Chevrolet Cobalt Tail Light Bulb Size

The Chevrolet Cobalt tail light utilizes 3157 and 2458 bulb sizes for the rear lighting components. Data for the specific bulbs covers the range from 2005 through 2010.

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
2005-2010	3157

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3157

Other Locations

Additional Notes

The Chevrolet Cobalt uses the 3157 bulb for its tail lights across the 2005-2010 model years.
The 3157 is an ANSI-standardized bulb type, meaning its specifications are governed by a formal industry standard recognized in both the United States and Canada.
This bulb follows the T25 wedge form factor, a designation that refers to its physical profile and base type used for mounting and electrical contact.
The 3157 operates on a 12-volt circuit, consistent with the standard electrical systems found in passenger vehicles.
Its dual-filament design supports two distinct brightness levels within a single bulb, with a 27-watt filament serving the brighter function and a 7-watt filament serving the dimmer function.
In a tail light application, the higher-wattage filament typically activates as the brake light, while the lower-wattage filament serves as the running light.
The 3157 designation is part of a closely related bulb family that includes types such as the 3156 and 3057, which share similar physical housings but differ in filament configuration or wattage, making substitution a matter requiring attention to electrical compatibility.