Chevrolet Cobalt Map Light Bulb Size

Additional Notes

• The Chevrolet Cobalt map light draws from two distinct bulb types across its production run: the 192 and the 12961, both sharing the T10 miniature wedge form factor but differing in wattage.
• The 192 bulb is an ANSI-standardized type distributed across the US and Canadian markets, operating at 12 volts and 3 watts.
• The 12961 is a Philips part number designation rather than an industry-wide standard, operating at 12 volts and 5 watts with a W2.1x9.5d base specification.
• The W2.1x9.5d base on the 12961 refers to a wedge base with a 2.1mm wire contact width and a 9.5mm insertion depth, which is the defining physical characteristic of the T10 wedge family.
• The Chevrolet Cobalt (2008-2010) uses the 192 bulb for the map light position.
• The 2005-2007 model years use the 12961 bulb instead, representing a different wattage rating despite the shared T10 form factor.
• Although both the 192 and 12961 are T10 wedge bulbs and are physically interchangeable in terms of socket fit, their wattage values differ by 2 watts, which is a relevant consideration for socket heat ratings and circuit load.
• The 192 is a widely sourced ANSI-coded bulb, meaning it is produced by multiple manufacturers under the same standardized designation, whereas the 12961 is tied to Philips nomenclature.