The Volvo XC70 side marker requires a 12961 bulb size for the exterior lighting system. Data for the specified component covers the range from 2008 through 2016.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 12961 is a Philips part number designating a T10 miniature wedge bulb with a W2.1x9.5d base, rated at 12V and 5W. The T10 designation refers to the bulb's tubular form factor, and the W2.1x9.5d base is a wedge-type fitting that requires no separate metal socket pins, as the glass pinch itself acts as the base.
The 5008 follows the ANSI standard used in the United States and Canada. It is a single-filament bulb with a BA15s bayonet base, operating at 12V. The BA15s base uses a single contact point at the bottom and two side pins offset at the same height, distinguishing it from dual-filament bayonet variants.
The 5008 is described as a lower wattage variant of the 1156. The 1156 is a widely used automotive bayonet bulb, and the 5008 shares the same BA15s base configuration while drawing less power, making the two types physically similar but not electrically identical.
The Volvo XC70 uses the 12961 bulb for the front side marker across the full 2003-2016 model year range covered in the specifications, representing an uninterrupted fitment across all listed years for that position.
The rear side marker position on the Volvo XC70 is not served by a single bulb type across all listed years. The 5008 applies to the 2005-2007 model years, while the 12961 applies to the 2008-2016 model years, indicating a change in rear side marker bulb specification between those two groups.
Because the 5008 uses a BA15s bayonet base and the 12961 uses a W2.1x9.5d wedge base, the two bulb types are not interchangeable. The socket designs are physically incompatible, and substituting one for the other in the rear side marker position is not possible without modification.
The 12961 wedge base is a push-in fitment, while the BA15s bayonet base of the 5008 requires a twist-lock installation. These are fundamentally different retention mechanisms, which reinforces the incompatibility between the two bulb types used across the XC70's rear side marker history.
Both the front and rear side marker positions on the 2008-2016 XC70 use the same 12961 bulb, meaning a single bulb type serves all four side marker sockets on those model years.