The Mercedes-Benz S350 front turn signal requires a PY24WNA, 2357NA, or 1157 bulb size, while the rear turn signal uses a PY21W or 1156NA bulb size. The replacement chart covers 1994 through 2013 vehicle production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mercedes-Benz S350 front turn signal specifications list three distinct bulb types across the covered model years: PY24WNA, 2357NA, and 1157, each representing a different base type and filament configuration.
The PY24WNA is the most recent front turn signal bulb in the S350 specifications, appearing in the 2012-2013 model years. It follows the ANSI standard for the US and Canadian markets and uses a PGU20-4 base, operating at 12V and 24W with a single filament.
The 2357NA is a dual-filament bulb rated at 12V with a high filament draw of 26.9W and a low filament draw of 8W. It uses a BAY15d bayonet base and features natural amber glass to produce the required amber signal color without a separate amber lens.
The 1157 shares the same BAY15d bayonet base as the 2357NA, making the two physically similar in mounting. However, the 1157 draws 21W on its high filament and 5W on its low filament, which differs from the 2357NA's wattage ratings, and it lacks the natural amber glass coating.
Because the 1157 and 2357NA share the BAY15d base, they are physically interchangeable in socket fitment, but the difference in wattage and the absence of amber glass on the 1157 means substituting one for the other affects both light output and color compliance.
The rear turn signal specifications for the S350 include two distinct base types: the BAU15s bayonet base on the PY21W and the BA15s bayonet base on the 1156NA. These two bases are not interchangeable, as the BAU15s has an offset pin arrangement while the BA15s has a straight twin-pin arrangement.
The PY21W rear turn signal bulb follows the ECE standard, which is used in European and worldwide markets, in contrast to the ANSI-standard bulbs listed for other positions and years. It operates at 12V and 21W with a single filament and an amber-colored glass envelope.
The 1156NA rear turn signal bulb, listed for the 1994-1995 model years, is a single-filament ANSI-standard bulb with a BA15s base. Its natural amber glass produces the amber signal color, operating at 12V and 21W.
The "NA" suffix present on the PY24WNA, 2357NA, and 1156NA designations indicates a natural amber glass construction. This suffix distinguishes these bulbs from their clear-glass counterparts, which rely on an amber lens in the fixture to produce the required signal color.
Front and rear turn signal positions on the S350 do not share a common bulb type across any of the listed model years, as the front positions use dual-filament or PGU20-4 base bulbs while the rear positions use single-filament bulbs with bayonet bases.