The Saturn LW300 brake light requires bulb sizes P21/5W, 2458, and 3157 depending on the specific version. Data for the listed components covers the range from 2001 to 2003.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Saturn LW300 brake light circuit uses two distinct bulb standards across its model years. The 2001-2002 models use the ANSI-standard 3157, while the 2003 model uses the ECE-standard P21/5W.
The P21/5W and 3157 are not interchangeable despite both being dual-filament 12V bulbs. The P21/5W uses a BAY15d bayonet base, whereas the 3157 is a T25 wedge-type bulb, making the base configurations physically incompatible.
The wattage ratings also differ between the two brake bulb types. The P21/5W operates at 21W/5W, while the 3157 operates at a higher 27W/7W, meaning the 2003 Saturn LW300 draws less current through its brake filament than the 2001-2002 models.
The Center High Mount Stop Light (CHMSL) on the Saturn LW300 uses miniature T10 wedge bulbs with a printed circuit board twist-lock socket, designated as PC-type bulbs under the ANSI standard.
The CHMSL specification changes between model years. The 2001 model uses the PC168, while the 2002-2003 models use the PC175. These two bulb types share the same T10 wedge form and twist-lock socket design but are not listed as interchangeable within these specifications.
The PC175 and PC168 are both 12V miniature wedge bulbs designed for printed circuit board sockets, a socket type associated with instrument cluster and low-clearance lighting applications rather than standard bulb holders.