Saturn Sky Back Up Light Bulb Size

Saturn Sky back up light bulb uses a 3157 size bulb for the reverse lighting application. The replacement chart covers 2007 to 2010 vehicle production years with corresponding bulb specifications.

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
2007-2010	3157

Bulb Specifications

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

Other Locations

Additional Notes

The Saturn Sky uses the 3157 bulb for the back up light across all documented model years, spanning 2007-2010.
The 3157 is an ANSI-standardized bulb type, meaning its physical and electrical specifications are governed by a recognized North American standard applicable in both the United States and Canada.
The 3157 is a dual-filament bulb, housing two separate filaments within a single unit. One filament operates at 27W and the other at 7W, allowing the bulb to serve two distinct lighting functions at different brightness levels.
The bulb operates on a 12V electrical system, which is consistent with standard automotive voltage.
The 3157 follows the T25 wedge form factor. The T25 designation refers to the bulb's body size, and the wedge base type means it is held in place by the socket through friction rather than a bayonet or screw mechanism.
Because the 3157 is a dual-filament type, single-filament substitutes such as the 3156 are not electrically equivalent and would not replicate the same wiring behavior in the socket, even though the physical base may fit.