Volkswagen Routan front and rear turn signal bulbs utilize 3457NA and 3157 sizes respectively. The replacement chart covers 2009 to 2014 model year specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Volkswagen Routan uses two distinct bulb types across its turn signal positions for the 2009-2014 model years: the 3457NA for the front and the 3157 for the rear.
Both the 3457NA and 3157 are ANSI-standardized bulbs recognized in the US and Canada, meaning they conform to a defined set of electrical and physical specifications rather than proprietary manufacturer standards.
Both bulbs share the same T25 wedge base form factor and identical electrical ratings of 12V with a dual-filament output of 27W/7W, where the higher wattage filament serves the turn signal function and the lower wattage filament serves a secondary lighting function.
The dual-filament design of both bulbs allows a single unit to perform more than one lighting role within the same housing, which is a common arrangement in combined stop and turn signal assemblies.
The primary distinction between the 3457NA and the 3157 is the glass envelope: the 3457NA features natural amber-tinted glass, while the 3157 uses clear glass.
The "NA" suffix in the 3457NA designation specifically denotes the natural amber coating on the glass, which produces an amber output without relying on a colored lens in the fixture itself.
Because the 3457NA and 3157 share the same T25 base and voltage ratings, physical installation is technically possible in either socket, but substituting one for the other would affect the color output at the front turn signal position.
The front turn signal housing on the Volkswagen Routan is designed to work with the amber glass of the 3457NA, so installing a clear 3157 in that position would alter the emitted light color unless the lens itself provides amber filtration.