Saturn L200 front turn signal bulbs utilize 3357NA or 3457 size specifications, while rear turn signal bulbs require 3157 or P21W size bulbs. The replacement chart covers 2001 to 2003 model years with corresponding bulb size data.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Saturn L200 front turn signal for 2003 uses the 3357NA bulb, while the 2001-2002 model years use the 3457. These are distinct bulb types and are not interchangeable with each other despite sharing the same T25 wedge form factor, as one is single-filament and the other is dual-filament.
The 3357NA is a single-filament T25 wedge bulb rated at 12V and 27W. Its natural amber glass produces the required turn signal color without relying on a colored lens or socket.
The 3457 is a dual-filament T25 wedge bulb rated at 12V with a 27W primary filament and a 7W secondary filament. The secondary filament allows the same bulb to serve a secondary lighting function, such as parking or running light duty, alongside the turn signal function.
The 3157 rear turn signal bulb used on the 2003 L200 shares the same dual-filament T25 wedge construction and 12V/27W/7W ratings as the 3457 front bulb, though the two part numbers reflect different contact configurations and are not cross-compatible without verification.
The rear turn signal for the 2001-2002 Saturn L200 uses the P21W, which follows the ECE standard rather than the ANSI standard used by all other bulbs in these specifications. This reflects a different engineering choice for that position in those model years.
The P21W uses a BA15s bayonet base, which is physically incompatible with the wedge-base sockets used by the T25-type bulbs. A vehicle position calling for a P21W cannot accept a wedge bulb without a socket adapter.
The P21W is rated at 12V and 21W, making it lower in wattage than the 27W primary filament of the T25 dual-filament bulbs used elsewhere in these specifications. Substituting one for the other would alter the electrical load on the turn signal circuit.
The front and rear turn signal bulb types on the 2003 L200 differ from each other, with the front using a single-filament 3357NA and the rear using a dual-filament 3157. This means the two positions serve different functional roles despite both being part of the turn signal system.