GMC Sierra License Plate Bulb Size

Additional Notes

• The GMC Sierra license plate bulb specifications reference four distinct bulb types across the model's history: the 194, 168, 192, and 12961.
• All four bulb types share the T10 miniature wedge form factor, which is a small, wedge-shaped base design commonly used in low-current automotive lighting applications.
• The 194, 168, and 192 are ANSI-standardized bulbs recognized in both the US and Canada, while the 12961 is a Philips part number designation rather than an ANSI standard.
• The 12961 uses a W2.1x9.5d base and operates at 5W, making it the highest-wattage bulb among the four types listed. The 168 follows at 4.9W, the 194 at 3.78W, and the 192 at 3W.
• Despite sharing the T10 wedge form factor, the wattage differences among these bulbs mean they are not necessarily interchangeable without confirming socket and circuit compatibility for a specific model year and trim.
• The GMC Sierra (1999-2006) and (2021-2024) use the 194 bulb for the license plate position, representing the most frequently specified bulb type across the Sierra's history in these specifications.
• In 2019 and 2020, the Sierra 1500 uses the 194 bulb while the 3500 HD uses the 12961, indicating that trim level is a critical factor in bulb selection for those years.
• A similar trim-level split occurs in 2014, where the Sierra 1500 takes the 12961 and the 3500 HD takes the 168, and again in 2007 and 2008, where the 3500 HD uses the 168 and the 1500 uses the 192.
• The 12961 is specified across the Sierra lineup from 2015-2018 without any trim distinction, covering all variants in those years under a single bulb type.
• The 192 bulb, rated at 3W, is the lowest-wattage type in these specifications and appears only in the 2007 and 2008 Sierra 1500, making it the most narrowly applied bulb across the entire model range covered.