified for the 1953-1954 Corvette, uses a BA15s bayonet base rated at 12V and 2W. The BA15s is a 15mm single-contact bayonet fitting, making it a larger base format than the BA9s used in the 57 bulb and physically incompatible with all other bulb types listed in these specifications.