Mack CL License Plate Bulb Size

The Mack CL license plate light requires a 1891 bulb size for proper installation and function within the rear lighting assembly. Data for the specific component covers the period from 1991 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
1991-1997	1891

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Miniature wedge bulb (T5). 12V, 2W.	1891

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Additional Notes

The 1891 bulb is the specified license plate bulb size for the Mack CL across all listed model years from 1991-1997.
The 1891 is classified as a T5 miniature wedge bulb, where "T5" denotes a tubular glass envelope with a width of 5/8 of an inch.
The wedge base design means the 1891 bulb relies on its tapered glass pinch to make electrical contact within the socket, rather than using a separate metal base.
The 1891 operates at 12 volts and draws 2 watts, placing it among the lower-wattage miniature bulbs used in automotive lighting applications.
The 1891 carries ANSI standardization recognized in both the United States and Canada, meaning the designation refers to a consistent specification across North American markets.
The T5 wedge form factor is shared by several bulb numbers in the miniature wedge category, and substitution with a different T5 wedge bulb requires verification that voltage and wattage ratings match the 1891 specification to avoid socket or circuit incompatibility.