Mercedes-Benz CL600 Turn Signal Bulb Size

Additional Notes

• The Mercedes-Benz CL600 front turn signal uses the PY24WNA bulb across the 2007-2014 model years. This bulb operates on a PGU20-4 base at 12V and 24W, and it is the amber-glass variant of the ECE PY24W standard adapted to meet ANSI requirements for the US and Canadian markets.
• The PGU20-4 base on the PY24WNA is a wedge-pin type specific to certain European-origin vehicle platforms. It is not interchangeable with the BA15s or BAY15d bayonet bases found on other bulbs listed in these specifications.
• The 2357NA bulb appears in the front turn signal position for the 1998-1999 and 2005-2006 model years. It is a dual-filament bulb rated at 26.9W on the primary filament and 8W on the secondary, using a BAY15d bayonet base with natural amber glass at 12V.
• The dual-filament design of the 2357NA means it is not a direct substitute for single-filament bulbs such as the 1156NA, despite both sharing a similar bayonet-style base family. The BAY15d base on the 2357NA has offset pins to prevent incorrect installation, whereas the BA15s base on the 1156NA has a single contact pin.
• The 1156NA is a single-filament bulb with a BA15s bayonet base, rated at 12V and 21W with natural amber glass. It serves the front turn signal position on the CL600 for the 2001-2004 model years and the rear turn signal position across several model years including 1998-1999, 2001-2002, 2005-2006.
• The rear turn signal on the 2003 CL600 uses the PY21W, which is an ECE-standard bulb rather than an ANSI-standard one. Its BAU15s base has an offset pin arrangement distinct from the BA15s base of the 1156NA, making the two physically non-interchangeable despite both being single-filament 21W bulbs.
• The 12271NA, used in the rear turn signal position for the 2007-2010 CL600, is identified by an OEM part number rather than an ANSI or ECE designation. It is a natural amber glass variant rated at 12V, and its fitment is specific to the housing design of that generation.
• The 12496, appearing in the rear turn signal for the 2004 CL600, carries a Philips/Osram part number and is classified as a specialty halogen application at 12V. Its designation falls outside the standard ANSI and ECE numbering systems, indicating it was sourced as a manufacturer-specific component.
• The "NA" suffix present on several bulb designations, including the 1156NA, 2357NA, and PY24WNA, denotes natural amber glass coloring. This distinguishes them from clear-glass equivalents such as the 1156 or 2357, which rely on an amber-tinted lens housing to produce the required signal color.
• Substituting a clear-glass bulb for an NA-designated bulb in a clear-lens housing would not produce the amber output required by North American turn signal regulations, making the NA suffix a functionally critical part of the specification rather than a cosmetic distinction.